丙二酰胺（NH2C(O)-CH2-C(O)NH2）的互变异构和构象性质：电子衍射和量子化学研究

Tautomeric and conformational properties of malonamide, NH2C(O)-CH2-C(O)NH2: electron diffraction and quantum chemical study.

作者信息

Belova Natalya V, Oberhammer Heinz, Girichev Georgiy V, Shlykov Sergey A

机构信息

Ivanovo State University of Chemistry and Technology, Ivanovo 153460, Russia.

出版信息

J Phys Chem A. 2007 Mar 22;111(11):2248-52. doi: 10.1021/jp0686801. Epub 2007 Mar 1.

DOI:10.1021/jp0686801

PMID:17388304

Abstract

The geometric structure of malonamide, NH2C(O)-CH2-C(O)NH2, has been investigated by gas electron diffraction (GED) and quantum chemical calculations (B3LYP and MP2 approximations with 6-311++G(3df,pd) basis sets). Both GED and quantum chemistry result in the existence of a single diketo conformer in the gas phase. According to GED refinement this conformer possesses (sc,ac) conformation with one C=O bond in synclinal orientation (dihedral angle tau(O=C-C-C)=49.0(3.0) degrees) and the other C=O bond in anticlinal orientation (dihedral angle tau(O=C-C-C)=139.5(3.3) degrees). The experimental geometric parameters are reproduced very closely by the B3LYP method.

摘要

已通过气体电子衍射（GED）和量子化学计算（采用6-311++G(3df,pd)基组的B3LYP和MP2近似方法）研究了丙二酰胺（NH2C(O)-CH2-C(O)NH2）的几何结构。GED和量子化学均表明，在气相中存在单一的二酮构象异构体。根据GED精修，该构象异构体具有(sc,ac)构象，其中一个C=O键呈顺错取向（二面角tau(O=C-C-C)=49.0(3.0)度），另一个C=O键呈反错取向（二面角tau(O=C-C-C)=139.5(3.3)度）。通过B3LYP方法能够非常精确地重现实验几何参数。