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
Abstract
Infrared spectroelectrochemistry has been utilized to explore the vibrational properties of the high-nuclearity platinum carbonyl clusters (Pt24(CO)30)n, 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 (Pt26(CO)32)n, involving even-charge states (n = -2, -4, -6, -8, -10). Sequential one-electron steps are found for (Pt24(CO)30)n and (Pt38(CO)44)n, 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 (v(b)(co)) and especially the terminal (v(t)(co)) coordinated CO ligands decrease systematically as n becomes more negative. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1992
- Accession Number
- ADA252544
Entities
People
- G. J. Lewis
- John D. Roth
- L. F. Dahl
- L. K. Safford
- Xin Jiang
Organizations
- Purdue University