NORMAL COORDINATE ANALYSIS OF DISILENES AND DIPHOSPHENES - THE UPSILON(SI=SI) AND UPSILON(P=P) STRETCHING VIBRATIONS

摘要

Normal coordinate analysis (NCA) of some disilene and diphosphene molecules has been performed and compared with NCA of corresponding alkenes. For various models of disilenes containing the C2Si=SiC2 moiety, NCA shows that Si=Si and Si-C stretching coordinates are heavily mixed, their in-phase combination resulting in a normal mode in the region 450-550 cm(-1), while their out-of-phase combination is in the region 600-750 cm(-1). In contrast, the results of NCA for diphosphenes show that the vibration at approximate to 600 cm(-1) is well localized, being predominantly nu P=P stretch ( approximate to 90% in PED). (C) 1997 Elsevier Science B.V. [References: 10]