Carbazole Substituted Amidinato Silylene: Synthesis, Bonding, and Coordination Behavior with Coinage Metals

In
this work, the synthesis and characterization of a new carbazole
substituted amidinatosilylene (1) and its coinage metal
complexes 3–8 are being reported.
Before the complexation reactions, we prepared [PhC­(NtBu)2Si­(Cbz)→Co­(CO)­Cp] complex (2) to estimate
the σ-donating strength of the newly synthesized silylene 1. Further, several commonly available coinage metal salts
were utilized for the complexation reactions with 1,
which afforded complexes 3–8. The
solid-state structures of 1–8 have
been validated by single-crystal X-ray diffraction studies, NMR spectroscopy,
and mass spectroscopy. DFT studies were also performed to understand
the bonding scenario of 1 and 3–7. Of note, 1 consists of a HOMO on its carbazolide
moiety, and the HOMO-1 features the silylene character. We also compared
the HOMO-LUMO gap of 1 with other amidinato silylenes
having different N-substitutions.