ORNL
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AL ORNL 1450

Chemistry

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GENERAL INFORMATION

CONCERNING FLUORIDES .

OAK RIDGE NATIONAL LABORATORY

OPERATED BY

CARBIDE AND CARBON CHEMICALS COMPANY

A DIVISION OF UNION CARBIDE AND CARBON CORPORATION

(=4

POST OFFICE BOX P
OAK RIDGE. TENNESSEE

 
ORNL 1490

This document consists of 22 pages.
Copytaf of 330 copies. Series A.

Contract No. W-Th05-eng-26

AIRCRAFT NUCLEAR PROPULSION DIVISION

GENERAL INFORMATION CONCERNING FLUORIDES

Mary E. Lee

DATE ISSUED

¥

peg 27 que?

OAK RIDGE NATIONAL IABORATORY
Operated by
CARBIDE AND CARBON CHEMICALS COMPANY
A Division of Union Carbide and Carbon Corporation
Post Office Box P
Osk Ridge, Tennessee
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UNCLASSIFIED 3

GENERAL INFORMATION CONCERNING FLUORIDES
Abstract

This report is an addition to ORNL-1252. It is a compilation of
abstracts, taken from Chemical Abstracts (Sec. 4, 1952 through Sec. 22,
1952), containing genergl information concerning the fluorides of aluminum,
bafium, beryllium, calcium, cesium, lead, lithium, magnesium, potassium,

rubidium, sodium, strontium and uranium.

UNCLASSIFIED
A UNCLASSIFIED

CA 46, kO5h

Coating Ferrous Metal with Aluminum or an Aluminum Alloy
Howard L. Grange and Dean K. Hanink (to General Motors Corp.)
U.s. 2,569,097, Sept. 25, 1951

Degrease the steel or ferrous material; if necessary, pickle in acid
and dip in a flux soln. of ZnClp 32, NHRC1 8, and HpO 60 parts. Immerse in
molten salt floating on top of a molten Al or Al alloy coating bath. Hold
in a salt bath at 1300-1400°F until the metal reaches this temp. Then pass
into the molten metal at between 1150 Oto 1600°F and hold there one second or
longer. The satisfactory salt bath consisted of KC1l 47, NaCl 35, NaoAlFg 12,
and AIF, 6%, which is able to dissolve Al and Fe oxides. This salt mixt.
melts a% 1180°F. Addns. of about 20% LiCl lowers the m.p. to 1075°F. Some
control of the thickness of metal coating is obtained by holding the coated
article in the molten salt and on emerging to drain excess coating material.
Excess coating metal also may be removed by an air blast. The steel may be
preheated in a nonoxidizing or reducing atm. before being immersed in the
fused salt bath.

cA 46, 1341b

The Melting Point and Heat of Sublimation of Plutonium Trifluoride
Edgar F. Westrum, Jr., and James C. Wallmann (Univ. of Calif., Berkeley)
J. Am. Chem. Soc. 13, 3530-1 (1951)

In hlgh vacuun and under 10 -2 atm. A the fu51on temp. of PuF
1426 £ 2%, and the solidification temp. 1425 * 3 The AC., of su 1imation
corresponding to an equation based on vapor-pressure data (¢f. Phipps, CA
L4 10560f) is -32 cal/mole degree. A least-squares treatment with an assumed
value of .AC, of =15 cal/mole degree, and 2 arbitrary consts. also fit the
data well and yield the equation log P(mm) = -24,91771 . 7.5513 log T +
38.920, valid from 1200 to 1660°K for the dissocn. pressure and the value
89 kcal/mole for the heat of sublimation of 1400°.

CA 46, 1419b

Corrosion Experiments with Gaseous Boron Trifluoride

F. Hudswell, J. S. 'Nairn, and K. L. Wilkinson (At. Energy Research Estab-
lishment, Harwell, Berks, Engl.)

J. Applied Chem. (London) 1, 333-6 (1951)

Metals, alloys, and other compds. which may be used with BF, were con-
tacted with this gas at 25 cm Hg at temps. up to 200°. The exteqt of re-
action was detd. by the change in the gas pressure over the sample. It was
found that the following can be used in app. for handling dry BF,: stainless
steel, mild steel, Cu, Ni, Monel metal, brass, and Al. The more noble metals

UNCLASSIFIED
and Pyrex glass can be used up to about 200°. Acaldite cementé fired
pyrophyllite, and polytetrafluorocethylene can be used up to 80°. Some
plastics were resistant, but others cannot be used with BF3.

CA 46, 18574

Thermodynamic Functions. Alhc3, 51, Sioe, Sic, A1F3
L. I. Ivanova (Saratov State Univ.)
J. Gen. Chem. U.S.S.R. 21, 491-9 (1951) (Engl. translation)

and N33A1F6 .

See CA 45, 50l1kc.
CA 46, 2240a

Soldium Aluminum Fluoride
Erling Brodal and Hemning Guldhav (to Aktieselskapet Norsk Aluminium Co.)
U.S. 2,567,544, Sept. 11, 1951. - % ST s e
S ni T In presoeee, 08 81 udgge

The production of alk. Na compds. from fluorspar in presence of
silica is described.

CA 46, 3334g

Liquids and Vapors as Heat-Transfer Media in the
Temperature Range of 200 to 400°

Hermann Schulze

Chem.-Ing.-Tech. 23, 565-9 (1951)

Water, fused salts, liquid metals and alloys, and org. substances are
discussed. Some phys. data are given.

CA 46, 3382¢g

Catalytic Properties of Fluorides of Alkali and Alkaline-Earth Metals
A. A. Tolstopyatove (Moscow State Univ.)
Vestnik Moskov. Univ. é, No. 3, Ser. Fiz.-Mat. i Estestven. Nauk No. 2,

k9-57 (1951)

Dehydrogenation-dehydration of EtOH passed at the rate of 0.2 ml/min
over 15 g of ThO, (pptd. from & 10% Th(NO3)) soln. with 20% NH4OH at 50°,
washed and dried at 120°) gave the following % decompn. and gas (% COo,
Caloy, CO, Hp): at 287°, k.14 (1.5, 11.5, 3.1, 84.2); at 338°, 5.8 (3.6,
2,5, 6.8, 65.1); at 348°, 10.4 (4.6, 27.3, 10.9, 57.5); at 360°, 1k.8,
(5.2, 31.3, 9.1, 5&.k); at ¥20°, 43.3 (9.2, 39.1, 6.9, 44.8). Dehydrogena-
tion to AcH predominates at lower temps; the part of dehydration to CoH)
increages with the temp. The apparent activation energies EH, and EHj0,
for dehydrogenation and dehydration, resp., are 14.7 and 21.8 kcal/mole.
At the same feed rate, on 12 g CaF, (pptd. from a 10% soln. of Ca(NO3)s
with 10% NaF, washed and dried at 120°), the data were: at 460°, 2.5%
6

