Skakle Janet M S, Tiekink Edward R T, Wardell James L, Wardell Solange M S V
Acta Crystallogr Sect E Struct Rep Online. 2009 Dec 4;66(Pt 1):o45-6. doi: 10.1107/S160053680905137X.
In the title resonance conformer, C(15)H(12)ClNO(4), the central C-N bond [1.297 (2) Å] has considerable double-bond character and the N-O bond [1.3215 (18) Å] indicates formal negative charge on the oxygen atom. Considerable deviations from co-planarity are evident in the mol-ecule, with both benzene rings twisted out of the central C-C-N-C plane [the dihedral angle formed between the rings = 81.99 (8)°]. Similarly, the carboxylic acid residue occupies a position almost normal to the plane of the benzene ring to which it is connected [C-C-O-C torsion angle = -78.42 (17)°]. The most prominent inter-molecular inter-actions involve the carboxylic acid the N(+)-O(-) residues with the O-H⋯O hydrogen bonds leading to helical supra-molecular chains along the b axis. These chains are connected into layers via C-H⋯O(carbon-yl) inter-actions and the layers are consolidated into the crystal structure by C-H⋯Cl contacts.
在标题共振构象体C₁₅H₁₂ClNO₄中，中心C-N键[1.297 (2) Å]具有相当大的双键特征，而N-O键[1.3215 (18) Å]表明氧原子上带有形式负电荷。分子中明显存在与共平面性的较大偏差，两个苯环均扭曲出中心C-C-N-C平面[环之间形成的二面角 = 81.99 (8)°]。同样，羧酸残基占据与其相连的苯环平面几乎垂直的位置[C-C-O-C扭转角 = -78.42 (17)°]。最显著的分子间相互作用涉及羧酸的N⁺-O⁻残基，通过O-H⋯O氢键形成沿b轴的螺旋超分子链。这些链通过C-H⋯O(羰基)相互作用连接成层，并且这些层通过C-H⋯Cl接触巩固成晶体结构。
