Nitrogen fluorides have been recently extensively studied. The triple point of nitrogen trifluoride was found by Pierce and Pace*5 5 1) to be 66.37°K and the same authors measured the heat capacity and vapor pressure from 12 to 144°K. The heat of transition at 56.62°K was found to be 361.8 cal per mole. The heat of fusion at the triple point temperature was found to be 95.1 cal per mole. The heat of vaporization at the normal boiling point 144.15°K was found to be 2769 cal per mole. The vapor pressure measurements are represented by the equation,
logioPmm = 4.64615 - 673.5828/r + 1.869858 logio T - 0.0078335571 The entropy of the gas calculated from calorimetric data and the third law at 144.15°K is 54.50 cal per deg per mole and calculated from spectro
scopic data on a pyramidal model, 54.61. Jarry and Miller*3 6 6) also deter
mined the vapor pressure; and it was found to follow the equation logio Pmm = 6.77966 - 501.913/T - 15.37 from 89 to 144°K and
50 J . H . SIMONS
logio Pmm = 4.27264 - 613.33/T from 149 to 324°K. The density of the liquid from 78 to 170°K was d = 2.103 - 3.294 x 10"3 T - 4.675
x 1 0-6 T2g m p e r m l . The normal boiling point was 144.10°K. The critical temperature is 233.90 ± 0.10°K and the critical pressure 44.72 ± 0.17 atm.
The structure of NF3 was studied by means of microwave spectra by Sheridan and Gordy<3 7 5). The N — F distance was found to be 1.371 A and the < F N F = 102°9/. Further microwave studies in the 2 to 3 mm region were made by Johnson, Trambarulo, and Gordy<373>. The infrared and Raman spectra of NF3 was reported by Pace and Pierce<5 2 7 ), the infrared spectra by both Wilson and Polo<791> and Schatz and Levin<6 1 6).
Schatz*6 1 5) discusses its potential functions. Schoemaker and Lu<6 3 3) by electron diffraction found the N—F distance to be 1.37 ± 0.02 A and a bond angle < F N F = 102.5° ± 1.5°. The F • • • F distance is 2.14 A.
By means of Stark effect studies, Ghosh, Trambarulo, and Gordy<264>
determined the electric dipole moment of NF3 to be 0.234 ± 0.004 Debye units. This was discussed theoretically by both Mashima<458> and Kisliuk<4 0 4). The heat of formation at 25° was found by Armstrong, Marantz, and Coyle<19) to be —29.7 ± 1.8 kcal per mole and the dissoci
ation bond energies D(NF2—F) = 74.0, D(NF—F) = 62.6 and D(N—F) = 62.6 kcal per mole.
Dinitrogen difluoride, N2F2 was prepared by Colburn et alS136) by passing an electric current through molten NH4F • H F at 120-130°. They found both cis and transforms and determined infrared and NMR spectra for each form. The vapor pressure of the trans isomer follows the equa
tion, logio Pmm = 7.470 - 742.3/T with a boiling point of -111.4°, a critical temperature of —13°, a melting point of —172°, a heat of vaporization of 3400 cal per mole, and a critical pressure of 55 atm. For the isomer, logio Pmm = 7.675 — 803.0/T, the boiling point is —105.7°, the critical temperature —1°, the melting point, below—195°, the heat of vaporization 3670 cal per mole, and the critical pressure 70 atm. Both isomers react with glass. The cis isomer reacts more rapidly with mercury than does the trans. When heated the trans isomer was converted into the cis isomer. They, however, probably exist in equilibrium. The infrared spectra and structures of the isomers are reported by Sanborn<6 1 2 a).
