Recent advances in η2-disilene and η2-disilyne mononuclear transition metal complexes and related compounds

Recent progress of η 2 -disilene and η 2 -disilylne mononuclear transition metal complexes and related complexes are summarized. Although examples for disilene-transition metal complexes are still limited for group 4, 6, 8, 10 and 11 metals, η 2 -disilene transition metals complexes have been synthesized by various synthetic methods and structural characteristics are well discussed by using X-ray diffraction analysis, 29 Si NMR resonances and Dewar–Chatt–Duncanson model. Reactions of these complexes have been also investigated. Very recently, η 2 -disilyne-group 10 metal complexes have been synthesized. In addition, transition metal complexes with doubly-bonded silicon compounds such as silenes (R 2 Si CR′ 2 ), silanimines (R 2 Si NR′), silanones (R 2 Si O) and related doubly-bonded germanium and tin compounds as η 2 -ligands are briefly summarized.