Synthesis and Reactivity of N‐Heterocyclic Silylene Stabilized Disilicon(0) Complexes

Synthesis and reactivity of disilicon(0) complexes are of fundamental and application importance. Herein, we report the development of an N‐heterocyclic imino‐substituted silylene (1), which has strong σ‐donating ability and is significantly sterically hindered. The one‐pot reaction of this silylene with [IPr→SiCl2] (IPr=1,3‐bis(2,6‐diisopropylphenyl)‐imidazol‐2‐ylidene) and KC8 (2 equiv) in THF at −30 °C leads to a silylene‐ligated disilicon(0) complex (2), isolated as red crystals in 60 % yield. Characterization data and DFT calculations show that the trans‐bent Si4 skeleton in 2 features a Si0=Si0 double bond with significant π–π bonding and one lone pair of electrons on each of these two Si0 atoms. Complex 2 reacts readily with phenylacetylene, producing a structurally intriguing silatricyclic complex 6,8‐diaza‐1,2,5‐trisilatricyclo‐[3.2.1.02,7]‐oct‐3‐ene (3), and revealing new aspects of low‐valent silicon chemistry. An N‐heterocyclic silylene ligated disilicon(0) complex was synthesized and characterized, which revealed a Si0=Si0 double bond with significant π–π bonding. Its reaction with phenylacetylene gave the structurally interesting silatricyclic complex 6,8‐diaza‐1,2,5‐trisilatricyclo[3.2.1.02,7]‐oct‐3‐ene and reveals new aspects of low‐valent silicon chemistry.