Loughran and Mader<44°) reported the bond dissociation energy of N—N bond in dinitrogen tetrafluoride undergoing electron bombardment as 1.3 ev ± 0.3. In a mass spectrometric study Herron and Dibeler(3 2 5 a>
found the ionization potential of N2F4 to be 12.04 ± 0.10 ev, that of SiF4 15.04 ± 0.4 ev, the appearance potential of N F2+ to be 12.7 ev, and the dissociation energy of the N—N bond 53 kcal per mole. Colburn and Johnson<1 3 5 a> however, find for the reaction N2F4 ^ 2NF2, A H = 19.2 kcal
per mole and AS = 38.6 e.u. Dinitrogen difluoride and dinitrogen tetra
fluoride, N2F4, were made by Frazer( 2 4 2) by passing NF3 and mercury through an electric field. Morrow, Perry, and Cohen<4 9 2) obtained this compound by the reaction of elementary fluorine diluted with nitrogen with excess ammonia. Morrow et #/.<4 9 2 a) found N2F2 and NHF2 to be additional products of this reaction in a packed copper reactor. If an excess of F2 was used, NF3 and NH4F were obtained. Colburn and Kennedy*1 3 7) made dinitrogen tetrafluoride by the reaction of NF3 on various metals at 375°. The vapor pressure is logio Pmm = 6.33 — 6 9 2 / 71 with a boiling point of — 73° and heat of vaporization of 3170 cal per mole.
The critical temperature is — 36° at a critical pressure of 77 atm. Dresdner, Tlumac, and Young<1 8 3 a) made N2F4 in 6 0 % yield by the reaction of
N F3 and Hg at 3 2 0 to 330°.
Dinitrogen tetrafluoride is a reactive substance. It has been found by Frazer<242a> to react with CH3I and C2H5I with ultraviolet excitation to form CH3NF2 and C2H5N F2, C H3N F2 has a melting point, - 1 1 4 . 8 ° ,
a boiling point, —1 6 ° , a density at —20° of 1.099, a AH of vaporization of 5 . 4 8 kcal per mole, and a vapor pressure in the range —69 to — 1 9 . 3 ° ,
logio Pmm = 5.6731 - 7 5 5 . 1 5 T -1 - 5 6 , 6 3 1 T -2. C2H5N F2 has a melting point of - 150.3°, a boiling point of 14.9°, a density at 0° of 1.0167, a AH of vaporization of 6.14 kcal per mole, and a vapor pressure in the range
- 3 3 . 0 to 14.4°, logio Pmm = 5.7005 - 8 5 6 . 3 0 P "1 - 7 0 , 3 4 5 71"2. Lawton et tf/.<428b) obtained N F2H and also F2N C O N H2 by the reaction of F2 diluted 1 to 5 or 10 in N2 with urea. N, N difluorourea was found to melt at 4 1 . 0 ° . Difluoroamine NHF2 was reported by Lawton and Weber<429>
from the reaction of fluorine and urea at 0°. A corrosive fluorine contain
ing liquid was obtained which on distillation yields HNF2. This substance loses hydrogen on contact with various solids to form dinitrogen tetra
fluoride. If it is chilled to — 196° the solid detonates spontaneously. If chilled to —142°, it can be handled in small amounts. Its melting point is - 1 1 6 ± 3°, boiling point - 2 3 . 6 ° , and density, d = 1.424 - 0 . 0 0 2 0 2 *
gm per cm3. Small amounts were obtained by Kennedy and Colburn<3 9 1) in the reaction to produce dinitrogen tetrafluoride between nitrogen trifluoride and arsenic at 2 5 0 - 3 0 0 ° . They reported its vapor pressure to be represented by the equation, logio Pmm = 8 . 0 7 2 — 1 2 9 8 / P , its boiling point —23°, its heat of vaporization 5 9 4 0 cal per mole, its melting point
— 131°, and its critical temperature 130° at 93 atm. This compound was obtained from dinitrogen tetrafluoride by reaction with thiophenol in an evacuated bulb in 7 5 % yield by Freeman, Kennedy, and Colburn*2 4 3).
