Comparisons of zinc with cadmium in N_2S_2 coordination and as S-bonded adducts to tungsten carbonyls

摘要

The synthesis and characterization of bis-mercaptoethanediazaheptane cadmium(ii) is reported and compared to the analogous zinc complex. Of significance is the dimeric form of the [Zn(N_2S_2)] _2 complex achieves penta-coordination about zinc through a bridging thiolate whereas cadmium engages two thiolate as S-bridges resulting in hexa-coordination about cadmium within a coordination polymer whose X-ray crystal structure is reported here. In the presence of W(CO)_5, this polymer breaks up, generating dimeric [Cd(N_2S_2)] _2 with two W(CO)_5 units appended to the terminal thiolates, a feat that is not observed for the zinc dimer analogue. The greater thiophilicity of cadmium over zinc is noted in several features of these complexes. This journal is