Syntheses, Structures And Properties Of Hybird Organic-inorganic Materials Based On Metal Phosphonates

Metal phosphonates as a class off inorganic-organic hybridmaterials have attracted a great deal of research interest as aresult of their ability to form interesting structures with potentialapplications as catalysts,ion exchangers, sensors9sorbents andnonlinear optics materials. Number of phosphonategroups, presenceofotherfunctionalmoieties:carboxylate9sulfonafe9amine9hydfoxyLAmong thesestudiosythe phosphonic acids with hydroxyl and carboxyl groupsas ligands could provide many coordination modes, resulting invarious interesting structures. By using2-hydroxylphosphonoaceticacid with a chiral carbon atom and three functional groups(-OH,-COOH and-P03H2)，we report six metal phosphonates In thispaper. Another two complexes have been synthesized in thedissertation by hyd『o(solvo)the『mal in situ ligand synthesismethods.This dissertation is consist of four chapters.Initially9chapter1is a brief introduction to inorganic-organichybrid materials and solvothermal methed，then the recentadvances on syntheses， structures and properties of metalphosphonates. Six complexes have been obtained by2-hydroxylphosphonoacetic acid, the transition metal (Co2+, Mn2+and Zn2+) and other co-ligand under hydrothermal reaction in chapter2. In compound1, trimer Co clusters are linked with neighbours via organic ligands to form3D framework, in which a fraction of C atoms are disordered. Compound2also possess3D framework with petaline-like motif. In compound3the pyridine co-ligands are disordered. Compound1and3exhibit unusual ferrimagnetic coupling but2display spin-canting antiferromagnetic behaviour. Compound4-5are2D and3D framework structure,show strong antiferromagnetic coupling.Compounds6has three-dimensional open microporous framework structure with a one-dimensional consisting of interconnected24-atcm channels system along the a-axis and show strong blue fluorescence.By using2-pinosphonopropionic acid triethylester two complexes have been synthesized in chapter3in situ hydrothermal reaction.We choosed Co2+and Cu2+as start materials and sythetizad two new metal phcsphonates,[Co3(MePO3CHC02)2(H20)2](7),and[Cu2(MeP03COC02)(o H)0.5(bpa)](8). The structure of compound7comprises Coo6polyhedra linked to each other by to form infinite Co-O chains, and each chains are bridged by the CPO3tetraheda into a Coll phosphonate layer in ab-plane,7presents spin-canting antiferromagnetis. Compound8has been synthesized by hydro(solvo)thermal in situ ligand synthesis methods. The structure of compound8exhibits a complex three-dimensional (3D) open framework structure with a one-dimensional channel system along the b-axis and exhibits paramagnetic behaviour.Chapter4is a conclusion.