Cyanuric fluoride, which boils at 7 2 . 4 5 ° at 7 6 0 mm was made by Seel and Ballreich<647) by the reaction of cyranuric chloride and KSO2F. It has the formula C3F3N3. Its vapor pressure is given by the equation,
52 J. H. SIMONS
l o g P = 8.442 - 1940/T ± 0.0085 with a heat of vaporization of 8.85 kcal per mole and a freezing point of —38°. Chlorodifluoronitrogen, CIF2N was prepared by Petry*5 4 9) by heating to room temperature the white solid formed by condensing HNF2 and BCI3 together at 130°. It is a colorless air stable gas. Its vapor pressure fits the equation,
logio Pmm = 7.478 - 950/T.
The boiling point is — 67°, the heat of vaporization is 4350 cal per mole, and the Trouton's constant is 21.0.
Nitrosyl fluoride NOF and nitryl fluoride NO2F were prepared free from silicon containing impurities by the reaction of fluorine with NO and N 02 by Faloon and Kenna<2 1 7). Nitrosyl fluoride boiled at 213-14°K and nitryl fluoride at 200-l°K. Johnson and Bertin*3 7 4) found for the reaction, NO + | F2 = NOF, AH = - 74.8 kcal per mole. This gives
— 15.8 kcal per mole for the AH of formation and 55.4 kcal per mole for the reaction, ONF ->NO + F.
The molecular structure of NOF was given by Magnuson*4 4 4) to have an N—F distance of 1.52 A and N—O distance 1.13 A, and < ONF = 110°.
The infrared spectrum of the compound was studied by Woltz, Jones, and Nielsen*7 9 7) and by Magnuson*4 4 7).
Nitryl fluoride has been prepared by Schmeisser and Elischer*6 1 9) by the reaction of silver fluoride on NO2CI at 240° or by passing H F + BF3 into a solution of N2O5 in nitro methane to form N 02 * BF4 crystals.
These on heating with NaF at 240° gave nitryl fluoride. Aynsley, Hether-ington, and Robinson*27) made the compound in glass by the reaction of fluorine with sodium nitrite and found it to boil at — 73 to — 72° and freeze at about —160°. They found the compound to react with non-metals to give nitronium salts such as
( N 02) A u F4 N 02S e F5 N 02P F6 ( N 02)2S i F6
( N 02) B F4 N 02T e F5 N 02A s F6 ( N 02)2G e F6
( N 02) B r F4 N 02S b F6 ( N 02)2S n F6
Hetherington and Robinson determined some of the physical properties of nitryl fluoride. They found the melting point —166°, the boiling point —72.5°, the density at —101° = 1.571 gm/cm, the surface tension at -104.5 = 27.6 dynes per cm, the viscosity at -101° = 0.00572 and at -72.5° = 0.00460 P, and the critical temperature of 76.3°. Ogg and Ray*5 1 5) prepared nitryl fluoride by the reaction between N2O5 and NaF at about - 1 1 0 ° : N F + N20 5 = N a N 0 3 + F N 0 2. Dodd, Rolfe, and Woodward*1 7 4) determined its infrared and Raman spectra. Cook et a/.*1 4 0 a) determined the infrared spectra of NO2F complexes with BF3, PF5, and SbFs.
The infrared spectrum of N2H6F2, hydrazine dehydrofluoride, is reported by Snyder and Decius*7 0 3).
Potassium monofluoronitrile, 2K2NO2F, was prepared by Ray and Ghosh*5 6 9) by treating K F in concentrated aqueous solution with N2O3.
Many nitrosyl or perhaps more correctly nitrosonium compounds of various fluorides have been prepared. For example, Woolf*7 9 9) lists as old compounds NOBrF4, NOAsF6, NOSbF6, NOBF4, NOSnF6, and new ones NOAuF4, NOPF6, (NO)2GeF6, (NO)2SnF6, and NOSO3F.
