Synthesis, structures and properties of novel metallophosphazenes

Abstract

Inorganic heterocyclic or chain compounds containing alternate phosphorus and nitrogen atoms, phosphazenes, have been attracting widespread attention which are unique carriers for transition metals owing to their ability to serve as versatile multifuntional ligands and templates. The type of side groups attached to the phosphazene chain and transition metals have a powerful effects on the physical and chemical characteristics. Special chemical and physical properties of synthetic macromolecules may provide a vehicle for important advances in catalysts, in chemotherapy, and the understanding of chemical and biological reaction mechanism. In this thesis, the new synthetic routes to several types of novel metalloposphazene using hexakis(pyrazolyl) cyclotriphosphazene (1), hexakis(benzotriazolyl)cyclotriphosphazene (2) and kexakis(3,5-dimethylpyrazolyl)-cyclotriphosphazene (3) as ligands were presented. In addition, the full characterizations including single crystal X-ray diffraction studies and the measurements of physical properties were carried out. Neutral metallophosphazenes are divided into three kinds of mono-, homodinuclear and heterodinuclear complexes. Mono- and homodinuclear complexes $[3ㆍ(MCl_2)_m]$ (M=Hg, m=1; 5, M=Cd, m=2; 6) were synthsized from the methylene dichloride reaction systems of 3 with three amounts of $MCl_2$. On the other hand, the equimolar reactions of 3 with mixed metal halides or cabonyls, MXn and M``X``m, in methylene dichloride afforded a set of new heterodinuclear metallophosphazenes [$X_nㆍM(μ-3)ㆍM``X``_m$] ($MX_n= ZnCl_2$, $M``X``_m= CuI ; 7$, $MX_n= MnCl_2$, $M``X``_m= CuI ; 8$, $MX_n= CoCl_2$, $M``X``_m= CuI ; 9$, $MX_n= CoCl_2$, $M``X``_m= ZnCl_2 ; 10$, $MX_n= CoCl_2$, $M``X``_m= Mo(CO)_3 ; 11$). Heteroleptic sandwich type of ionic metallophosphazenes [$Cp*Mㆍ3$]$(BPh_4)_2$ {M = Rh (14), Ir (15); $Cp^*$ = pentamethylcyclopentadienyl} were prepared from the acetonitrile reaction systems of 3/[$Cp^*M(NCCH_3)_3$]$(ClO4)_2$/ $NaBP...