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(N^tBu)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.