Accession Number:

ADA252544

Title:

Exploration of the Ionizable Metal Cluster-Electrode Surface Analogy: Infrared Spectroelectrochemistry of (Pt24(CO)30)n, (Pt26(CO)32)n, and (Pt38(CO) 44)n (n=0 to -10), and Comparisons with Potential-Dependent Spectra of CO adlayers on Platinum Surfaces

Descriptive Note:

Technical rept.,

Corporate Author:

PURDUE UNIV LAFAYETTE IN DEPT OF CHEMISTRY

Report Date:

1992-05-01

Pagination or Media Count:

49.0

Abstract:

Infrared spectroelectrochemistry has been utilized to explore the vibrational properties of the high-nuclearity platinum carbonyl clusters Pt24CO30n, etc. as a function of the charge n in dichloromethane, acetonitrile, acetone, tetrahydrofuran, and methanol. The clusters exhibit unusually reversible voltammetric and spectroelectrochemical behavior, with a sequence of redox steps spanning n 0 to in one case -10, having formal potentials, Ef, between ca 0.5 and -2.5 V vs ferrocenium-ferrocene. Largely two- electron steps are observed for Pt26CO32n, involving even-charge states n -2, -4, -6, -8, -10. Sequential one-electron steps are found for Pt24CO30n and Pt38CO44n, although the regions of electrode potential over which odd- charge states n -1, -3, -5, -7 are stable i.e., the spacings between Ef values are markedly smaller than for the even-charge states. The C-O stretching frequencies for the bridging vbco and especially the terminal vtco coordinated CO ligands decrease systematically as n becomes more negative. Author

Subject Categories:

  • Organic Chemistry
  • Physical Chemistry
  • Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE