J. Janczak, R. Kubiak
2003
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Influential Citations
6
Citations
Journal
Journal of Molecular Structure
Abstract
Abstract The crystals of 3-cyanobenzamide have been obtained in the reaction of MgPcH 2 O with 1,3-dicyanobenzene. 3-Cyanobenzamide crystallises in the P 2 1 / c space group of the monoclinic system with four molecules per unit cell. In the crystal, the 3-cyanobenzamide molecule is non-planar, the amide group is rotated by 21.8(1)° around the C ar –C sp 2 bond in relation to the phenyl ring. Full optimised molecular orbital calculations performed on the isolated 3-cyanobenzamide molecule have shown a similar conformation (the rotation angle equals to 22.46°). Two pairs of symmetric equivalent N–H⋯O and N–H⋯N hydrogen bonds with two neighbouring form pseudo one-dimensional chains interconnect each 3-cyanobenzamide molecule in the crystal. The chains of 3-cyanobenzamide molecules form a stacking structure with π⋯π interactions between the aromatic phenyl rings within the stacks. The molecular orbital calculations and conformational analysis have shown two equivalent pairs minimum of energy on the potential energy surface (PES)—one global, other local. During rotation of the amide group from 0 to 360° around the C ar –C sp 2 bond four rotation barriers are observed. The highest rotation barrier energy of 48.84 kJ mol −1 is compared to the hydrogen bond energy.