Das Birinchi K, Bora Sanchay J, Bhattacharyya Manjit K, Barman Rama K
Department of Chemistry, Gauhati University, Guwahati 781 014, Assam, India.
Acta Crystallogr B. 2009 Aug;65(Pt 4):467-73. doi: 10.1107/S0108768109021090. Epub 2009 Jul 11.
Two new metal compounds of the formula [M(H(2)O)(3)(SO(4))(4-CNpy)(2)] x H(2)O [M = Ni (1) and Co (2), 4-CNpy = 4-cyanopyridine] have been prepared and studied by X-ray diffraction. In both of these compounds the 4-CNpy ligands are coordinated via pyridyl-N atoms to the metal ions in a cis fashion. The neutral complexes along with the uncoordinated H(2)O molecules are glued together preferentially into inverse bilayers by non-covalent interactions, including unique interlayer pi-pi interactions between antiparallel nitrile groups. Hartree-Fock and density-functional theory (DFT) calculations indicate that the pi-pi interactions are energetically significant. The unit-cell similarity index (Pi) of 0.0046 for the compounds suggests their isostructurality, which is also supported by their X-ray powder diffraction patterns that can be almost superimposed.
已经制备了两种新的通式为[M(H₂O)₃(SO₄)(4-CNpy)₂]·H₂O的金属化合物[M = Ni (1) 和Co (2)，4-CNpy = 4-氰基吡啶]，并通过X射线衍射进行了研究。在这两种化合物中，4-CNpy配体均通过吡啶基-N原子以顺式与金属离子配位。中性配合物与未配位的H₂O分子通过非共价相互作用优先粘结在一起形成反相双层，包括反平行腈基之间独特的层间π-π相互作用。Hartree-Fock和密度泛函理论（DFT）计算表明，π-π相互作用在能量上具有重要意义。化合物的晶胞相似指数（Pi）为0.0046，表明它们具有同构性，这也得到了它们几乎可以叠加的X射线粉末衍射图谱的支持。
