title: Phosphonates containing 8-hydroxyquinoline moiety and their metal complexes: structures, fluorescent and magnetic properties.
abstract: Two kinds of solid-state structures of 5-phosphonomethyl-8-hydroxyquinoline (5pm8hqH3) have been obtained, namely 1·HCl·H2O and 1·H2O, involving different hydrogen bonds and/or aromatic stacking interactions. As a derivative of 5pm8hqH3, 5-phosphonomethyl-8-(carboxymethoxy)quinoline (5pm8cmoqH3) was synthesized. Based on 5pm8hqH3 and 5pm8cmoqH3, three new metal phosphonates have been hydrothermally prepared, including Zn(5pm8hqH)(H2O)·H2O (2), Cu(5pm8cmoqH)·2H2O (3) and Fe(5pm8cmoqH) (4), exhibiting layered structures for 2 and 4, and a three-dimensional open framework for 3. The 8-hydroxyquinoline moieties in 1·H2O and 2-4 exhibit three kinds of interesting aromatic stacking modes, including pyridine ring-pyridine ring stacking between a pair of moieties, double benzene ring-pyridine ring stacking between a pair of moieties and alternating benzene ring-benzene ring and pyridine ring-pyridine ring stacking among a number of moieties in the layered structure. The solid-state fluorescence measurements indicate the emissions of 1·HCl·H2O and 1·H2O are significantly different due to their distinct packing structures. Compound 2 exhibits both ligand-centered (LC) and ligand-to-metal charge transition (LMCT) emissions. Magnetic studies reveal dominant antiferromagnetic interactions in 3 and 4.
authors.affiliation: State Key Laboratory of Coordination Chemistry, Coordination Chemistry Institute, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China. dkcao@nju.edu.cn
authors.forename: Deng-Ke
authors.initials: DK
authors.lastname: Cao
authors.forename: Bei
authors.initials: B
authors.lastname: Liu
authors.forename: Yan-Wei
authors.initials: YW
authors.lastname: Gu
authors.forename: Jia-Qi
authors.initials: JQ
authors.lastname: Feng
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006912:Hydroxyquinolines / Q000737:chemistry*; D008280:Magnetics; D008670:Metals / Q000737:chemistry*; D008968:Molecular Conformation; D063065:Organophosphonates / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D056831:Coordination Complexes; D006912:Hydroxyquinolines; D008670:Metals; D063065:Organophosphonates