title: Metal phosphonates based on bis(benzimidazol-2-ylmethyl)imino methylenephosphonate: from discrete dimer to two-dimensional network containing metallomacrocycles.
abstract: Hydrothermal reactions of bis(benzimidazol-2-ylmethyl)imino(methylenephosphonic acid) {[(C(7)H(5)N(2))CH(2)]2NCH(2)PO(3)H(2), bbimpH2} with metal salts result in four new compounds, namely, Mn2{[(C(7)H(5)N(2))CH2]2NCH(2)PO(3)}2(H2O)2.2H2O (1), Cd2{[(C(7)H(5)N(2))CH2]2NCH(2)PO(3)}2.2H2O (2), Fe2{[(C(7)H(5)N(2))CH2]2NCH(2)PO(3)}2.H2O (3), and CuI(2){[(C(7)H(5)N(2))CH2]2NCH(2)P(OH)O2}2 (4). Compounds 1 and 2 have dinuclear structures in which two {MN(3)O(3)} octahedra are linked through edge sharing. In compound 3, a chain structure is observed where the {FeN(3)O(2)} trigonal bipyramids are linked by {CPO(3)} tetrahedra through corner-sharing. The structure of compound 4 is unique. The monovalent Cu(I) ions are connected by the imidazole nitrogen atoms from the bbimp(2-) ligands forming a 16-member metallomacrocycle. These metallomacrocycles are further connected by the phosphonate oxygen atoms, leading to a two-dimensional net containing 16- and 32-member rings. Magnetic studies of 1 and 3 reveal that weak ferromagnetic interactions are mediated between magnetic centers in compound 1, while antiferromagnetic interactions were observed in compound 3.
authors.affiliation: State Key Laboratory of Coordination Chemistry, Coordination Chemistry Institute, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China.
authors.forename: Deng-Ke
authors.initials: DK
authors.lastname: Cao
authors.forename: Jing
authors.initials: J
authors.lastname: Xiao
authors.forename: Jian-Wei
authors.initials: JW
authors.lastname: Tong
authors.forename: Yi-Zhi
authors.initials: YZ
authors.lastname: Li
authors.forename: Li-Min
authors.initials: LM
authors.lastname: Zheng