title: Metal phosphonates based on (4-carboxypiperidyl)-N-methylenephosphonate: in situ ligand cleavage and metamagnetism in Co3(O3PCH2-NHC5H9-COO)2(O3PCH2-NC5H10)(H2O).
abstract: Hydrothermal reaction of (4-carboxypiperidyl)-N-methylenephosphonic acid (4-cpmpH3) and zinc sulfate results in compound Zn(O3PCH2-NHC5H9-COO) (). It has a pillared layered structure in which the inorganic layers made up of corner-sharing {CPO3} and {ZnO4} tetrahedra are connected by the organic groups. When cobalt sulfate is allowed to react with 4-cpmpH3 under similar conditions, a proportion of the ligands undergo decarboxylation, leading to the formation of a novel mixed ligated compound Co3(O3PCH2-NHC5H9-COO)2(O3PCH2-NC5H10)(H2O) (). Compound also shows a pillared layered structure with the topology of the inorganic layer similar to that of . The CoII ions in are all tetrahedrally coordinated. Significant difference between the two structures lies in the packing of the layers, e.g....AAA... in while ...AABAAB... in . More interestingly, compound behaves as a metamagnet at low temperature. The critical field is 40.1 kOe at 1.8 K.
authors.affiliation: State Key Laboratory of Coordination Chemistry, Coordination Chemistry Institute, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, PR China.
authors.forename: Shou-Zeng
authors.initials: SZ
authors.lastname: Hou
authors.forename: Deng-Ke
authors.initials: DK
authors.lastname: Cao
authors.forename: Xun-Gao
authors.initials: XG
authors.lastname: Liu
authors.forename: Yi-Zhi
authors.initials: YZ
authors.lastname: Li
authors.forename: Li-Min
authors.initials: LM
authors.lastname: Zheng