Research He works in organometallic chemistry, especially in silicon and heavier group-14 element chemistry. The subjects of most interest in recent years have been synthesis and properties of: Silicon unsaturated compounds An isolable dialkylsilylene, 2,2,5,5-tetrakis(trimethylsilyl)-silacyclopentan-1,1-diyl. New stable Si=Si compounds involving small cyclic disilenes, spiropentasiladiene, various tetrasilyldisilenes, trisilaallene and related heavy allenes, and anthryl- and related aryldisilenes. New stable Si=X compounds involving silatriafulvene, silaketeneimines, and silanechalcogenones. Transition metal complexes with disilene and silylene ligands. Long-bond 1,3-disilabicyclo[1.1.0]butane. Silicon-based molecular machines. Oligosilanes and polysilanes. σ(Si-Si) -π Conjugation systems.