Preparation and crystal structure of the tetramethylammonium thiocyanate sulfur dioxide adduct, (CH3)(4)N+SCN-center dot SO2

Tetramethylammonium thiocyanate reacts with sulfur dioxide under formation of tetramethylammonium thiocyanate sulfur dioxide adduct. The resulting sal t is characterised by NMR and vibrational spectroscopy and its crystal stru cture. (CH3)(4)N+SCN- . SO2 crystallizes in the monoclinic space group P2(1 )/c with a = 578.4(1) pm, b = 1634.3(1) pm, c = 1054.6(1) pm, beta = 105.17 (1)degrees, and four formula units in the unit cell. The crystal structure possesses a strong S-S interaction between the NCS- anion and the SO2 molec ule. The NCS-SO2 distance of 301.02(9) pm is longer than a covalent single bond, thus the compound is rather described as an adduct. The structure is compared with ab initio calculated data.