(7.5, 0, 2.7, 89.8); at 495°, &,3 (7.0, 2.1, 4.0, 86.8); at 510°, 7.8 (8.0,
5.2, 3.4, 83.5); at 526°, 11.9 (8.5, 4.9, 5.0, 81.6). The catalytic activity
of CaFp is new. Despite its identical structure with ThOp and the near
equality of the cation and anion radii, the activity of CaF, is considerably
lower, and the part of dehydration is very much smaller; the activation ener-
gies are EH2 = 26.0, EE?O'~J36 keal/mole; CaF, promoted with a trace of Fe
(by pptn. of 10% CaCly, contg. some Fe, with 10% NHJF at 50°) detectable
with NH4CNS, is active at lower temps. With 15 g catalyst, the data are: at
375°, 6.0 (1.6, 2.5, 1.0, 92.7); at 400°, 15.6 (3.5, k.6, 2.5, 89.k); at 4259,
18.2 (3.7, 5.6, 5.4, 85.1); in addn. to these products, about 2% CHj was
found in the gas with this catalyst. It can be only partially regenerated
by air, and the activation energies can be detd. only approx.: “Ho - 35,
EHQO'flJSB kcal/mole. It is striking that E is higher with promoted than with
unpromoted CaFo, although reaction with EtOH begins at lower temps. with the
promoted CaFs. The ratio EHQ/EHQO is approx, comst., = C.7, with ThO» and
with promoted or unpromoted CaF,. For other fluorides, approx. data of the
degrees of decompn. of EtOH are: 15.6 g SrFp (pptd. from 10% Sr(NO3)e with
10% NaF at 50° and dried at 120°), at 345, 394, L26°, resp., 3.1, g.o, 10.49%;
12 g LiF (dried at 120°), at 348, 394, 43k, 450, 48UC, resp., 2.4, 3.7, 2.k,
7.0, 11.7%; 15 g NeF (dried at 120°), at 348, 394, 460°, resp., 1.7, 2.3, 4.6%;
21 g KF, 370 and 460°, resp., 2.3 and 13.0%. Temps of equal catalytic acti-
vity, corresponding to 10% decompn., are: SrF, 425, KF 450, LiF 470, NeF

490, caFy 526°. With SrF,, LiF, and NaF, 85-90% of the gas is Hp, i.e.,
dehydrogenation is by far predominant; with KF, sbout 50% of the gas is Hp,
25% COp, large amts. of CHj and satd. hydrocarbons. Rough values of the
activwation energies are, for LiF and NaF, 8-9 kcal/mole, for SrF, 13
keal/mole.

CA 46, 3hlh1d

Fluorine-Active Substances
Hans Bode and Ernst Klesper (Chem. Staats-inst. Hamburg, Ger.)
7. anorg. u. allgem. Chem. 267, 97-112 (1951)

When gaseous F which is free of HF, reacts with K, Rb, of Cs halides
at low temps. (140-220°), substances higher in F than MF are obtained. The
phenomenon was not observed with Li and Na halides. For Rb and Cs, accord-
ing to the exptl. conditions, a limit formula of MF- seems to be reached.
The reaction mechanism and the structure of the new substances are discussed.

CA 46, 37154

The Importance, Manufacture, and Use of Inorganic Fluorine Compounds
K. Kersten and E. Pieschel (Dohna/Sa, Ger.)
Chem. Tech. (Berlin) 3, 296-8 (1951)

A general discussion is given of the importance and manuf. of HF,
synthetic cryolite, NaF, A1F3, silicofluorides, and fluosilicic acid, and
the use of F salts in the preservation of wood.
T
CA 46, 3816h

Theory of the Electric Breaskdown of Solid Dielectrics
A. A. Vorob'ev and BE. K. Zuvadovskaya (S.M. Kirov Polytech. Inst,, Tomsk)
Doklady Akad. Nauk S§.S.S.R. 81, 375-7 (1951)

It is assumed that elec. breakdown takes place when the energy accumulated
by the electrons and transferred to the lattice is sufficient to break the bond
between lattice points. The energy increment of an electron per sec is Aw =
eBu, where E = fleld strength and u= group velocity, and hence Aw = (eaEe/m)1’(w}
where <o (w) is the time elapsing until a collision, and is a function of w; the
reciprocal 1/ is the probability for an electron to undergo collision or de-
flection per unit time. This energy is transferred to the lattice; on the
asgumption that all of it is spent in disruption of the lattice, one has
(e2E82/m) 7(w)At = U, where U = lattice energy, and the time At of the duration
of the breakdown is of the order of 10-8gec. If 1 were independent of E, one
should have proportionality between EZ and U. Data for alkali halides, RbI,
KI, RbBr, RbCl, Nal, KCl, NaBr, NaCl, KF, NaF, LiF (in the order of increasing
~ U) do not bear it out. More nearly, there is a linear relation between E and
U (with the points for KBr, Nal, and NaBr deviating considerably from the
straight line). Linearity between E and U means that T is inversely propor-
tional to E. If the dissocn. energy is used instead of U, i.e., if it is
assumed that elec. breakdown is accompanied by dissocn. into neutral atoms
rather than into ions, no linear relation is obtained. Consequently, elec.
breakdown corresponds to dissocn. of the lattice into ions. Over the time
interval T , the energy accumulated by the electron, Aw = (e2E2/m)T 2(w), and
the exptl. data lead to the conclusion that 7 is inversely proportional to
EY2 | “Tne decrease of 4 with increasing E holds only at sufficiently high E,
possibly when the kinetic energy of the electrons becomes comparable with the
vibration energy of the lattice points.

CA 46, 43054

-Growth of Alkeli Halides from the Vapor on Single-
Crystal Substrates of Alkali Halides

L. G. Schulz (Univ. of Chicago)

Acta Cryst. 5, 130-2 (1952)

Alkali halides of the NaCl-type structure (LiF, NaF, LiCl, KF, NaCl, NaBr,
KCl, KBr, KI, and RbI) were deposited from the vapor phase by evapn.-in a
vacuum onto cleavage surfaces of LiF, NaCl, KCl, and KBr. It was found by
electron diffraction that the crystals of the initial deposit were oriented
with their crystallographic axes parallel to those of the substrate for all
deposit-substrate combinations. Through the examn. of deposits that had an
av. thickness of only a few at. layers, the mechanism of crystn. of the
initial deposit was detd.
CA 46, 4871n

The Halides of Niobium and Tantalum. III. The Vapor Pressures of
Niobium and Tantalum Pentafluorides

Fred Fairbrother and Wm. C. Frith (Univ. Manchester, Engl.)

J. Chem. Soc. 1951, 3051-6; cf. CA Lk, 2879f

The wvapor pressures of NbF5 and TaF- were measured by a static method
using a Bourdon-type sickle gage and by g,p. detns. under g no. of controlled
pressures. Measurements near the b.p. were made in an app. in which the
whole interior of the gage chamber and sickle were plated with a thin film

of Ni deposited by thermally decompg. Ni(CO)u in order to eliminate reactions
of MF5 and traces of moisture with the glass. NbFg, m. 80.0°, b. 234.9°,
DHyen + 12.9 keal, log pgm = 8.439 - 2.824 /T, TaFs m. 95.1, b. 229.2°, AH .,

13.0 keal, log Py, = 8.524 - 2,834/T. Trouton's const. TaFs 25.9, NbFg 25.k.
A mixt. of the fluorides prepd. directly by fluorination of com. ferrocolumbium
is an excellent Friedel-Crafts-type catalyst.