Chretien and Bouy*1 2 3) prepared N O B F4 by a reaction between FNO and BrF3 or 3NO + 4BrF3 -> 3NOBrF4 + iBr2. They used the compound to prepare the solid (NO^SiFg by reaction with SiF4. Roberts and Cady *5 7 8) prepared NOSO3F by reaction of NO with S2O6F2 and found it to melt at 156-157°, to have a density of 1.98 gm per ml at 25°, and to react readily with water.
Nitrososulfuryl fluoride, NOSO2F, was prepared by Seel and Massat*6 5 4). It was found to melt at 8° under pressure and to react with various elements and chlorides to produce nitrosonium fluorides; for example, with Se or SeCl4, (NO)2SeF6 was prepared, also (NO)2TiF6 and (NO)2TeF6 were prepared. Nitrosyl hexafluorophosphate was prepared by Seel and Gossl*6 5 2) by the reaction NOSbCl6 + M e4N p F41i ^ ^ NOPF6. It is a salt-like compound.
Nitronium compounds of various fluorides have also been prepared.
Woolf and Emeleus*8 0 3) prepared N 02B F4, N 02A u F4, N 02P F6, N 02S b F6, NO2ASF6, and (N02)2SnF6 by means of BrF3. Nitronium fluorosulfanate, NO2SO3F, was prepared by Goddard, Hughs, and Ingold*2 7 3) from dinitrogen pentoxide and fluorosulfonic acid, which melts at 200° with decomposition.
The crystollography of the two phosphonitrilic fluorides was studied by Jagodzinski, Langer, Opperman, and Seel*3 6 3). (NPF2)3 was shown to be rhombic and (NPF2)4 monoclinic. Schmitz-Dumont and Walther*6 2 9) found the melting point of (NPF2)4 to be 32° and (NPF2)3 to be 28°.
The compounds are best prepared by the method given by Seel and Langer*6 5 3) which treat (PNC12)4 or (PNC12)3 with K S 02F at 110° or in P h N 02 at 80-90° for (PNF2)4. Ratz and Grundmann*5 6 3*) used AgF for this reaction. Mao, Dresdner, and Young*4 8 8) prepared both trimer and tetramer by treating P3N5 with either CF3SF5 or NF3 at 700°.
From both Raman and infrared spectra Becher and Seel*5 5 a) deter
mined the vibration spectra of liquid (NPF2)3 and gaseous (NPF2)4. They found (NPF2)3 to be a planar 6-membered PN ring with D^h symmetry and (NPF2)4 to be a nonplanar PN ring with C^h symmetry.
Higher members of the phosphonitrilic fluorides have been made by Chapman e t a l A1 2 1K They have the formulas (PNF2)W, where n = 3 to 11,
5 4 J. H . SIMONS
and are cyclic in nature. Polymers up to (PNF2)i7 were also described.
They were made by treating the phosonitrilic chlorides by a mixture of potassium fluoride and sulfur dioxide. According to Seel and Langer*6 5 3) the trimer has a vapor pressure that fits the equation, l o g Pmm = 11.82
- 2810/JT from 0 ° to the triple point at 2 7 . 8 ° and l o g Pmm = 8 . 0 4
— 1 1 7 0 / 71 from the triple point to 5 0 ° . It boils at 50.9°, has a triple point pressure of 306.3 mm, a heat of sublimation of 12.8 kcal per mole, a heat of vaporization of 7.6 kcal per mole, a heat of fusion of 5.2, and an entropy of vaporization of 23.5 cal per degree. The tetramer has a vapor pressure that fits the equation, l o g Pmm = 1 1 . 7 6 - 3 0 1 3 / T from 0 ° to the triple point at 3 0 . 5 ° and log Pmm = 8 . 2 6 - 1 9 5 2 / T from the triple point to 9 0 ° . It boils at 89.7°, has a triple point pressure of 6 8 . 0 mm, a heat of sublima
tion of 13.8 kcal per mole, a heat of vaporization of 8.9, a heat of fusion of 4.9, and an entropy of vaporization of 24.6 cal per deg.
