Somphon Weenawan, Haller Kenneth J, Rae A David, Ng Seik Weng
School of Chemistry, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand.
Acta Crystallogr B. 2006 Apr;62(Pt 2):255-61. doi: 10.1107/S0108768106002461. Epub 2006 Mar 15.
The 1:1 adduct of [SnCl2(C2H4COOCH3)2] and 1,10-phenanthroline, (C12H8N2), which was set aside for 25 years, when recrystallized from ethanol was found to be the salt [C12H9N2]+.[SnCl2(C2H4COO)(C2H4COOH)]-. The Sn(IV) atom in the anion has pseudo-octahedral coordination with two cis Cl atoms, two C atoms and two O atoms trans to the Cl atoms. The possibility of alternative stacking of layers perpendicular to c* offers an explanation for observed twinning and polytypism. An ordered, untwinned, Z = 2 crystal structure was determined. Pairs of adjacent anions are linked together by strong intermolecular O-H...O- hydrogen bonds, and the cation contains a strong intramolecular N-H...N hydrogen bond between its two N atoms. The protonated ring of the cation exhibits increased Lewis acidity and is linked into a network with the anions using a strong N-H...O and weak C-H...O and C-H...Cl interactions. The remaining rings of the cation form weaker C-H...O and C-H...Cl interactions. The cations stack in columns along a with an interplanar spacing of 3.24 angstroms for separations between cations inversion-related about (1, 1/2, 1/2) and 3.34 angstroms for separations between cations inversion-related about (1/2, 1/2, 1/2).
[SnCl₂(C₂H₄COOCH₃)₂]与1,10 - 菲咯啉（C₁₂H₈N₂）的1:1加合物，放置25年后，当从乙醇中重结晶时，发现是盐[C₁₂H₉N₂]⁺·[SnCl₂(C₂H₄COO)(C₂H₄COOH)]⁻。阴离子中的Sn(IV)原子具有假八面体配位，有两个顺式Cl原子、两个C原子以及两个与Cl原子呈反位的O原子。垂直于c*的层存在交替堆积的可能性，这为观察到的孪晶和多型性提供了解释。确定了一个有序、无孪晶、Z = 2的晶体结构。相邻阴离子对通过强分子间O - H...O氢键连接在一起，阳离子在其两个N原子之间含有强分子内N - H...N氢键。阳离子的质子化环表现出增强的路易斯酸性，并通过强N - H...O以及弱C - H...O和C - H...Cl相互作用与阴离子连接成网络。阳离子的其余环形成较弱的C - H...O和C - H...Cl相互作用。阳离子沿a轴堆积成列，对于与(1, 1/2, 1/2)呈反演关系的阳离子之间的间距，面间距为3.24埃；对于与(1/2, 1/2, 1/2)呈反演关系的阳离子之间的间距，面间距为3.34埃。