CA 46, 48T75¢

Growth of Alkali Halide Crystals from the Vapor Phase and from Solution
Onto Substrates of Mica

L. G. Schulz (Univ. of Chicago)

Acte Cryst. &3 483-6 (1951) (in English); cf. CA 45, 5989

Electron-diffraction patterns were taken in 2 positions differing by
30° in the same app. in which the films were formed by deposition from vapor
onto muscovite cleavage surfaces. - KF, NaCl, NaBr, KCl, Nal, KBr, KI, NH.I,
and Rbl are oriented to the larger at. network in mica. LiCl with & mis-
match of 30% and NaF showed a (111) fiber structure; the latter showed con-
siderable diln. with crystals having random orientation. LiF was unique in
orienting to the smaller hexagonal mica network. Salts, such as RbI with
&, greater than 5.32A., showed a double-positioned type of angular orienta-
tion when grown from the vapor phase but only a single-positioned orienta-
tion when grown from soln. Crystal growth from soln. was studied by expos-
ing the salt deposited on the mica to moist air and evapg. Ho0 after return-
ing it to the camera. The growth of salts with a, 1less  than 6.5A. sup-
ported the oriented nuclcus hypethesis, whereas thé growth of salts with
ap zreater thaa 6.5A. supported the monoleyer hypothesis. Successive
deposits of different alkali haglides yielded films having the same orienta-
tions as the first salt .deposited. A deposit of KBr thicker than about
0.5A. was sufficient to cause.deposited LiF to have the same angular
orientation ag the KBr, A film.of MgFs, amorphous and nonporous, and about
0.5A. thick was sufficient to upset the.orientation of deposits. Close
at. matching at the interface was not required for an oriented overgrowth.
9
CA 46, Lok6f

Forms of the Complex Fluoroaluminates in Aqueous Solutions

G. S. Savchenko and I. V. Tananaev (N. S. Kurnakov Inst. Gen. Inorg. Chem. Acad
Sci. U.S.S8.R., (Moscow)

Zhur. Obshchei Khim (J. Gen. Chem.) 21, 2235-45 (1951)

By potentiometric measurements with a quinhydrone electrode, the varia-
tion of the pH in the binary solns. Al(N05)5 + H2C5 HF + Heo, and NHO3 + H20
with the concn. of the electrolyte is almost linear, In the ternary systems,
AL(NOz)5 + HNO + Hy0 and HNO3 + HF + H70, at const. sum A1(NOs), + HNO3 or
HNO5 + gF M, the variation of the pH is almost linear in the ratio
HNO Al(NO ) or HNOz:HF, resp., i.e., is detd. solely by the content of

, there ;s no indication of an interaction between either A1(NOx)xz and
HNO or HF and HNOz. 1In the system AL(NO ) + HF + Hy0, at the con&t: concn.
sumd A1(NOz)z + HF = 0.01, 0.03, and 0.1 3 the pH passes through a ‘max.
lying, in 811 3 cases, at the ratio HF: Al(NO )z = 2. Inasmuch as increase
of the acidity is due only to HNOg, it must De concluded that, at higher - ratios
HF:HNOz, there is a displacement of NO3z™ ions by F~ ious, i.e., at the max., &
reactidn AL(NOz)z + 2HF-—9A1F2NO + 2HNOz, or ALttt + 2HF-—AIF,* + ont. .
The same general plcture oung in tne systems A1Clx + HF + H0 and
A1,(80y )3 + HF + H50; in all cases, there is an undissocd. ion A1F2 . The
amt. of 3230 dlsplaced, and the degree of progress of the formation of the
AIF,** jon, can be detd. with the aid of data of the variation of the pH with
the concn. in the system H,S0) + Ho0. By thermal measurements of the temp.
rise At on mixing, as a function of the ratio HF:Al, in the systems A1(NOz)
+ HF + Ho0, and AlClz + HF + HO the heat evolved increases with the relat ve
amt, of HF in the sofn., and passes through a max. at the ratio AL:HF =
in agreement with the pH measurements; the temp. rise At can attain 1°.

These results again reveal the formation of A1F2 . There is no indication

of the presence of AlFz, or of more highly coordinated iomns. Nor is there,
at the coéoncus. used. ahy 1ndication of an ion AlF**, there being no singu-
larity at the ratio HF:Al = 1. In the light of these conclusions, the soln.
of ecryolite in Al salt solns. should be explained by formation of AlF," ions,
3NaF.AlF= + 2Alt+t —3A1F,* + 3Na*. Contrary to Brosset (CA 3T, 15-@),
the easy soln. of CaF, in AlCl solns. should be attributed not to formation
of A1F6 - ions, but to the reaction CaF, + ALttt —AlF, e Ca++, and the
analogous reaction with Be** ions should be formulated CaF2,+ 2Bett —2BeF*t
+ Cat*, It is incorrect to explain the difficulty of the decompn. of cryo-
lite by evapn. with H,S0), by a stability of AlFg™~~ ions; actually 2/3 of
the total F in cryolite are split off very easily, AlFs"' + kH+—-—9AlF2 +
LHF, and only the remaining 1/5 is difficult, and requires twice-repeated
evapn. to dryness.
10
CA 46, 49861

Separation of Iron and Nickel from Fluorides
Melvin A. Perkins and Monroe Couper (to U.S.A., represented by A.E.C.)
v.s. 2,588,041, Mar. 4, 1952

. Sludge produced in making F by electrolysis of KF.2HF is treated with
an equal wt. of Ho0, filtered, the filter cake agitated with 23% NH)O0H for
3 hrs, filtered and washed. The filtrate is evapd. 15-20% to produce NiF,,
and then to dryness producing K and NH), fluorides.

CA 46, 5276a

Alkali Aluminum Fluoride .
Erling Brodal and Henning Guldhav (Aktieselskapet Norsk Aluminium Co.)
U.S. 2,592,113, Apr. 8, 1952

See Brit. 621,569 (CA 43, 7201b)
CA 46, 5278a

Sodium Aluminum Fluoride
Kenjiro Yamamoto (to Nippon Light Metals Co.)
Japan. 180,937, Nov. 15, 1949

To 320 g of an impure HF contg. 19% HF and 3% SiF), is added 56 g (AL(OH)
contg. 55% Aly0z to make ALF,(OH), then there is added 24 1. sea water (treate
with 10 g NaOH per 3 1. and filtered to remove Mg(OH)E)h The ppt. is allowed
to settle, the clear upper layer is removed by decanting, and the ppt. is
washed with water and heated at 500° to yield 90 g 5 NaF,EAlFB.

CA 46, 5795h

Aluminum Fluoride
National Smelting Co., Ltd., and Arnold J. Edwards
Brit. 656,374, Aug. 22, 1951

AlF., is prepd. by passing gaseous HF upward through & fluidized bed of
particleg of Al,0z and A1(OH)z at 350-650°, the heat required for raising
the temp. being olly.deriveg from the reaction itself if the mixt. contains
a major portion of Al,0z. When a considerable proportion of Al(OH)3 is
present, addnl. heat is supplied by burning fuel. The reaction may be
performed batchwise; but preferably is conducted in two or more stages.