Glemser and co-workers*2 7 2'6 3 4) have prepared a number of compounds of nitrogen, sulfur, and fluorine. By treating S 4 N 4 with AgF2 in dry
C C I 4 they obtained S 4 F 4 N 4 , which melts at 1 5 3 ° with decomposition and which has a density D 420 = 2 . 3 2 6 . They also obtained SN2F2, which melts at — 108°, boils at 11° with a heat of vaporization of 5.4 kcal per mole and a density at —80° of 1.57 gm per ml, and another product identified as SNF. By boiling a mixture of S 4 N 4 with AgF2 in C C I 4 followed by low temperature distillation SNF was prepared. It also was prepared by the reaction of S 4 N 4 with AgF2 or C 0 F 3 in C C I 4 and by the thermal decompo
sition of S 4 N 4 F 4 in C C I 4 . It has a A i/Va p of 6 0 5 2 cal per mole and a Trouton's constant of 22.1. It is a colorless gas that reacts with glass at room temperature. It condenses at about + 0 . 4 ° to a yellow liquid that freezes at about - 8 9 ° . It reacts with B F3 to form SNF • BF3(?) and with CI2 to form S N C 1 . It hydrolyses readily. X-ray diffraction patterns showed an asymmetrical structure with the sulfur atom at one end of the molecule. The bond distance found were S—N = 1.59 ± 0.05 A, N—F = 1.42 ± 0.05 A, and the bond angle SNF = 1 2 0 ± 5°. By treat
ing SNF with S N2F2 at 2 0 ° S N F3 was obtained in 9 0 % yields. This presumably is F2SNF, as it hydrolyses to give NH4+, F~, and S O 3 — .
It boils at —23°, freezes at — 81°, has a density at — 8 0 ° of 1.92 gm per ml, and a heat of vaporization of 5211 cal per mol. By the reaction of SNF with AgF2 was formed N S F 3 among other products. It boils at 2 7 . 1 ° ,
freezes at —72.6°, has a heat of vaporization of 5 5 2 6 cal per mole, and a Trouton's constant of 22.5. It combines with B F 3 to form unstable
N S F 3 • B F 3 . Heating SN2F2 in quartz at 2 5 0 ° and at a pressure of 3 0 0 mm of Hg, N2, SiF4, NSF, and other products are formed. N S F melts at —79°, boils at 4 . 8 ° , has a density of 1.38 gm per ml at —60°,
a heat of vaporization of 5.3 kcal per mole, and a Trouton's constant of
19.1. This compound is an isomer of SNF. If SN2F2 is decomposed at its boiling point, there is formed N2, NSF, SNF2, and a colorless SNF compound, not yet identified which melts at 20° and boils at 60°. S3N2F2 resulted from the combination of SNF2 and SNF in glass at 20° and 600-700 mm pressure. It melts at 85°, decomposes at 95.7°, and sublimes at 40°. It is believed to be FSNSNSF. S3N3F3 was prepared from S3N3CI3 and AgF2 suspensions in CCI4. It has a melting point of 74.2 and boils at 92.5°. The S3N3CI3 was prepared from S4N4 by treating a supension of S4N4 with Cl2 in CC14. At 80 to 100° S4N3CI reacts with H F to form S4N3F • 1.5HF.
Rogowski*5 4 9 a) determined the structure of SNF by electron diffraction and found the S—N distance to be 1.62 ± 0.03 A and the N—F distance, 1.42 ± 0.03 A. SNF angle was found to be 122 ± 3°. The crystal struc
ture of (NSF)4 was examined by Wiegers and V o s( 7 8 3 a) . They found it to be a puckered ring of alternating sulfur and nitrogen atoms. The fluorine atoms are attached to the sulfur atoms. The nitrogen to sulfur bonds are alternately single and double of lengths, 1.65 ± 0.02 and 1.55 ± 0.02 A.
The sulfur-fluorine bond length is 1.64 ± 0.02 A. The angles are SNF, 123°; NSN, 112°; FSN, 91°; and FSN, 106°.
