C-H…O Hydrogen Bonds and π…π Interaction and the Crystal and Molecular Structures of 3-Nitro-benzylideneaniline-methyl-2’

The title compound (C14H12N2O2, Mr = 240.26) crystallizes in the monoclinic system, space group P21/a with a = 7.394(1), b = 21.334(3), c = 7.423(1) ? b = 89.82(1)? V = 1170.8(3) ?, Z = 4, Dc = 1.363 g/cm3, m(MoKa) = 0.93 cm-1 and F(000) = 504.00. The final R and wR are 0.0440 and 0.1370 for 2153 observed reflections (I > 2s(I)), respectively. The dihedral angle between the two phenyl rings is 52.9 and that between the NO2 group and its attached ring is 3.0. In the crystal, molecules are stacked along [100] through p…p interactions. The CH…O hydrogen bond (3.403 ? 120.4? laterally connects the stacks along [010] to form networks (001) which are further anti- parallelly connected by CH…O (3.382 ? 142.9) and p…p interactions extending along [001]. Also presented here is a brief study on the CH…O hydrogen bonds in nitro-substituted benzyl-ideneanilines which can be classified into five types, namely, )5(12R, )4(21R, )8(22R, )6(12R and )7(22R, with the first three occurring more often.

HXeBr与苯和苯的衍生物弱相互作用的理论研究

采用MP2/aug-cc-p VDZ(对于Xe和I原子采用aug-cc-p VDZ-PP基组)优化了复合物HXe Br…C_6H_5X(X=H,CH_3,NH_2,N(CH_3)_2,NHCH_3,OH,OCH_3,CN,F,Cl,Br,I,COOH,SO_3H,CF3)及单体的几何构型,详细分析了π…H键和双齿氢键两种弱相互作用类型的特征,以及不同的取代基对这两种弱相互作用能的影响.对14个双齿氢键型复合物,我们发现复合物的相互作用能与苯环衍生物(C_6H_5X)的偶极矩,复合物中Xe—Br键键长的变化,H—Xe键键长的变化和H—Xe键振动频率的变化,以及双齿氢键上Br原子和两个H原子范德华表面相互穿透距离之和均有较好的线性关系.另外,我们还发现复合物的相互作用能与双齿氢键上两个键临界点的电子密度之和,电子密度Laplacian值之和,静电势之和,以及双齿氢键和苯环碳原子形成环的环临界点处的电子密度,电子密度Laplacian值以及静电势均有着较好的线性关系.