The beds of the aluminous material are superimposed, and the gas is passed
in series up through them, while the aluminous material overflows from each
bed to the one below.
11
CA 46, 57971

- Sodium Fluoride
Edward A Heisler (to Allied Chemical and Dye Corp.)
U.S. 2, 585,387, Feb. 12, 1952

NaSiFg slurry, which may be a by-product from fertilizer manuf., is
treated in a continuous manner with Na,COz while withdrawing a reaction mixt.
of Si(OH)4 and cryst. NaF. This mixt. is sent to a classifier, The small
crystals are returned to the first reactor while the larger crystals and the
Si(OH)u,go to & second reactor where NaOH is added to neutralize the acid.
NaF crystals and NagSiO3 soln. are recovered from the second reactor.

CA 46, 6450n

Dielectrics with a High Dielectric Strength
E. K. Zavadovskaya ,
Doklady Akad. Nauk 8.S.S.R. 82, 709-12 (1952); cf. ibid. 8L 375 (1951)

The previously established formula for the dielec. strength of solid
dielectrics of the NaCl type, Eg = ((7.683 (a + b)/(Ry + Rg))wywg) - 3.9,
expresses a relation between the close-packing of the lattice, character-
ized by the factor in ( ), and the valence bond, characterized by the factor
wpwpe Calcns. by this formula of Eg for LiF, NaF, KF, LiCl, NaCl, KCl,

_ RbC§, NaBr, KBr, RbBr, LiI, Nal, KI, RbI, MgO, CaO, BaO, and FeQ are in
good agreement with data of lattice enmergies. Fluorides, oxides, sulfides,
and carbides can be expected to have a high E4, except for certain impurity-
semiconductor oxides such as Cus0, Cd0, Ago0, MoO,, or SnO, which have high

latiice energies but low E;. This insonsistency is probably due to pos.
‘type of elec. cond. and the impurity-conductor nature of these oxides; with
increasing field strength, the cond. increases rapidly and breakdown occurs
at relatively low field strengths. High polarizability also favors loss of
elec. strength; this may lead to a low Eg, despite a high lattice energy,
particularly in sulfides and selenides. In solids the first stage always
consists in a perturbation of the elec. strength through liberation of
electrons; the second stage is the breakdown of the lattice proper. The
first stage is easiest in sulfides, then in oxides, and then in fluorides.
In gases the breakdown consists wholly in the first stage.

CA 46, 6470Db

Cryoscopy in Molten Lithium Borate.  pryoscopy of Fluorides

Georges Zarzycki
Compt. rend. 234, 1370-1 (1952); cf. CA 46, 337lb

nyoscopic detns. of LiF, NaF, KF, BeF,, MgF,, CaFp, SrF,, BaF,, ZnFp,
CdF,, PoF,, and AlFz in molten LiBO, showed that all were completely ionized.
Natural cryolite, Na5A1F6, was ionized into particles, i.e., did not form

A1F65- complexes.
CA 46, 6516f

Cryoscopy in Fused Cryolite and Ionic Constitution of Dissolved Aluminum
Masurice Rolin
Bull. soc. franc. elec. 2, 35-56 (1952)

The mechanism of Al electrolysis was investigated to define the phys.-
chem. constitution of Al solns. in fused cryolite. The mol. state of the
fused cryolite and the dissolved Al are represented by: Na g —AlFz + 3F
+ 3Na*, and A1503—A105” + 07" + A1Y*,  The fundamental flechanism of the
Al electrolysis can be said to be g direct discharge of its ions and the
discharge of the Ha* lons to be only a secondary and parasitic phenomenon.
The normal course of the electrolysis is thus defined as that in which only
the Al ions are discharged, and the cryolite, though ionized, does not
participate in the electrolysis. A 3-part diagram represents the mechanism
of the electrolysis, showing in the first part the ionization of the non-
electrolyzed cryolite, in the second the discharge of the Al ions, and in
the third the case of eventual formation of A10Y ions, from which the libera-
tion of Al atoms proceeds by the transfer of electrons.

CA 46, 6883

Magnetochemistry of the Heaviest Elements. V. Uranium Tetrafluoride-
Thorium Tetrafluoride Solid Solutions

J. K. Dawson (At. Energy Research Establishment, Harwell, Berks, Engl.)
J. Chem. Soc. 1952, 1185-6; cf. CA 46, 2863h

Owing to an arithmetical error, the concns. of U in the solid solns.
previously reported were wrong. Corrected values for the susceptibilities
and magnetic moments of the U(IV) ion are given that differ considerably
from the previous values. The susceptibility at room temp. and the moment
extrapolatéd to infinite diln. now agree within exptl. error with the val-
ues predicted for 2 unpaired spins with the orbital contribution to the
moment completely quenched (X = 5555x10“6,/a-m 2.83). These values imply
a 6d° electron configuration for the uranous ion, rather than the 5f
arrangement indicated by the values first reported. This agrees with the
configuration indicated by the earlier work on urania-thoris solid solns.

CA 46, 6919n

The System Ammonium Fluoride-Sodium Fluoride-Water at 25°
Helmut M. Haendler and Avis Clow (Univ. of New Hampshire, Durham)
J. Am. Chem. Soc. Th, 18+3 (1952)

Schreinemakers' wet-residue method (CA 40, 53%28-8) was used in the
study. Chem. and x-ray analyses established the compn. of the phases.
No double salts are formed, and NHLF and NaF are the only solid phases.
There is no evidence for the existence of hydrated NaF in the equil. mixt.
15
CA L6, 7&051

Cryoscopic Study of Solutions of Certain Metallic Oxides in
The Butectic Cryolite-Sodium Fluoride

Georges Petit

Compt. rend. 234, 1281-3 (1952)

Cryolite and the eutectic cryolite-NaF contain, resp., 25% and 14 mol %
AlF., and m. at 1008° and 885°, resp. The eutectic is an excellent solvent
on account of nonvolatility and const, m.p. Its cryoscopic const. is only
27, as compared with 41 for cryolite. Results at the 2 temps., are plotted
and discussed for La205, ThOo, A1203, CeO,, Ca0 and 3203.

CA 46, TWléi

Fusion Diagrams of the Ternary Systems of the Fluorides

of Lithium, Sodium, Potassium and Rubidium

E. P. Dergunov

Doklady Akad. Nauk S.S.S.R. 58, 1369-72 (1947); Chem. Zrntr. (Russian Zone
Ed.) 1949, I, 655; cf. CA 45, Olhlks

The fusion diagrams of the alkali fluorides have theoretical interest
because of the formation of solid solns. and eutectics showing large m.p.
reductions. For the binary system LiF-RbF the m.p. lowering from the lowest-
melting component (Rb, 780°) to the eutectic is 330°, The m.p. lowering for
the ternary system LiF-NaF-RbF is only slightly greater (354°). The explan-
ation for the fact that the m.p. lowering is only slightly greater in the
ternary system is probably that the tightest possible packing has already
been reached in the binary system. The properties of the individual alkali
fluorides and the 6 possible ternary systems are reviewed. In the termary
system LiF-KF-RbF, the crystn. curve goes as a straight line from the LiF-
RbF side to the LiF-KF side of the LiF-KF-RbF triangular fusion diagram
(m.p. 450-492°; crystn. Zone: the solid soln. T5. u%, LiF 24.6%). 1In the
system NaF-KF-RbF, the crystn. curve shows a min. in the neighborhood of
the NaF-RbF side (m.p. 644-710°; crystn. zone: solid soln. 55.6%; NaF
Wi 4%). In contrast to these 2 systems, the system LiF-NaF-RbF shows 3
crystn. zones (NeF 59.4, LiF 21.1, RbF 19.5%). The ternary eutectic point
is at 426°; NaF 6.5, LiF 46.5, RbF 47 mol %. -