Phosphorus trifluoride was reported prepared by Hoffman*333) by the slow addition of ASF3 to PCI3 at room temperature. It was prepared by Williams*7 8 8) by the addition of PCI3 to anhydrous ZnF2. Muetterties et a/.*4 9 5 a) prepared it at 300 to 400° from PC12 and CaF2. They also prepared PF5 from PCI5 in a similar reaction. Its heat of vaporization is 3489 cal per mole, its Trouton's constant 30.2 cal per deg per mole, its critical temperature —2.05°, its critical pressure 42.69 atm, its vapor pressure, log P mm = 7.310 - 761.4/P, its B.P. = - 101.1°, and its f.p. =
— 151.5°. Its dipole moment was calculated by Sobhanadri*7 0 3 a). POF3 was also prepared by Montel*4 9 0) by the reaction at 300-900° of P20 5 and CaF2. POF3 was also prepared by Wilkins*7 8 6) by refluxing POCI3 for eight hours with NH4F. POCIF2 was produced at the same time.
By refluxing PC13 with N H 4F he obtained PC12F and P F 3. Kolditz*4 0 9) prepared [PC14]+[PF6]- by treating P 2C l i 0 in AsCl3 with AsF3. It is a white solid which sublimes at 135°. Upon heating in vacuum, it gives PCI4F, which melts at - 6 3 ° and boils at 67°. PF3C12, which is readily made by the combination of CI2 with PF3, is reported by Kennedy and Payne*3 9 2) to melt between - 1 2 5 and -130°, boil at 7.1°, have a AH of vaporization = 5.66 kcal per mole, a value of 20.2 for the Trouton's constant, and vapor pressure logio Pmm = 7.264 — 1228/P. It slowly is converted in the vapor to the white solid [ P C l 4]+[ P F 6 ] ~ .
PF3 and B2H6 were found to react under pressure in sealed tubes by Parry and Bissot*529) to give F3PBH3. This compound is a colorless gas
56 J. H . SIMONS
which is spontaneously inflammable in air. Its melting point is
— 116.1 ± 0.2°, boiling point —61.8°, it has a heat of vaporization of 4.760 kcal per mole, and Trouton's constant of 22.5. Its vapor pressure fits the equation, logio Pmm = 7.8061 — 1038.9/T. The compound F3PBD3 was similarly made. It has a melting point of —115.1 + 0.1°, boiling point of — 59.8°, heat of vaporization of 4.630 kcal per mole, a Trouton's constant of 22, and a vapor pressure that follows the equation, logio Pmm = 7.6171 - 1010.8/7\ Boron trifluoride reacted with tri-methylphosphine oxide to form ( C H 3 ) 3 P O B F 3 with a melting point of 149° according to Burg and McKee*9 7).
The infrared spectrum of PF5 was determined by Pensler and Planet*5 4 2) on a sample prepared by the thermal decomposition of NaPFg in a nickel vessel. The infrared spectra of PF3, POF3, and PF5 were reported by Gutowsky and Liehr*2 8 5) and that of PF3 by Wilson and Polo*7 9 1). Daasch and Smith*1 5 8) reported the infrared spectra of P F3, P O F 3, PSC12F, (MeO)2POF, (EtO)2POF, and E t 2N P F 2. The Raman spectra of P F 3, PFC12, PFB2, PFClBr, POF3, POFCl2, POFCl2, POFBr2, POFClBr, POF2Cl, POF2Br, PSF3, PSFC12, PSFBr2, PSFClBr, PSF2C1, and PSF2Br were reported by Delwaulle and Frangois*1 6 5) and the Raman spectrum of PF3 • BD3 by Taylor and Bissot*7 3 0).
