The chemistry of heteroallyl derivatives of technetium. Reactivity of [TcNCl2(PPh3)2] and [Tc(CO)3Cl(PPh3)] with thiazetidine ligands, crystal structures of [Tc(CO)2(PPh3)2{PhNC(OEt)S}] and [TcN(Cl)(PPh3)-{PhNC(OEt)S}

Abstract

The complex [Tc(CO)3Cl(PPh3)] reacts with the sodium salt of PhNC(OEt)SH to give the thiazetidine complex [Tc(CO)2(PPh3)2{PhNC(OEt)S}](1). The complex [TcNCl2(PPh3)2] reacts with an excess of the neutral ligand to give [TcN(Cl)(PPh3){PhNC(OEt)S}](2). When the reaction is carried out in presence of the ligand salt the disubstituted complex [TcN{PhNC(OEt)S}2](3) is obtained. The crystal structures of (1) and (2) were determined by X-ray crystallography and refined to conventional R factors of 0.0295 and 0.0649 respectively. Compound (1) is monoclinic, space group P21, with a= 12.825(5), b= 16.713(5), c= 9.480(5)A, β= 94.29(3)°, and Z= 2. The technetium environment is distorted octahedral. Selected bond distances are: Tc–P(1) 2.423(1)A, Tc–P(2) 2.456(1), Tc–S 2.529(1), Tc–N 2.228(5), and Tc–C 1.89(1)A(mean). Compound (2) is triclinic, space group P, with a= 9.428(5), b= 10.237(5), c= 15.603(5)A, α= 89.29(3), β= 102.74(3), γ= 115.61 (3)°, and Z= 2. The environment of Tc is distorted square pyramidal with the nidrido N atom as apex. Selected bond distances are: Tc–N (nitrido) 1.615(7), Tc–N (ligand) 2.135(7), Tc–S 2.375(3), Tc–Cl 2.366(2), and Tc–P 2.429(2)A.