CA 46, ThlTf

Liquid-Solid EqQuilibria in the Quaternary System Containing NaCl, KCl, CaCl,,
NaF, KF, and CeFp. (The three corresponding reciprocal ternary systems, the
system containing three fluorides, and the binary system containing KF and
CaF5)

Mohammad Ishaque (Faculte sci., Paris)

Bull. soc. chim. France 1952, 127-38

Coaling curves were used to det. equil, diagrams for the various systems.
Twelve solid phases were found, consisting of the 6 simple salts; 3 double
salts, 2KCl.3CaCl,» CaClp.CaFo, and KF.CaFp; 1 series of mixed crystals, without
1k

a miscibility gap, in the system NaCl and KCl; and 2 series of mixed crystals,
with a miscibility gap, within the system NaF and KF. Twelve ternary invar-
iant points of three kinds were found: (1) eutectic, (2) peritectic, and
(3) a ternary min. where the invariance is due to the fact that the solid
and liquid phases keep the same compn. Eight different types of diagrams
showing the following solid phases were found; (1) NaCl, NaF, and CaF,,

(2) KC1, CaFp, and 2KC1.CaCl, (congruent f£.p.), (3) KCl, CaF,, and KF.CaF
(congruent f.p.), (4) NaCl, CaClp, CaF,, and CaCly.CaF, (incongruent f.pei,
(5) CaCl,, CaF,, 2KCl.3CaCl, (congruent f.p.), and CaCl,.CaF2(incongruent
f.p.), (g) KCl and two series of mixed crystals contg. NaF and KF, (7) CaFs,
KF.CaF- (congruent f.p.), and 2 series of mixed crystals contg. NaF and KF,
and (8) NeF and 1 series of mixed crystals contg. NaCl and KCl.

?

CA L6, 7h184

Thermodynamics of Beta-KHF,, Including Heats of Dissociation,

of Fusion, and of the Alpha-Beta Transition

Merton L. Davis (Univ. of Michigan, Ann Arbor)

Univ. Microfilms (Ann Arbor, Mich.), Pub. No. 3487, 177 pp. (Microfilm g2.21,
Paper enlargements $17.70); Dissertation Abstracts (formerly Microfilm
Abstracts) 12, 130-1 (1952)

CA 46, Thhoi

Hydroxytrifluorcborates
I. G. Ryss and M. M. Slutskaya (Dnepropetrovsk Met. Inst.)
Zhur. Obschchei Khim. (J. Gen. Chem.) 22, 41-8 (1952)

(1) KHF,, 0.1 mole, was added to 4.1 g soln. contg. 0.1 mole HF, the
soln. was cooled to 0°, and 0.1 mole HzBOz was added with stirring. The
yield of KBF-OH was 11.6 g. The salt can”be recrystd., contrary to the
statement of Wamser (CA 42, 4430i)., It is insocl. in, and is not decompd.
by, EtOH or Iso-AmOH. (2) NaBF:OH cannot be prepd. by this method with an
adequate yield and sufficiently pure. To obtain better products, mix aq.
NaHF,,:HzBOz = 2:1 moles at 0°, with 50-100 ml H,0 per mole H3BOz. Evap.
the %il rafe from the small amt. of NaF in vacuoc or ppt. with a 4-fold vol.
of EtOH. Mean yields are about 50% of the theory. NaBFzOH is easily sol.
in Ho0, very little sol. (0.3%) in EtOH, and is not decolipd. by the latter.
This compd. is very different from the alleged NaOH.BF: described by Meer-
wein and Pannwitz (CA 29, 1060-1). (3) On standing, the acidity of aq.
KBFz0H solns. decreases., The decompn. can be 3BFzOHZ=2BF)” + HzBOz + F~(I)

Fz0H™ & BF5(0H)2 + BF,,"(II). The equil. yield of BF), ~ inCreases
slightly with the diln., particularly in the concn. range 0.33-0.11"M;
this is taken to indicate a prevalence of the process I. The yield of
BF),~ also increases slightly with the temp. The calcd. heat of reaction I
is 4.2 kcal.; for II, the calecd. heat of the reaction is less than 1.k kcal.
The order of the formation of BF)~ is somewhat lower than first. (4) The
soly. of KBFzOH in H,0 cannot be detd. with accuracy on account of the slow
decompn. of the solus.
15
CA 46, T86ke

Physicochemical Analysis of Ternary Aqueous Systems of Fluorides of Alkaline
Barth Metals and Alkali Metals. I. Ternary Systems BaFo-KF-H-0 and BaFg-NaE-Hé)
Sh. T. Talipov and V. A. Khadeev (Central Asian State Univ., Tashkent)

Zhur. Obshghei Khim. (J. Gen. Chem.) 20, T74-82 (1950); J. Gen. Chem. U.S.8.R.
20, 813-21 (Engl. translation).

The ternary systems were investigated by analyzing satd. solns. and wet
residues according to the Schreinemakers method, all at 25°. No double salts
or solid solns. are formed in either system. The soly. of BaF, in KF and in
NaF was detd. at concns. of alkali fluoride up to 0.5 M. The exptl. results
agree well with those predicted by the Debye-Huckel theory in its second approx
imation.. Values for KF concn. (M) and for the soly. of PoF, (M) are, resp.:
0.0, 9.23x10~2, 1.087x10"2, 6.20x10"2; 5.011x107=, 1.50xlo-§; 0.1001, T.5x1074;
0.5020, 2.2x10"", The values obtained for the soly. of PbFo in NaF are similarn

II. Ternary systems SrF,-KF-H,0 and SrFp-NaF-E 0. Ibid. 763-8.

No double salts or solid solns.- are formed in either system, the diagrams
being qualitatively identical with those for the corresponding Ba compds.
Soly. of SrF, was studied at concns. of NaF and KF up to 0.0l M. Values of
NaF conep. (M) and SrF, soly. (%) are, resp.: 0.00, 9.62x1077, 1.935):10'5,
4.51x10-%; 3.990x10-5, 2.00x10~"; 6.982x10“3, 9.3x10-2; 1.096 x107<, 5.Ox.].0'5..
Data obtained with KF are similar.

CA 46, T923f

The Influence of the Cation Radius on the Energy of Formation of Addition
Compounds. III. The Systems Alkali Fluoride-Alkali Chromate, Molybdate, and
Tungstate ‘
O.-Schmitz~Dumont and Albert Weeg (Univ. Bonn, Ger.)

