• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.374-378
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• 2013

Two novel binuclear metal-organic coordination complexes [$Cd_2(Hdpa)_4(bpy)_2$] (1), [$Dy_2(dpa)_2(bpy)_2(NO_3)_2-(H_2O)_2$](bpy) (2) (where $H_2dpa$ = biphenyl-2,2'-dicarboxylic acid, bpy = 2,2'-bipyridine) have been synthesized under hydrothermal conditions and characterized by single crystal X-ray diffraction, spectral method (IR), elemental analysis (EA), powder X-ray diffraction (XRD), electronic spectra (UV-vis), fluorescent in the solid state and thermogravimetric analysis (TGA). Complexes 1-2 crystallizes isomorphously in the Triclinic space group P-1. The ${\pi}-{\pi}$ stacking interactions and hydrogen-bonds play a vital role in determining the crystal packing and construction of the extended 3-D supramolecular network.

• Applied Chemistry for Engineering
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• v.3 no.2
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• pp.280-287
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• 1992

Aromatic liquid crystalline polyesters were synthesized from terephthalic acid(TPA), biphenyl dicarboxylic acid(BPA) and hydroquinone(HQ) by solution polymerization. Effects of TPA/BPA ratio(by mole %) on the thermal properties, thermal stability and textures of mesophases were investigated with DSC, TGA, cross-polarized microscopy and X-ray diffractometer. The synthesized polymers in this study were thermotropic and showed nematic textures. Melting temperature($T_m$) and isotropization temperature($T_i$) of polymer increased and thermal stabilities of polymer were improved with the content of BPA. Most of the polymers in this study had crystallinity more than 30%.