Synthesis and characterization of new fluorosulfinate: NH4SO2F

Journal of Fluorine Chemistry, 4 7 (1990) Received:

May 15, 1989; accepted:

SYNTHESIS

lnstitut

ftir

August

AND CHARACTERIZATION

Klaus Heinrich

15 1- 154

151

11, 1989

OF NEW FLUOROSULFINATE:

NH,S02F*

MOOCK

Anorganische

und

Analytische

Chemie

der

Freien

Universitht

Berlin,

FabeckstraBe 34-36, D-1000 Berlin 33 (F.R.G.)

Detlev SijLZLE lnstitut fur Organische Chemie der Technischen Universitlt Berlin, StraRe des 17. Juni 135, D-1000 Berlin 12 (F.R.G.) and Peter KLABOE Department of Chemistry, University of Oslo, P.O. Box 1033, N-031 5 Oslo 3 ( Norway)

SUMMARY Sulfur dioxide fluorosulfinate.

reacts with dry ammonium The infrared

fluoride

and low temperature

to give ammonium

Raman

spectra

of the new salt

are described.

INTRODUCTION Tetramethylammonium by

Seel and

Riehl [I].

and group 1 cation fluorosulfinates Chemically,

fluorosulfinates

fluorides and are used as mild fluorinating reactions

[2]. They

are

formed

by the

were first reported

behave as activated

metal

agents in halogen-fluorine-exchange action

of

sulfur

dioxide

on

the

corresponding fluoride: MF

+ SO2 + MS0 2 F (M = Na, K, Rb, Cs, MeaN)

(1)

Fluorosulfinates of lithium or the group 2 elements have not been observed. This has been explained

in terms of the greater

stability of fluoride

lattices

containing small cations such as lithium or calcium [l]. A comparison of effective

$ Dedicated to Professor 1. Fuchs, Berlin, on the occasion of his 65th birthday. 0022-l 139/90/$3.50

0 Elsevier Sequoia/Printed

in The Netherlands

152

ion radii [3] shows that the radius of the ammonium

cation is well within

the

range of cations of existing fluorosulfinates: Li +

106 pm

Na + 153pm

NH,+

166 pm

Ca*+

114pm

cs + 202 pm

NMe,+

215 pm

Here the synthesis and spectroscopic identification

of the new salt NHaSOzF is

reported.

RESULTSAND DISCUSSION NH4SO2 F is synthesized by the reaction of sulfur dioxide with dried ammonium equation

fluoride

at elevated

pressure and room temperature

1. The progress of the reaction is monitored

in weight

of the solid product. A typical yield is the absorption

percent of the theoretically Ammonium

according to

by observing the increase of over eighty

calculated amount of sulfur dioxide.

fluorosulfinate

decomposes immediately

in the presence of

water and has to be stored in sealed glass ampoules that were previously flame dried. The sensitivity of NH4S02 F to water precluded a satisfactory characterization by

means

of

temperatures

infrared

spectroscopy.

Raman

around -100°C; at room temperature

spectra

were

recorded

at

the compound decomposed

or sublimed in the laser beam. A list of the infrared and Raman active transitions considered

as fundamentals

is given in Table

1, together

with

a tentative

assignment on the basis of the work of MATHIEU and POULET on NH4+ [4] and the work of PAETZOLD and AURICH on KS02 F [5] and our own spectroscopic data for NH4 F. Although

special care is taken to ensure the absence of water

ammonium

(see experimental

fluoride

section) small amounts

in

of HF2- could

always be detected in the spectra. EXPERIMENTAL IR spectra were recorded on a Perkin-Elmer model 883 grating spectrometer. Samples were analyzed were obtained

as Nujol mulls (between

KSR5 plates). Raman Spectra

with a Dilor model RT 30 spectrometer

(triple monochromator).

An argon ion laser (Spectra Physics model 2000) was employed using the 514.5 nm line and an interference

for excitation

filter to remove unwanted

lines from the laser emission. The sample was illuminated

plasma

in the 90 ’ and 180 ’

geometries in a capillary tube of 5 mm inner diameter cooled by a flow of cold nitrogen gas [6].

3089 1403

1399 (vs)

1114(s)

3087 (m,br)

1403 (VW)

1098

abbreviations

Argon 110 cm-‘.

have been used: s, strong;

c The half band width of this Raman band iss.

b The following

a Raman spectrum recorded

m, medium;

w, weak;

ion laser, excitation

365 (w,br)

v, very; br, broad.

line 488 nm.

1182 (vs)

vz (A’)

sym. SO2F bend

sym. SO2 stretch

v6 (A”)

asym. SO2F bend

asym. SO2 stretch

sym. SO2F bend

v3 (A’ 1 sym. SF stretch vg (A”)

370 (w,br)

1183 (w)

496 (vs)

vr (A’)

v4 (F2) bend

v4 (A’)

1167 (s)

496 (s)

595 (s)

1105 (5)

bend

stretch v3 (F2) stretch

v2 (E)

vr (Al)

Td (NH4+) and G (SO2F-j

248 (vs)

483 (vs)

450 (vs,br)‘

590 (w)

1104 (s)

IR 151

in cm-‘)

in point groups

Frequencies

Assignment

to NH4+ and KSOiF (Observed

Raman”

KSOzF

in comparison

1150(w)

580 (w)

600 (VW)

1397

3134

IR

at room temperature.

2006

2009 (VW)

(s)

2845

2870 (m)b

Raman

Raman (-100”c)

IR

NH4+ (41

spectrum of NH4S02F and its assignment

NH4S02 F

The vibrational

TABLE 1

154

KS02 F was prepared according to literature methods [l]. NHIF (MERCK) was purified

and dried

by three

vacuum sublimations

at a bath temperature

of

+ 70°C. SO2 (LINDE) was dried by storage and distillation over CaH2. Preoaration of Ammonium

Fluorosulfinate

(NH4502F)

In the dry box a 350 ccm stainless steel autoclave containing was charged with dried ammonium line sulfur dioxide

fluoride (8.8g,O.24

(309, 0.47 mol) was condensed

autoclave shaken for two days at room temperature. in vacua and the obtained

metal steel balls

mol). On a glass vacuum onto the NH4 F and the

All volatiles were removed

mixture of NH4 F and NH4SO2 F powdered

box. The autoclave was recharged with the powdered added again. This procedure was repeated

in the dry

mixture and sulfur dioxide

twice and 20.59 (85% yield) white

product (m.p. 12O”C, sealed capillary) obtained. Analysis: Found: H 4.7; F 24.1; N 15.0 %. HaFNOzS requires H 4.0; F 18.7; N 13.9%. A sample containing approximately

18 mol% NHa+FHF-requires

H 4.5; F 24.1; N

15.0 %.

REFERENCES 1 F. Seel and L. Riehl, Z. Anorg. A//g. Chem., -282 (1955) 293. 2 A. Zappel, Chem. Ber., -94 (1961) 873. 3 R. D. Shannon, Acta Ctystallogr., A32 (1976) 751. 4 J. P. Mathieu and H. Poulet, Spect~him.

Acta. ,l6(1960)

696.

5 R. Paetzold and K. Aurich, Z. Anorg. A//g. Chem., 335 (1965) 281. 6 F.A. Miller and B.M. Harney, Appl. Spectrosc., -24(1970)

291.