Z. anorg. u. allgem. Chem. 265, 139-55 (1951); cf. CA 4k, 3829f

~ The systems MF-MCrO), MF-MpMoO), and MF-M WO, (M = alkali metal) were
investigated thermally and by x-ray analysis. NaF-NaosCrQ), LiF-LijMoO) and
LiF-LioWO0) have simple eutectics and form no compds. In all other systems
& compd. of the compn. MsZOyFexists (Z = Cr, Mo, or W). NazMoOLF and NazWOLF
melt incongruently. All others melt congruently. The energy of complex for-
‘mation (MoOy~~ + F~ =(MoO\F)~"") is negative. X-ray analysis of the fluoro-

chromates, %luoromolybdates , and fluorotungstates show that they can be sepd.
into 4 groups which contain salts isotypical with one another: (1) NazMoOuF,
NazWOLF; (2) all fluorochromates; (3) KzMoOLF, K3WOLF;RbzWO,F; (4) RbzMoO)F,
CszMoQ)F, CszWO)LF.
IV, The Sysééms‘Alkali Fluoride-Molybdenum (VI) Oxide
0. Schmitz-Dumont and Irmgard Heckman, Ibid, 267, 277-92 (1952)

Congruently melting M3M003F3 occurs in the systems with KF, RbF, and CsF.
In the system NaF-MoO-j ) Na3M005F3 melts incongruently. L15M00§F5 does not
exist. The energy of complex formation of the compds. is positive. The
compds. crystallize in the cubic system, and hydrolyze in damp air to M3M001,,F.
16'
CA 46, T924e

Double Fluorides of Uranium Hexafluoride
H. Martin. A. Albers, and H. P. Dust (Univ. Kiel, Ger.)
Z. anorg. u. allgem. Chem. 265, 128-38 (1951); cf. CA 43, 61024

UFg (free from HF) forms fluouranates (VI) with AgF and the alkali
fluorides (except LiF) at temps. below 100°. Double salts of definite compn.
are obtained: 3AgF.UFg, BNaF,UFg (citron yellow), 3KF.2UFg (gold yellow),
2RbF.UFg (citron yellow). All the compds. hydrolyze immediately with H0.
At temps. above 100°, the Na and K salts give off F along with UFg to form
colorless fluouranates (V).

CA 46, 8435c

Magnetochemistry of the Heaviest Elements. VI. Plutonium Dioxide-

Thorium Dioxide and Plutonium Tetrafluoride-Thorium Tetrafluoride Solid Solutions
J. K. Dawson (At. Energy Research Establishment, Harwell, Engl.)

J. Chem. Soc. 1952, 1882-6; cf. CA 46, 2863h, 688%b

Solid solns. of Pth-ThFu and PuO,-ThO, were prepd. from very pure
meterials,-with the concn. of Pu varying from 100% to 2%, X-ray diffraction
studies indicated the formation of true solid solns. The magnetic suscepti-
bilities of most of these were measured at a no. of temps. from 90° to about
450°K., by the microbalance method (cf. CA 45, 3669h), but for low concns.
only values at 300°K are given. To obtain the true paramagnetism of the
Pu(IV) ion corrections for the diamagnetism of the various ions were applied.
The tabulated results give X, (gram susceptibility, J(m (Molar susceptibility)
and X (gram-ion suscep%ibility corrected for diamagnetism). Above
200°K PuF), Obeys the Curie-Weiss law, but the (1/X)-T line curves up some-
what below 200°K. Extrapolation to infinite diln. of the PuF) values at
300° indicates that the susceptibility of Pu(IV) is approx. 3020x10~°, which
is in reasonable agreement with that calecd. for a 5f" electron configuration
with L-S coupling. The susceptibility of PuO, is considerably lower than
that of PuF) and does not obey the Curie-Weiss law. The results for ThO,
indicate a very rapid increase in X py(Iv) between 10 at. % and infinite
diln., and the value at infinite diln. is about the value for a 5fu config~
uration, although there is some evidence that 6d levels are occupied. The
methods of prepn. and testing for purity are outlined.

CA 46, 84ghe

Properties of Solutions of Beryllium Fluoride.III.
I. V. Tananaev and E. N. Deichman
Izvest. Akad. Nauk S.S.S.R., Otdel. Khim. Nauk 1951, 26-31; cf. CA 43, 604Sh

The systems BeF,-H 0, Be(NO3)2-H20, and Bng—Be(NO5)2»H20 were studied
by investigating » and d. at 25® and f.p. at salt concns. up to 2 M. 1In all
cases 7 and d. increase and the f.p. decreases with increasing salt concn.
In the system BeFp-H0, values for BeF, concn. (M), 7 x 102 (25°), and f.p.
L7

are, resp.: 0.0, 8.85, 1.0108, 0.0; 0.4, 10.00, 1.0115, -1.6°; 1.0, 11.77,
1.0353, =k.2°; 1.4, 13.14, 1.0375, -6.9°; 2.0, 15.68, 1.0699, -10.3°. The
corresponding values for Be(NO )2 solns. are: O.4%, 10.17, 1.0302, -0.2°;
0.8, 11.61, 1.0590, -1.00°; 1.2, 14.56, 1.4563%, =-2.00°; 2.0, 17.71, 1.7708,
-3.0°., The f.p.-concn. curves in the BeFo-H,0 system are composed of two
straight-line portions intersecting at about l.1 M BeF,, but in the system
Be(HOB)g-H2O the f.pe. decreases smoothly with increasing concn. In the
ternary system BeF,-Be (wo )2—H20 » values for 77 and d. at 25° and for f.p.
were obtained at ratios 03 Bng/Be(NO )2 from 0.1 to 3.0 using a total concn.
of BeF, + Be(NO3), = 2.0 M. Values fOr BeFp/Be(NOs), ratio, n x102 (25°),

d. (25°), and fip. are, resp.: 0.2, 17.11, 1.1330, -5.5°; 0.6, 16.61, 1.1179,
-6.0°; 1.0, 16.21, 1.1061, =-7.2°; 1.2, 16.17, 1.1030, =-7.4°; 1.6, 16.00,
1.0985, -7.8°; 2.0, 16.13, 1.0957, -8.1°. The curves of BeF,/Be(N0z), ratio
against » and against f.p. show a sharp break at a ratio of 1.0. This is
interpreted as an indication of the formation of the ion BeFt+ by the reac-
tion BeF, + Bett = OBeF*, existence of the ion having been indicated by
previous work.

CA 46, 8557g

Solubility of Magnesium Fluoride in Solid Lithium Fluoride
Y. Haven
Rec. trav. chim. 69, 1505-18 (1950)

By using exptl. values detd. previously for the ionic cond. of LiF-MgFo
mixed crystals (CA 45, 4111h) the soly. of MgF» in solid LiF is caled. as
0.04-k4,6 mol. % over the temp. range 400-700°. The energy of soln. of
MgCl, in LiCl, MgFo in LiF, and Liy0 in LiF is also calcd., and the data are
discussed in relation to Goldschmidt's theory of formation of mixed ionic
crystals. In addn. to the necessary similarity in ioniec r, the gain in
polarization energy on soln. of the solute is also an important criterion
for formation of mixed crystals, particularly in cases where the solute
contains ions having & valency different from that of the solvent iomns.

This gain in energy is necessary to compensate the loss of Madelung energy
on soln. of the solute, and is provided by polarization of the solvent
lattice consequent on the charged lattice defects arising from the differ-
ently charged solute ions.

