TY - JOUR
T1 - Synthesis, structure, topology and magnetic properties of cobalt(ii) coordination polymers with 2-nitrobiphenyl-4,4′-dicarboxylic acid and bis(pyridyl) ligands
AU - Jing, Xue Hui
AU - Yi, Xiu Chun
AU - Gao, En Qing
AU - Blatov, Vladislav A.
PY - 2012/11/12
Y1 - 2012/11/12
N2 - Four coordination polymers, [Co2(Hnbpdc)2(nbpdc)(bipy)2]n (1), [Co3(nbpdc)3(bipy)3(H2O)2]n·2nH2O (2), [Co4(nbpdc)4(bipy)(H2O)4]n (3), and [Co2(nbpdc)2(bpee)3/2]n·0.25nH2O (4) [H2nbpdc = 2-nitrobiphenyl-4,4′-dicarboxylic acid, bipy = 4,4′-bipyridine and bpee = 1,2-di(4-pyridyl)ethane] have been synthesized by hydrothermal methods and studied by means of X-ray crystallography, topological analyses and magnetic analyses. Compounds 1–3 were synthesized from the same reactants under controlled conditions (pH and ligand ratio). Compounds 1, 2 and 4 contain bis(carboxylate)-bridged dinuclear motifs as secondary building units (SBUs). In 1 and 2 the SBUs are connected into 44 layers by bis(chelating) nbpdc and pairwise bipy linkers. In 1, the layers are pillared into a 3D framework with the pcu topology by Hnbpdc, which is coordinated to one layer and hydrogen-bonded to another layer. In 2, the layers and the linear [Co(bipy)]n chains intercalated between the layers are connected by nbpdc to produce a 3D framework exhibiting a rarely observed 4,6-connected topology. In 4 the SBUs are connected by nbpdc [bis(chelating) and bis(bridging)] and bpee (single and pairwise) to yield a 3D framework, which defines a new 6-connected net with point symbol (410 ·52 ·63). Notably, this new net and the known hex-6-P6222 net represent the first examples of topologically different nets having the same coordination sequences, point and vertex symbols. Compound 3 contains carboxylate- and aqua-bridged tetranuclear motifs as SBUs, which are connected by covalent linkers (nbpdc and bipy) and sextuple O–H⋯O hydrogen bonds to generate a 3D framework, which defines a new 10-connected net with point symbol (424 ·512 ·68 ·7) (considering only covalent linkers) and a new 12-connected net with point symbol (312 ·436 ·517 ·6) (including also the hydrogen bonds as linkers). Magnetic studies on 1 and 2 demonstrated that the bis(syn–skew-carboxylate) bridges between octahedral Co(ii) ions induce ferromagnetic coupling; 4 is peculiar in that octahedral and tetrahedral Co(ii) ions are linked by mixed syn–syn and syn–skew carboxylate bridges, which give rise to antiferromagnetic coupling.
AB - Four coordination polymers, [Co2(Hnbpdc)2(nbpdc)(bipy)2]n (1), [Co3(nbpdc)3(bipy)3(H2O)2]n·2nH2O (2), [Co4(nbpdc)4(bipy)(H2O)4]n (3), and [Co2(nbpdc)2(bpee)3/2]n·0.25nH2O (4) [H2nbpdc = 2-nitrobiphenyl-4,4′-dicarboxylic acid, bipy = 4,4′-bipyridine and bpee = 1,2-di(4-pyridyl)ethane] have been synthesized by hydrothermal methods and studied by means of X-ray crystallography, topological analyses and magnetic analyses. Compounds 1–3 were synthesized from the same reactants under controlled conditions (pH and ligand ratio). Compounds 1, 2 and 4 contain bis(carboxylate)-bridged dinuclear motifs as secondary building units (SBUs). In 1 and 2 the SBUs are connected into 44 layers by bis(chelating) nbpdc and pairwise bipy linkers. In 1, the layers are pillared into a 3D framework with the pcu topology by Hnbpdc, which is coordinated to one layer and hydrogen-bonded to another layer. In 2, the layers and the linear [Co(bipy)]n chains intercalated between the layers are connected by nbpdc to produce a 3D framework exhibiting a rarely observed 4,6-connected topology. In 4 the SBUs are connected by nbpdc [bis(chelating) and bis(bridging)] and bpee (single and pairwise) to yield a 3D framework, which defines a new 6-connected net with point symbol (410 ·52 ·63). Notably, this new net and the known hex-6-P6222 net represent the first examples of topologically different nets having the same coordination sequences, point and vertex symbols. Compound 3 contains carboxylate- and aqua-bridged tetranuclear motifs as SBUs, which are connected by covalent linkers (nbpdc and bipy) and sextuple O–H⋯O hydrogen bonds to generate a 3D framework, which defines a new 10-connected net with point symbol (424 ·512 ·68 ·7) (considering only covalent linkers) and a new 12-connected net with point symbol (312 ·436 ·517 ·6) (including also the hydrogen bonds as linkers). Magnetic studies on 1 and 2 demonstrated that the bis(syn–skew-carboxylate) bridges between octahedral Co(ii) ions induce ferromagnetic coupling; 4 is peculiar in that octahedral and tetrahedral Co(ii) ions are linked by mixed syn–syn and syn–skew carboxylate bridges, which give rise to antiferromagnetic coupling.
UR - https://www.scopus.com/pages/publications/84870844269
U2 - 10.1039/c2dt31917a
DO - 10.1039/c2dt31917a
M3 - 文章
AN - SCOPUS:84870844269
SN - 1470-479X
VL - 41
SP - 14316
EP - 14328
JO - Journal of the Chemical Society. Dalton Transactions
JF - Journal of the Chemical Society. Dalton Transactions
IS - 47
ER -