Synthesis Of Heavier Carbene Stabilized By Novel ?-diketimine

The synthesis of heavier carbene compounds is a rapidly developing field in inorganic synthesis chemistry in the last thirty years.These low-valent heavier group elemental compounds not only have novel structures,but also can be used as ligands for synthesis of heavier group atoms and transition metals in d and f regions.At present,there have been considerable achievements in heavier carbene and its coordination chemistry,which not only enriched the basic theory of chemistry and deepened people's cognition of material structure,but also revealed the physical properties of single-molecule magnets by studying the magnetic properties of these semi-metal-metal complexes.Therefore,the synthesis and characterization of the structure and magnetic properties of such molecules,and the theoretical interpretation of them,has become a very prospective research work in the field of inorganic synthesis,but also a very challenging subject.In this master's project,?-diimines were selected as ligands to explore their assembly with B,Ga,Si and Ge,in an attempt to find a series of heavier carbene molecules with more novel structures,laying a foundation for the further study of their coordination chemistry with transition metals.This master's work is mainly divided into the following parts:1.The synthesis of a series of complex B,Ga,Si and Ge was investigated using new type?-diimine 1.(1)Reducing?-diimine chlorinated germanium carbene 3 by tri-sec-butyl borohydride(K[BH(^sBu)₃]),we can successfully obtained?-diimine germylene 4.Compound4 is the first pentacyclic germylene isolated by a special reduction method.Its divalent germanium atoms are in a stable pentacyclic aromatic ring.The successful separation of the main group element from the transition metal provides a new heavier carbene ligand.(2)Compound 11 containing Ga=Ga double bond was successfully obtained by reducing?-diimide gallium chloride complex 9 with potassium metal.In compound 11,Ga=Ga bond length is 2.370?,which is the compound with the shortest Ga=Ga double bond found so far,which is an important contribution to the enrichment of unsaturated compounds of group 13 elements.2.On the basis of the previous unfinished work on the synthesis of B=O double bond,a new method was used to separate hydroxyborane 16 and oxoborane 17 with high yield and purity,and complete structural characterization was carried out.Compound 17 is a new type compound containing B=O double bond stabilized by?-diketiminate with a bond length of 1.301?for B=O.In this molecule,the anion of borane oxide interacts with the cation of imidazole by hydrogen bond.3.The reactivity of?-diketiminate free radical germanium carbine 18 was tested by CoBr₂,and?-diketiminate bromide germanium carbine 19 was isolated.The reactivity experiment showed that the free radical germylene 18 could be oxidized even when it encountered weak oxidizing metal ions.4.Three novel novel?-diketiminate ligands 22,25,and 28 have been explored and developed by means of carbon-carbon coupling.All three ligand nitrogen atoms are connected with steric hindrance substituents,which have unique space protection effect.The ligand's double nitrogen chelation effect and electron conjugation effect are thermodynamic stabilization effects.Therefore,they can be used to synthesize many novel main group elements complexes,which is an important basis for further research.To sum up,this master's work in the planning of subject within the scope of successful characterization in group of 17 cases of new compounds,has accumulated rich experience in anaerobic synthetic anhydrous,low coordination and low state main group elements made certain contribution to synthetic chemistry,to continue to explore next heavy carving coordination chemistry created favorable prospect.