Publication Date

1981

Document Type

Dissertation/Thesis

First Advisor

Mason, W. Roy

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Chemistry

LCSH

Dichroism; Metal ions; Ligands; Transition metal compounds--Magnetic properties

Abstract

Electronic absorption and magnetic circular dichroisn (MCD) spectral measurements are reported for the octahedral nd⁶ carbonyl and cyano complexes M(CO)₆ (M = Cr, Mo, W) and K₄[M(CN)₆] (M = Fe, Ru, Os), the linear nd¹⁰ complexes [M(CNC₂H₅)₂]ClO₄ (M = Ag, Au, Hg), [Au(P(OR)₃)₂]ClO₄ (R = CH₃, C₂H₅), [Au(CNCH₃)CN], and the tetrahedral 3d¹⁰ complexes K₃[Cu(CN)₄], and [Cu(CNC₂H₅)₄]ClO₄. The intense absorptions observed for the M(CO)₆ and [M(CN)₆]⁴⁻ complexes are characterized as metal to ligand charge transfer (MLCT) from the occupied metal d orbitals to the empty π* ligand orbitals (t[sub 2g] → t[sub lu]* and t[sub 2u]*). The spectral pattern observed in the MCD for the two lowest allowed bands of the M(CO)₆ is similar and consists of a positive B̲ term for the band near 3.5 μm⁻¹ and a negative B̲ term for the band near 4.4 μm⁻¹. The difference between the MCD for the lowest energy MLCT between M(CO)₆ and [M(CN)₆]⁴⁻ complexes is discussed in terms of relative p orbital participation in the empty t[sub lu]* ligand orbital. The rich absorption and MCD spectra for [Au(CNC₂H₅)₂]C1O₄ are interpreted in terms of MLCT excitations (d(σ⁺[sub g], δ [sub g], π[sub g]) → π*). A detailed interpretation of [Au(CNC₂H₅)₂]C1O₄ spectra is given based on an energy level scheme which includes spin-orbit coupling. Spectral assignments for [Au(CNC₂H₅)₂]⁺ are compared to the similar absorption bands in the [Au(CN)₂]⁻, [Au(P(OR)₃)₂]⁺, and [Au(CNCH₃)CN] complexes. The results are also discussed in terms of d orbital participation in bonding with these π- acceptor ligands. The spectra for K₃[Cu(CN)₄] consists of two major absorption bands at 4.21 and 4.85 μm⁻¹. The MCD for these bands show two distinct positive A̲ terms for both absorption bands. These bands are assigned to a MLCT and ligand to ligand (π → π*) excitation, respectively. A comparison of these assignments with the spectra of [Cu(CNC₂H₅)₄]ClO₄ is also presented.

Comments

Includes bibliographical references.||Includes illustrations.

Extent

vi, 85 pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

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