Cobalt(II) tri-tert-butoxysialanethiolates.Synthesis, properties, crystal and molecular structures of [Co{SSi(OtBu)3}2(L)] and[Co{SSi(OtBu)3}2(L)2] type complexes with monodentate nitrogen ligands.

Agnieszka Pladzyk; Barbara Becker; Wiesław Wojnowski; Antoni Konitz

doi:https://doi.org/10.1016/s0277-5387(01)00855-5

Cobalt(II) tri-tert-butoxysialanethiolates.Synthesis, properties, crystal and molecular structures of [Co{SSi(OtBu)3}2(L)] and[Co{SSi(OtBu)3}2(L)2] type complexes with monodentate nitrogen ligands.

Abstrakt

The title heteroleptic neutral cobalt(II) tri-tert-butoxysilanethiolate complexes with monodentate nitrogen bases (L) as additional ligands have been prepared by the reactions of [Co{μ-SSi(O^tBu)₃}{SSi(O^tBu)₃}(NH₃)]₂ (1) with respective bases. For pyridine both types have been prepared — with two (2) or one (3) nitrogen ligand bonded to cobalt(II). [Co{SSi(O^tBu)₃}₂(L)] complexes have been obtained also with 2-picoline (5), 2,4-lutidine (6), 3,5-lutidine (7), and [Co{SSi(O^tBu)₃}₂(L)₂] also with N-methylimidazole (8) and morpholine (9). Molecular and crystal structures of the six compounds have been determined by single-crystal X-ray structural analysis. In 3, 5 and 7 three-coordinated cobalt(II) seems to interact very weakly with two oxygen atoms from two Si(O^tBu)₃ moieties approaching highly distorted trigonal bipyramidal geometry. Compounds 2, 8 and 9 have distorted tetrahedral structures. Both types of complexes gave characteristic electronic spectra, similar within each type.

Title compounds were prepared by the reactions of [Co{SSi(O^tBu)₃}₂(NH₃)]₂ with heterocyclic nitrogen bases. For six of them X-ray crystal structures were determined. Those with one nitrogen ligand and three-coordinated cobalt(II) seem to be stabilized in a solid state by very weak interactions between metal and oxygen atoms from silanethiolate ligands.