Phenylmercury(II) derivatives of tetraorganodichalcogenoimidodiphosphorus acids. Crystal and molecular structure of [PhHg{(OPR2)(SPPh2)N}]2 (R=Me, Ph)

The reactions between PhHgCl or PhHgAc and M[(XPR2)(YPR′2)N] (M=Na, K; X, Y=O, S; R, R′=Me, Ph, OEt), in 1:1 molar ratio, have been investigated. PhHg[(XPR2)(YPR′2)N] derivatives were isolated as microcrystalline powders and were characterised using IR and NMR (1H, 13C and 31P) spectroscopy and mass spectrometry. The molecular structure of PhHg[(OPR2)(SPPh2)N] [R=Me (1), Ph (2)] was investigated by X-ray diffraction. In the monomeric unit, PhHg[(OPR2)(SPPh2)N], the mercury atom forms the primary bonds with the carbon of the phenyl group and the sulfur atom of the phosphorus ligand [Hg(1)–S(1) 2.405(1) Å for 1, 2.398(2) Å for 2]. These primary bonds are significantly deviated from the expected linear arrangement [C(1)–Hg(1)–S(1) 166.4(2)° for 1, 165.0(2)° for 2]. Both compounds exhibit dimeric associations in the crystal through S,O-bridging organophosphorus ligands [Hg(1)–O(1) 2.556(4) Å for 1, 2.588(4) Å for 2], thus resulting in a distorted T-shaped arrangement of the CHgSO coordination core.. The formation of a 12-membered Hg2O2S2P4N2 ring with different conformation in 1 and 2, respectively, results in different additional chalcogen atoms being in the proximity of the metal atom. Weak transannular Hg⋯O [2.753(4) Å] are also established in 1, leading to a tricyclic ladder structure with a planar central Hg2O2 ring.