The microwave spectra of POF3 and PSF3 were determined by Williams, Sheridan, and Gordy*7 8 9). For P O F3 dF0 = 1.45 ± 0.03 A, rfpF = 1.52 ± 0.02 A, and < F P F = 102.5 ± 2°. For P S F 3 rfPS = 1.89
± 0.03 A, dFF = 1.53 ± 0.02 A, and < F P F = 100.3 ± 2°. Hawkins, Cohen, and Koski*3 0 8) also reported the microwave spectra of POF3 and P S F3. They found for POF3rfp0 = 1.48 A,rfPF = 1.52, < F P F = 106°
and for P S F3, dFS = 1.86 A, dFF = 1.53 A, < FPF = 100°. From micro
wave absorption spectra Senatore*6 5 9) determined the dipole moment of POF3 to be 1.735 Debye units. The microwave spectra of NF3PSF3 and PF3 were determined in the 2-3 mm region by Johnson, Trambarulo, and Gordy*3 7 3). The dipole moment of P F3 from the Stark effect was found to be 1025 ± 0.009 Debye units by Shulman, Daily, and Townes*6 7 6).
Using a similar method Ghosh, Trambarulo, and Gordy*2 6 4) determined the dipole moments of P O F3 to be 1.77 ± 0.02 and P F 3 to be 1.03 ± 0.01 Debye units. The electrical conductivity of PF3 was found by Woolf*8 0 2) to be 0.42 x 10~8 mho at 113°. The molecular and crystal structure of
( P C F 3 ) 5 was studied by Spencer and Lipscomb*7 0 5 a).
[ P B r 4 ] [ P F 6 ] was prepared by Koditz and Feltz*4 1 1). It is reported to sublime at 135°. The crystal structure of T i P F 6 was reported by Bode and Teufer*70) and the infrared spectra of K P F 6 by Lattre*4 2 7).
The preparation of the hexafluorophosphates of sodium, potassium, and ammonium, M P F 6 , by adding either the alkali chloride or fluoride
to liquid H F and then adding PCI5 was described by Woyski*8 0 6).
Muetterties et a/.*4 9 5 a) performed the reaction 3MF + 5PF3 i5^ 3MPF6 + 2P where M = K or Cs. Sodium monofluorophosphate, Na2P03F, was prepared by Audrieth and Hill*24) by the reaction Na3P30g + 3NaF
-> 3Na2P03F. The silver salt was then prepared by reacting silver nitrate with the sodium salt. The crystal structure of /? K2PO3F was reported by Robinson*5 8 2) a nd the infrared spectrum of N H4P 02F2, ( N H4)2P 03F • H20 , L i2P 03F • 3H20, Na2P03F, K2P 03F , CaP03F • * H20 , SrP03F • * H20 , BaP03F, PbP03F, and A g2P 03F by Corbridge and Lowe*1 4 2).
Larsen et a/. (425) showed that POFCl2, POF2Cl, and P O F3 formed addition compounds with the tetrachlorides of zirconium and hafnium.
These all tended to decompose prior to or at the melting point. The compounds and approximate melting points are: 2POFCI2 • ZrCl4, 74-8°; 2P0FC12 • HfCl4, 80-3°; POFCl2 • ZrCl4, 161-3°; POFCl2 • HfCl4, 165-7°; POF2CI • ZrCl4, 106-9°; POF2Cl • HfCl4, 110-3°; P O F3 • ZrCl4, 85°; and POF3HfCl4, 85°.
Arsenic trifluoride is recommended prepared by the distillation of a mixture of AS2O5, CaF2, and H2S04 by Hoffman*334). Engelbrecht, Aignesberger, and Hayek*2 0 5) made it by the action of HS03F on As203. They found it will combine with S 03 to form 2AsF3 • 3H2O, which boils at
Arsenic trifluoride is recommended prepared by the distillation of a mixture of AS2O5, CaF2, and H2S04 by Hoffman*334). Engelbrecht, Aignesberger, and Hayek*2 0 5) made it by the action of HS03F on As203. They found it will combine with S 03 to form 2AsF3 • 3H2O, which boils at