CA 46, 8598b

Corrosion by.Fluorine and Fluorine Compounds
Ralph Landau (Scientific Design Co., New York, N.Y.)
Corrosion 8, 283-8 (1952)

The extreme reactivity of F is coupled with the high resistance of F
compds. to chem. attack, as it tends to displace other elements and no
other element is sufficiently reactive to displace F. While F is near O
and Cl in the periodic table, its-2.85 v. electronegativity is the highest
known so F tends to displace O and Cl from their compds. The heat of
reaction of F is much greater than for O and Cl and while metals that
18

resist oxidation may also resist F, contaminants,especially org. materials,
may react so rapidly as to initiate ignition of backing metal. Ni and Monel
are resistant in clean systems; Cu, Al, and Mg are less resistant but may

be used for special purposes. In the presence of moisture, when HF is formed,
Monel has better resistance than Ni. Teflon or Al 25 disks should be used in
valves seating on Monel. General characterigtics of the fluorocarbons are
given and some specific fluorocarbon materiasls are described. Safety pre-
ceautions in handling F are discussed.

CA 46, 8819a

Sodium Bifluoride
Ernest A. Winter (to Tenn. Corp.)
U.s. 2,602,726, July 8, 1952

NaHF, is produced from H-SiFg by treating the HoSiFg first with NaF
to form HF and NasSiFg, which latter is filtered off, dried, and calcined,
The SiF) formed may be recycled to conc. the H,SiFg before treatment, and
the NaF is recycled to ppt. more Na,SiFg. The HF formed above is conecd.,
and mixed with NeF to ppt. NaHF,, which is filtered and dried. In this
way NaHFo, may be made from such cheap materials as the waste gases from
superphosphate manuf.

CA 46, 9270g

Zirconium Tetrafluoride
Harley A. Wilhelm and Kenneth A. Walsh (to U.S.A., A.E.C.)
U.8. 2,602,725, July 8, 1952

A nonhygroscopic ZrFy is produced by treating ZrCl) with anhyd. HF at
50° until at least 90% conversion has occurred and then continuing to com-
pletion of the reaction at 300°. The product does not fume in moist air.
By employing a complex of ZrCly, with POClz, all of the HF contamination
may be removed by distn. If a product of higher d. is desired, it may be
obtained by subliming the original product at 800°,

CA 46, 9356h

The Magnetic Behavior of Nonmetallic Solid Substances
J. H. van Santen (N. V. Philips Gloeilampenfabrieken, Eindhoven, Netherlands)
Chem. Zentr. 1950, I, 1823

A summary on the magnetic behavior of nonmetallic substances, including
discussion of the causes of at. dia- and paramagnetism, the Curie-Weiss law,
the orbital moment and the spin moment of the individual atom, counter
effects on the atom, and exchange forces as the cause of ferro- and anti-
ferromegnetism. The ions of the rare earths and the ions of the elements of
the Fe group are considered. Agreement is not so good for the latter group;
the measured magneton value corresponds only to the electron spin. Compds.
19

considered are: K:Mn(CN)g, KsFe(CN)g (good agreement), K)Fe(CN)g, K3Co(CN)g,
KoNi(CN)), (moment”0), Fe?NH5 £CLo, Fe(N53)6c15, Co(NH3)6C1p, Co(NH§)6c;3,
K3CoF6,_Co(NH3)§F5 (diamagneétic), CrCl5, MnCl,, FeCl,, FeClx, Cr203 (moment
if agreement with the velue for the eléctron spin only), Mng (same”as pre-
ceding), Mny03, FeO, Co0, NiO (antiferromagnetic, Fez0), (ferromagnetic),
TiOp, Cr03, MiS (antiferromagnetic), and the systems Cr-S and Fe-§ (ferro-
magnetic within the intervals CrS3,10-1,18 and Fesl,og-l,lh)a The signifi-

cance of magnetic measurements for the‘explanation of the structure of chem.
compds. is discussed, with K-BoHg, HoS50), and HgoCl, being used as examples.

CA 46, 9965a

A Criterion of the Electrolytic Dissociation of Fused Salts
Genevieve Sutra

Compt. rend. 234, 1283-4 (1952); cf. CA 46, 335T7h

~ The idea is developed that when an ion is formed by fusion of a salt
the entropy (of fusion) should be about 3/2 R or 3 cal. About this value
is found for the noble gases, HCl and HI. Heat of fusion, with temp. and.
entropy are given for NaCl, NaF, KCl, T1Cl, AgCl, AgNO5, NaNO- and KNOx.
These entropies are usually nearly twice those for one”ion, for there are
two ions here. Some salts, as KNOz, show a lower value, perhaps owing to
incomplete ionigzation. Data are aiso given for CaCl,, BaCly, PbCl,, Pbly,
Hglo, and K-Cr,0-. Total dissocn. should give about 9 cal. for the entropy,
but most values shown are considerably below this figure. The . dichromate
gave a higher value, attributed to dissocn, of the dichromate ion. Sim-
ilar data are given for cryolite and LiBO,. The former appears to yield
4 ions, the latter more than 2, owing, perhaps, to a dissocn. of the borate
ion (cf. Zarzycki, CA 46, 3371b). " E ~

CA 46, 10022i

Electrolysis of Fused Salts
A. J. Rudge, H. Hill, W. N. Howell, and Imperial Chemical Industries, Ltd.
Brit. 675,209, July 9, 1952

An. app. is described for the production of F by the electrolysis of
a wmixt. of HF and an alkali metal fluoride. No diaphragm is used in the
app. because constructional features, such as the placement of the electrodes,
prevent mixing of evolved F with the H produced at the cathode. The F rises
along the vertical surfaces of the C anode. |

CA 46, 107121

Broader Regularity in the Periodic System.
D. Balarev and St. Andreev.
Annuaire univ. Sofia. II, Fac. sci., Livre 2, 46, 159-75 (1950)

Available data on the phys. properties of oxides, and the oxide-
formation power of the elements of the principal groups and the subgroups
are reviewed. It is found that the sp. grs. of oxides and the heats of
formation of the higher oxides, chlorides, sulfides, fluorides, bromides,
and iodides show period regularities.
20
CA 46, 10718

Bond Strengths in Boron Trifluoride and the Tetrafluoroborate Ion
J. Boubeau and W. Bues {Univ. Gottingen, Ger.)
Z. anorg. u. allgem. Chem. 268, 221-8 (1952)

The B-F bond strengths were calcd. to be 6.86 x 107 dynes/cm in BF_and
5.278_x 102 dynes/cm in BF),~ from the ultraviolet and Raman spectra of BIOF
and BLF. (Gage and Barker, CA 3%, 6717-4; Yost, et al., CA 32, T34k-5; Bailey,
et al., éA 31, 3784-5, 7755-6) and the Raman spectra of NaBF). The stronger
binding in‘BF5 is caused either by partial double bond character of the BF
bonds or by greater ionic character of the BF),~ bonds. The B-F bond distahces
in the 2 compds. and the relative B~C bond strengths in MejBNH3 and Me
(z. anorg. u. allgem. Chem. 268, 1 (1952)) support the first eXplanatidnm.

CA 46, 107k6e

Preparation and Physical Properties of Niobium Pentafluoride.

