The structures of [Ph2XSNSPh2NH]+ cations (XNH, O)

Diphenyl(diphenylsulfodiimidoyl)(nitrido)sulfur(VI) (2) and diphenyl(diphenylsulfoximidoyl)(nitrido)sulfur(VI) (3) (Ph2XSNSNPh2N, X=NH, O) were prepared by the reaction of diphenyl(fluoro)(nitrido)sulfur(VI) (Ph2FSN) with sodium salts of diphenyl-sulfodiimide (Ph2S(NH)2) and -sulfoximide (Ph2OSNH). The nitrido-sulfur complexes 2 and 3 are considerably basic (pKa=7.86 and 7.60, respectively). Treatment of 2 and 3 with perchloric acid afforded quantitatively the corresponding μ-aza-bis[diphenyl(imido)sulfur(V)] perchlorate (4) and μ-aza-[diphenyl(imido)]-[diphenyl(oxo)]disulfur(V) perchlorate (5) ([Ph2XSNSPh2NH]+[ClO4]−, X=NH, O). The crystal structures of 4 and 5 were determined by X-ray crystallographic analysis. The former has essentially C2 symmetry with an SNS bond angle of 120.3(2)°, bridging SN bond lengths of 1.595(3) and 1.604(3) Å, and terminal SN bond lengths of 1.509(3) and 1.497(3); the latter cation is an unsymmetrically substituted oxygen analog with an SNS bond angle of 123.1(2)°, and bridging SN bond lengths of 1.607(4) and 1.568(4) Å, terminal SN and SO bond lengths of 1.501(3) and 1.438(2) Å. Single-point ab initio calculations were also carried out using the data from the crystal structures of 4 and 5.