Modifying electronic communication in dimolybdenum units by linkage isomers of bridged oxamidate dianions.

نویسندگان

  • F Albert Cotton
  • Chun Y Liu
  • Carlos A Murillo
  • Dino Villagrán
  • Xiaoping Wang
چکیده

Reactions of Mo(2)(O(2)CCH(3))(DAniF)(3), DAniF = N,N'-di-p-anisylformamidinate, with oxamidate dianions [ArNC(O)C(O)NAr](2-), Ar = C(6)H(5) and p-anisyl, give pairs of isomeric compounds where the [Mo(2)] units are bridged by the oxamidate anions. For the alpha isomers, the C-C unit of the dianion is nearly perpendicular to the Mo-Mo bonds, and these are essentially perpendicular to each other. For the beta isomers, the corresponding C-C unit and the Mo-Mo bonds are essentially parallel to each other. Each type of isomer is stable in solution. The electronic communication as measured by the DeltaE(1/2) for the oxidation of each of the Mo(2) units is significantly better for the beta isomers. This is supported also by the appearance of what is conventionally called an intervalence charge-transfer band in the near infrared region upon oxidation of the beta isomers but not the alpha isomers. Molecular mechanics and DFT calculations help explain the relative conformations in the alpha isomers and the relative energy differences between the alpha and beta isomers.

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عنوان ژورنال:
  • Journal of the American Chemical Society

دوره 125 44  شماره 

صفحات  -

تاریخ انتشار 2003