A new 1D chain coordination polymer [Cd(dpq)(ox)0.5Cl]n (1) (dpq=dipyrido[3,2-d:2′,3′-f]quinoxaline and ox=oxalate) has been hydrothermally synthesized and structurally characterized by elemental analysis, IR and single crystal X-ray diffraction analysis. Compound 1 (CdClC15H8N4O2): monoclinic, space group P21/c, a=0.854 04(5) nm, b=2.094 90(13) nm, c=0.839 22(5) nm, Z=4, V=1.438(15) nm3, Mr=424.11, Dc=1.959 g·cm-3, F(000)=828.0, μ= 1.719 mm-1, S=1.028, the final R=0.025 8 and wR=0.057 5. The crystal structure analysis indicates that the cadmium ion is coordinated by two oxygen atoms from a oxalate, two chelating nitrogen atoms from a dpq molecule and two Cl-anions. The adjacent Cd(Ⅱ) ions are linked by Cl-anions and oxalate ligands in alternate sequence to form a 1D chain coordination polymer and the adjacent chains are further connected by π-π stacking interactions to form a 2D supramolecular network. Moreover, the title compound exhibits blue emission in the solid state at room temperature.
Four coordination polymers based on two bis-pyridyl-bis-amide ligands and three aromatic dicarboxylates with different substituent groups, namely, [Co(3-bpcb) 1.5 (NPH)(H2O)]·4H2O (1), [Co(3-bpcb)(NIPH)] (2), [Co(3-bpcb)0.5 (5-H2 AIP)]·2H2O (3), [Co(3-bpcd) 0.5 (5-H2 AIP)(H2O)]·2H2O (4) [3-bpcb = N,N′-bis(3-pyridinecarboxamide)-1,4-benzene, 3-bpcd = N,N′-bis(3- pyridine)cyclohexane-1,4-dicarboxamide, H2 NPH = 3-nitrophthalic acid, H2 NIPH = 5-nitroisophthalic acid, 5-H4 AIP = 5-aminoisophthalic acid] have been synthetized under hydrothermal conditions. Complex 1 displays a one dimensional (1D) chain based on the binuclear [Co2 (NPH)2 ] units and 3-bpcb ligands, which is extended into a three dimensional (3D) supramolecular framework through hydrogen bonding and - stacking interactions. In complex 2, the (3,5)-connected two dimensional (2D) layers are constructed from 1D Co-NIPH chains and bidentate-bridging 3-bpcb ligands. Complex 3 is a 2D double layer based on Co-5-H2 AIP 2D layers and 3-bpcb pillars. Complex 4 also displays a 2D network, which is constructed from the Co-5-H2AIP 1D double chains and 3-bpcd ligands. Finally, complexes 2-4 are extended into 3D supramolecular frameworks by hydrogen bonding or - stacking interactions. The substituent groups of dicarboxylates play an important role in the assembly and structures of the title complexes. In addition, the fluorescent properties of complexes 1-4 and the electrochemical behaviors of 3 and 4 at room temperature have been investigated.
WANG XiuLiMU BaoLIN HongYanYANG SongLIU GuoChengTIAN AiXiangZHANG JuWen
