Analytical Sciences

Abstract − Analytical Sciences, 19(3), 469 (2003).

Crystal Structure of 4,5-Bis(4-dimethylaminophenyl)-2-(4-nitrophenyl)imidazole
Xiu R. BU,*  Donald VANDERVEER,** Javier SANTOS,* Fu-Lian HSU,*** Jie WANG,* and Kofi BOTA*
*Department of Chemistry & NASA Center for High Performance Polymers and Composites, Clark Atlanta University, Atlanta, GA 30314, USA
**School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA
***US Army Edgewood Chemical and Biological Center, Aberdeen Proving Ground, MD 21010, USA
A nonlinear optical chromophore, 4,5-bis(4-dimethylaminophenyl)-2-(4-nitrophenyl)imidazole, was investigated by X-ray crystallography. The study focused on coplanarity among several aromatic rings, including phenyls and imidazole. Two phenyl rings with NMe2 groups are twisted by 46.39(3)° from each other. However, they are twisted by 23.05(5)° and 46.84(3)° from the imidazole, respectively. These unequal twists were elucidated by different conjugation pathways from the donors to the acceptor. The phenyl ring with the NO2 group is twisted by only 6.76(6)° from the imidazole.