The synthesis of a germylidenide anion by the C-C bond activation of a bis(germylene) is described. The reaction of the 2,6-bis(imino)phenylbromide 1 with nBuLi, followed by reacting with GeCl2.dioxane afforded the chlorogermylene [LGeCl] (2, L = 2,6-(HCNtBu) 2 C 6 H 3 ). It was then reacted with 1 equivalent of lithium in tetrahydrofuran (THF), which proceeded through the reduction of the imine skeleton, along with the C-C bond formation, to afford the bis(germylene) [2-(HC-NtBu)-6-(HC=NtBu)C6H3Ge:]2 (3). It was further reacted with 2 equivalents of lithium in THF, which proceeded through the reduction of the germanium(II) centres, followed by the homolytic cleavage of the C-C bond, to form the lithium germylidenide [LGeLi] 2 (4). Compounds 2 -4 were characterized by NMR spectroscopy and Xray crystallography. Their bonding natures were also investigated by theoretical studies. ASSOCIATED CONTENT Supporting InformationCIF files giving X-ray data for 2−4, a table giving selected crystallographic data of 2−4 and molecular orbitals of 2 -4. These materials are available free of charge via the Internet at http://pubs.acs.org.

The reaction of the 2,6-bis­(imino)­phenylchlorogermylene [LGeCl] (1, L = C6H3-2,6-(HC​NtBu)2) with silver­(I) trifluoromethanesulfonate (AgOTf) in a molar ratio of 2:3 in toluene afforded a mixture of the bis­(germylene)­silver­(I) complex [{L­(TfO)­Ge}2­Ag­(OTf)] (2) and AgCl. Compound 2 was then reacted with 2 equiv of 1,3-dimethyl-4,5-dimethylimidazol-2-ylidene (IMe, :C­{N­(Me)­C­(Me)}2) in toluene to afford 3, which comprises the bis­(germyliumylidene)­silver­(I) complex dication [{L­(IMe)­Ge}2­Ag­(OTf)]2+. Compounds 2 and 3 were characterized by NMR spectroscopy and X-ray crystallography. [{L­(IMe)­Ge}2­Ag­(OTf)]2+ in compound 3 was further elucidated by DFT studies.

The reaction of the N-heterocyclic-carbene-stabilized disilicon(0) complex [IPr→Si═Si←IPr] (1; IPr = :C{N(Ar)CH}2 and Ar = 2,6-iPr2C6H3) with ArN3 afforded the N-heterocyclic-carbene-stabilized siladiimide [ArNSi(IPr)NAr] (2). X-ray crystallography and theoretical studies show that the N-Si-N skeleton in compound 2 possesses considerable double-bond character and the Si atom is stabilized by the N-heterocyclic carbene.

I would also like to extend my heartfelt appreciation to Dr. Xi Hong-Wei and Professor Yim Wai-Leung for their expertise in conducting the theoretical calculations in this thesis. I am grateful to Dr. Li Yongxin for his expertise and patience in the collection and analysis of X-ray crystallographic data throughout my PhD studies. I would also like to thank all administrative and technical support staffs in NTU Division of Chemistry and Biological Chemistry, for their help in one way or another. Special thanks to Ms.