The SF5 anion

Interactions between SF4 and Fluoride: A Crystallographic Study of Solvolysis Products of SF4·Nitrogen-Base Adducts by HF

“…Excess SF 4 and SOF 2 were pumped off at −90°C, yielding a colorless crystalline solid. The use of 0.006 g (0.3 mmol) of water and 0.038 g (0.41 mmol) of 4-methylpyridine in excess SF 4 (0.311 g, 2.88 mmol), corresponding to an HF-to-4-methylpyridine ratio of 1.5:1 gave, after removal of volatiles at −70°C, a white powder that was identified by Raman spectroscopy as [HNC 5 ]F − ·SF 4 . Method 1.…”

“…1,2 Low-temperature Raman spectroscopic and X-ray crystallographic studies showed that SF 4 is Lewis acidic toward organic bases, forming 1:1 adducts with the nitrogen bases, trimethylamine, 3 pyridine, 4-methylpyridine, 2,6-dimethylpyridine, and 4-(dimethylamino)pyridine. 4 These adducts are stable below −40°C under dynamic vacuum and exhibit N---S IV dative bonds ranging from 2.141(2) to 2.514(2) Å. Sulfur tetrafluoride can also act as a Lewis acid toward strong fluoride ion donors, forming the SF 5 ] salt, which was first reported in 1963. 5 The Rb + , Cs + , and [(CH 3 ) 2 N] 2 S + salts of the SF 5 − anion have since been prepared and characterized by vibrational spectroscopy.…”

“…4 These adducts are stable below −40°C under dynamic vacuum and exhibit N---S IV dative bonds ranging from 2.141(2) to 2.514(2) Å. Sulfur tetrafluoride can also act as a Lewis acid toward strong fluoride ion donors, forming the SF 5 ] salt, which was first reported in 1963. 5 The Rb + , Cs + , and [(CH 3 ) 2 N] 2 S + salts of the SF 5 − anion have since been prepared and characterized by vibrational spectroscopy. 6 ■ RESULTS AND DISCUSSION Synthesis and Properties.…”

“…The reaction of a 2:1 mixture of 4-methylpyridine and water in excess SF 4 , corresponding to a 1:1 ratio of SF 4 ·4-NC 5 …”

“…The byproduct, thionyl fluoride, did not interfere with the reaction chemistry and could be removed under dynamic vacuum at low temperature. Attempts to obtain crystals of [HNC 5 …”