Synthesis And Reactivity Of Low-Valent Main Group Element Compounds Stabilized By O-Phenylenediamine Ligand

Metal-metal-bonded compounds containing low-valent metal centers have attracted much attention because of their novel structure and reactivity,while the proper choice of ligands with suitable electronic and steric properties is the key to the synthesis of such species Herein,we demonstrate that the ortho-phenylenediamine（H₂L）ligand upon deprotonation to the dianion（L2-）can effectively stabilize a series of E-E bonds,including groups 2（Mg）and 12-15 elements Zn,Ga,Ge,and PThis paper is divided into three chapters:The first chapter is literature review,which briefly introduces the development history of metal-metal bond compounds,typical transition and main group metal-metal bond compounds and their reactivityThe second chapter describes in detail the synthesis and characterization of three stable metal-metal bond compounds[K（THF）3]₂[LZnⅠ-ZnⅠL]（1）,[K（THF）₆]₂[LGeⅠ-GeⅠL]（3）,[LPⅡ-PⅡL]（6）and two heavy carbene compounds[LGeⅡ:]（2）and[LSnⅡ:]（4）,which stabilized by o-phenylenediamine ligand.In addition,the above compounds were characterized by X-ray single crystal diffraction,NMR,EPR,elemental analysis,UV-vis spectroscopy and their electronic configurations were calculated and studied by density functional theory computations,In combination with the previous work of Mg-Mg,Ga-Ga compounds,we found that in the presence of the alkali metal ions（compounds 1 and 3）,the E-E bond length is at the longer end of those for known analogues,while without the K+ions（compound 2）the E-E distance is relatively short.It is worth noting that the Ge-Ge bond length of compound 3 represents the longest analogues reported to date and compound 6 is dimeric only in solid state,and the P-P bond readily breaks homolytically to form a radical species 6A in solution at room temperatureThe third chapter reports the reactivity of compound[K（THF）3]₂[LMI-MIL]（M＝Mg,Zn）to azide molecules（Ph₃CN₃,Me3SiN₃）.During the reaction,the organic group of the organic azide molecules breaks with the Nα atom of the azide,and two activated products[L（η6-K）（THF）₂Mg（μ-N₃）Mg（THF）₂L]_∞（7）and[L（η6-K）Z（η-N₃）₂ZnL·K（THF）₆]_∞（8）bridged by the[N=N=N]-were obtained and characterized.