J. H. Junkins, R. L. Farrar, Jr., E. J. Barber, and H. A. Bernhardt (Union
Carbide and Carbon Corp., Oak Ridge, Tenn.).

J. Am. Chem. Soc. T4, 3464-6 (1952)

NbF- is prepd. by fluorinating Nb with elemental F at 300°. Analysis
of warmifg and cooling curves resulted in the estimates: m.p. 78.9 * 0.2°,
heat of fusion 8600 cal/mole. The vapor-pressure dats for purified liquid
NoF'; (10 to 1286 mm) are described by: log Py, = 8.3716 - 2779.3/T, where
T is temp., °K. From this equation the b.p. is estd. to be 233.3 * 0.5°.
From the heat of fusion and the vapor pressure of NbF5 at the m.p., the
following expression approximating the vapor pressure over the solid is
caled.s log Py = 14.397 - 4900/T. The vapor pressure at the triple point
is 3.0 mm., and the heat of sublimation is calcd. to be 22,400 cal/mole.
The liquid d (g/cc) measureg in the range 86-125° is given by: d. = 2.8026
- 9.81 x 10™% - 6.16 x 10-6t2, where t is temp., °C. Thermodynamic
quantities calcd. from the vapor-pressure data and corrected for deviation
from ideality by the d. measurements are: = =8.5 cal/degree-mole;

= 16,800 - 8.5 T; AS, = (16,800/T) - 8.5.” The compd. is more stable
toward hydrolysis than either Rqu or UFg. There is mno evidence of decompn.
of NbFg at temps. up to 255°.

CA 46, 10768g

The Crystal Structure of K TiFg.
Stanley Siegel (Argonne Natl. Lab., Chicago)
Acta Cryst. 5, 683-4 (1952)

K-TiFg is trigonal and the structure is of the K GeFg type. The unit
cell dimensions are a = 5.715 * 0.002, ¢ = 4.656 £ 0.001.A. Each Ti atom
is linked to 6 F atoms at the+fiorners of a distorted octahedron, with Ti-F
= 1,91 A. This leads to a Ti*" radius of 0.58 A. Each K is bonded to 12
F agoms, of which 6 are at a distance of 2.87 A., 3 at 2.75 A., and 3 at
5.00 A. |
CA 46, 108094

The kineties of the Acid and Alkaline Hydrolysis of Methyl Fluoride in Water
D. N. Glew and E. A. Moelwyn-Hughes (Univ. Cambridge, Engl.)
Proc. Roy. Soc. (London) A211, 254-65 (1952)

The kinetics of the reaction are studied experimentally. The influence
of additional solutes is studied by using HC1OL, KClOu, NaF, CH30H, HF, and
KBr. The reaction of methyl fluoride with hydroxyl ions is studied in detail.
Calcd. and experimental activation energies are compared for MeF, MeBr, Mel,

and-MeCl.
CA 46, 10838g

Thermodynamic Properties of the Fluorine Atom and Molecule and of Hydrogen
Fluoride to 5000°K.

Leland C. Cole, M. Farber, and G. W. Elverum, Jr. (California Inst. of
Technol., Pasadena)

J. Chem. Phys. 20, 586-90 (1952); cf. Butkow and Rozenbaum, CA 4%, 1OLTTi.

The evaluation of the thermodynamlc functions of the F atom and mol.
and HF from 100°K to 5000°K were made by statistical calcns. from available
spectral consts. for the atom and for HF; for F the consts. were derived or
estd. from the Raman shift in gaseous Fp, the equil. internuclear distance
from electron diffraction measurements, and the heat of dissocn. These re-
sults were combined with the thermodynamic functions of H, to evaluate the
heats and free energies of dissocn. and dissocn. consts. for the equilibria
Fp = 2F, HF = 1/2H, + 1/2F,, and HF = H + F.

CA 46, 1083%h

- The Effect of Cation Radius on the Energy of Formation of Addition Compounds.
V. The Systems Alkeli Dititanate - Alkali Fluoride

0. Schmitz-Dumont and A. Hildegard Schulz (Univ. Bonn, Ger.).

Monatsh. 83, 638-49 (1952); cf. CA 46, 7923g

The systems MF-MsTi 05, where M was K, Rb, or Cs, were studied by
means of thermal analy81s and x-rays. In the Rb and Cs systems there was
a8 congruently melting compd., 3M T1205 +MF, while there was none with K;
the Cs compd. decompd. at room temp. “As for previously investigated systems
(MFeM COz), the energy of formation increased with cation radius to a max.,
then decreased, although in the present case the anions do not exist sep-
arately in the lattice, and therefore the addn. compds. are not true complex
salts. Although Li,TiOz and NaoTiOz are definite compds., KoTiOz could not
be prepd. free from K T1505 and KO0 but x-rays showed its presence, the Rb
and Cs compds. behaved similarly.
22
CA 46, 10866¢

A Single-Crystal Neutron-Diffraction Determination of the Hydrogen
Position in Potassium Bifluoride.

8. W. Peterson and Henri A. Levy (0Oak Ridge Natl. Lab., Oak Ridge, Tenn.)
J. Chem. Phys. 20, TO4-T (1952); cf. CA 46, 2369e |

Neutron=-diffraction measuréements on KiF, single crystals show that the
H atom occupies the central position, within 0.1 A., in the linear F-H-F ion.
The data also indicate asymmetry in thermal motion, which suggests that the
HF,>"™ undergoes rotatory oscillation with apprecisble amplitude. The study
demonstrates the usefulness of single-crystal neutron-diffraction data for
crystal structure detn. |

CA 46, 1099%h

The Affinities of Chromic Ion and Gallium Ion for Fluoride Ion
Archie S. Wilson and Henry Taube (Univ. of Chicago)
J. Am. Chem. Soc. Tk, 3509-12 (1952)

The equil. existing in solns. contg. Cro*, HY, F~, and ClOy~ are studied
by a spectrophotometric method which utilizes the change in optical d. of a
soln. of Feo* when F~ is added. The quotients (CrF2+) (m‘)/Cr3+) (&F),
(cxFo*)(EY)/(CrFo*)-(HF), and (CrFz)(E*)/(CrFot)(HF) at 25° and ionic
strength 0.5 are estd. to be: 26.0; 2.5 (approx.), and 0.3 (approxéz, resp.
The e%uil. are established slowly. The hydrolysis quotient for Fe /",
(PeOH*) (H*)/(Fe>t), and the corresponding quotient for Ga * at 25° and
ionic strength 0.5 are: 1.6 x 10-3 and 1.2 x 10~2, resp. The quotient

(GaF=*) (&) /(Gad*) (iF) is 1.2( 0.2) x 10°.
CA 46, 109984a

The Reaction of Fluorine with Zinc, Nickel, and Some of their Binary
Compounds. - Some Properties of Zinc and Nickel Fluorides.

Helmut M. Haendler, Wm. L. Patterson, Jr., and Walter J, Bernard (Univ. of
New Hampshire, Durham)

J. Am Chem. Soc. Tk, 3167-8 (1952); Am. Doc. Inst. Doc. 3503 (film or photo-
print $L.00); cf. CA 46, 1837h

The reaction of F with Zn, Zn0O, ZnBrp, ZnS, Ni, NiO, Nip0z, and Nis is
investigated. 2ZnF, and NiF, are the only non-volatile products observed;
. the crystal structures of these fluorides are checked by x-ray diffraction.
Both are tetragonal; for ZnF,, &, = 4.7021L % 0.0003 A., ¢o = 3.1328 = 0.0005
A.; for NiF,, a, = 4.6505 % 0.0003 A.; co = 3.0837 * 0.0005 A. Ds. detd.
pycnometrically in benzene are 5.00 + 0.05 g/cc for ZnFo and 4.72 + 0.05

g/cc for NiFo. ZerAm.;875 + 30,