The synthesis, spectra, thermal study and crystal structure of a mixed ligand copper(II) compound viz. [Cu(biq)(acac)(NO₃)] 1 (biq = 2,2′-biquinoline, acac = acetylacetonate) are reported. The {CuN₂O₃} coordination sphere is made up of two oxygen atoms of an unique acac ligand, an oxygen of the nitrate group and one N atom of biq ligand which form the basal plane {CuNO₃} of a square pyramid. A second nitrogen atom of the biq ligand occupies the apical position resulting in a distorted square pyramidal {CuN₂O₃} polyhedron. In the crystal structure, each neutral square pyramidal copper(II) species is linked with two symmetry related molecules with the aid of intermolecular C-H^...O hydrogen bonding interactions. A study of fifteen mixed ligand copper(II) acetylacetonates reveals that in this series of compounds, 1 exhibits maximum deviation of the {CuN₂O₃} polyhedron from square pyramidal towards trigonal bipyramidal geometry.

中文翻译：

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扭曲的{CuN2O3}四方锥型混合配体铜（II）化合物的合成与结构

混合配体铜（II）化合物的合成，光谱，热研究和晶体结构。据报道[Cu（biq）（acac）（NO ₃）] 1（biq = 2,2'-联喹啉，acac =乙酰丙酮酸酯）。{CuN ₂ O ₃ }配位球由一个独特的acac配体的两个氧原子，一个硝酸盐基团的氧和一个biq配体的N个原子组成，它们构成方形金字塔的基面{CuNO ₃ }。biq配体的第二个氮原子占据顶端位置，导致扭曲的方形锥体{CuN ₂ O ₃}多面体。在晶体结构中，每个中性方形锥体铜（II）物种借助分子间CH ^... O氢键相互作用与两个对称相关的分子连接。十五种混合配体乙酰丙酮铜（II）的研究表明，在这一系列化合物中，1表现出{CuN ₂ O ₃ }多面体从方形锥体向三角形双锥体几何结构的最大偏离。