期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1970
卷号：67
期号：1
页码：426-433
DOI：10.1073/pnas.67.1.426
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：N,N'-diphenyl-N,N'-diethylurea (C17H20N2O) crystallizes in the space group P21/c. The unit cell constants are: a = 10.42 {+/-} 0.01 A, b = 16.86 {+/-} 0.02 A, c = 10.66 {+/-} 0.001 A, {beta} = 125{degrees}16' {+/-} 5'; Z = 4, Dx = 1.16 g{middle dot}cm-3, Dmeas = 1.16 {+/-} 0.01 g{middle dot}cm-3. Data for 1392 reflections were collected at room temperature on a Picker automated diffractometer. The crystal structure was solved by direct methods and refined by bloc-diagonalized matrix least-squares calculations. The molecule is characterized by a pseudo C2 symmetry; both phenyl groups are trans with respect to the oxygen atom. The hybridization of the two nitrogen atoms is intermediate between trigonal and tetrahedral; the nonplanar distortion of the amide groups is about 30{degrees}. The amide C-N bond lengths are 1.37 A.
