A Straightforward Synthesis of Neutral Hexacoordinated Silicon(IV) Complexes with SiN6 Skeleton

Abstract Three neutral hexacoordinate silicon(IV) complexes with SiN6 skeleton were obtained via one-pot synthesis by using tetra(thiocyanato-N)silane, Si(NCS)4 with an equimolar amount of 2,2′-bipyridyl (bipy), 4,4′-dimethyl-2,2′-dipyridyl (dmp) and 1,10-phenanthroline (phen) respectively. The complexes obtained; (bipy)Si(NCS)4 (1), (dmp)Si(NCS)4 (2), and (phen)Si(NCS)4 (3) belong to a family of neutral hexacoordinate silicon(IV) with SiN6 coordinating framework, which has been less studied both by single-crystal X-ray diffraction and 29Si NMR spectroscopies. All the complexes were characterized by single-crystal X-ray diffraction, solution 1H, 13C{H}, 29Si, solid-state 29Si CP/MAS NMR spectroscopies, and elemental analysis was used to confirm the structures. Comparison of the 29Si chemical shieldings of the complexes 1-3 in the solution and solid-state indicated that all complexes maintain the hexacoordination at silicon atom in DMSO-D6 solution. This works demonstrated the synthetic potential of Si(NCS)4 for the synthesis of new neutral hexacoordinate silicon complexes with SiN6 skeleton via one-pot synthesis.