| Summary: | 碩士 === 國立臺北科技大學 === 有機高分子研究所 === 97 === The synthesis, structural characterization and thermal stability of five metal-organic coordination compounds by metal ions (M = Mn2+ and Cd2+) with bipyridine-type ligands of 3-bpd (1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene), dpe (1,2-bis(4-pyridylethane)) or bpe (1,2-bis(4-pyridylethylene)) are studied. The first part concerns two Mn(II) complexes of [Mn(mu2-3-bpd)2(NCS)2(H2O)2].2H2O (1) and {[Mn(mu2-bpe)(NCS)2(H2O)2].(3-bpd).(bpe).H2O}n (2), while the second part contains three Cd(II) coordination polymers of {[Cd(mu2-3-bpd)2(NCS)2].C2H5OH}n (3), {[Cd(mu2-3-bpd)(mu2-dpe)(NO3)2].(3-bpd)}n (4), {[Cd(mu2-dpe)2(NCS)2].3-bpd.2H2O}n (5). All of them were prepared in solution and fully characterized by elemental analysis, Infrared Spectroscopy, thermogravimetric analysis, and single-crystal X-ray diffraction. Structural determination reveals that the coordination geometry at Mn(II) in compounds 1 or 2 is a distorted octahedral which consists of two nitrogen donors from NCS- ligands, two oxygen donors from water molecules, and two nitrogen donors from 3-bpd ligands for 1 and two bpe ligands for 2, respectively. Two 3-bpd ligands in 1 adopt a monodentate binding mode and the bpe in 2 adopts a bis-monodentate bridging mode to connect the Mn(II) ions forming a 1D chain-like coordination polymer. Both thepi-pi stacking interactions and intermolecular hydrogen bonds among the ligands and solvent molecules do play important roles in construction the 3D supramolecular architectures.
In compound 3, each Cd(II) ion is six-coordinated by six nitrogen donors from four 3-bpd with a bis-monodentate coordination mode and two NCS- ligands. The distorted square building blocks connect each other to generate a 2D non-interpenetrating MOF. Each square unit consists of four Cd(II) atoms and 3-bpd ligands, which form a 44-membered ring structure. In 4, the Cd(II) ion is six-coordinated by six nitrogen donors from two 3-bpd, two dpe and two NO32-ligands. Both the 3-bpd and dpe ligands adopt a bis-monodentate coordination mode to connect the Cd(II) ions forming a 2D, non-interpenetrating parallelogram MOF. Each parallelogram unit consists of four Cd(II) atoms, two 3-bpd ligands and two dpe, which also form a 44-membered ring structure. In 5, the Cd(II) ions is coordinated by four pyridine nitrogen donors of dpe ligands in the basal plane and two NCS- nitrogen donors in the axial sites. The dpe acts as a bridging ligand to connect the Cd(II) ions forming a 2D interpenetrating MOFs by using a square-planar node as the basic unit, which also form a 44-membered ring structure. The free 3-bpd ligands in 4 and 5 play an important role on the construction of their 3D supramolecular architecture via the pi-pi stacking interactions.
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