CONFORMATIONAL-ANALYSIS OF SUCCINAMIDE ANALOGS

An ab initio quantum mechanical study of the conformational preferences on N,N'-dimethylsuccinamide has been performed at the HF/6-31G*, HF/6-31++G**, MP2/6-31G*, MP3/6-31G*, and MP4(SDTQ)/6-31G* computational levels. Furthermore, the effect of an aqueous environment has been simulated with a SCRF method using a 6-31G* basis set. Results show the intrinsic tendency of the central methylene units to adopt a gauche conformation. This result contrasts with the all-trans conformation expected in polymethylenic segments, although it is in good agreement with recent experimental data. Finally, the variation of the charge distribution with the conformation has been investigated and compared with that of other retroamide compounds.