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Electronic Structure of Complexes of the Ligand o-Phenylenebisdimethylarsine


Bernstein, Paula K. (1971) Electronic Structure of Complexes of the Ligand o-Phenylenebisdimethylarsine. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/xyq9-hp49.


Various studies have been carried out to elucidate the detailed electronic structure of the unusual spin doublet complex [Ni(diars)2X2]Y (X = Cl, Br, -NCS; Y = CL, Br, -NCS, ClO4-). An X-ray crystallographic study has been done which confirmed its coordination number of six. U.v. and visible spectra have been taken of it and of other closely related cobalt and nickel complexes. Assignments for the charge transfer and ligand field spectra are suggested. ESR studies have been done in solution, powder, and single crystal to extract the components of the ligand superhyperfine splitting tensors. A semi-quantitative MO scheme, consistent with these tensor values, has been used to explain some of the unusual properties of this complex.

We have concluded from these studies that the energy level ordering in Ni(diarsine)2X2+ is x2 - y- < xz, yz < z2 < xy and that the ground state is 2Ag. The ground state is highly delocalized, consisting of approximately 50% ligand character distributed over all six ligands. The tipping of the benzene rings and the distortion of the axial ligands permits an admixture of chlorine px orbitals into the ground state molecular orbital which serves to further stabilize this system.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Chemistry
Degree Grantor:California Institute of Technology
Division:Chemistry and Chemical Engineering
Major Option:Chemistry
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Gray, Harry B. (advisor)
  • Marsh, Richard Edward (co-advisor)
Thesis Committee:
  • Unknown, Unknown
Defense Date:23 September 1970
Funding AgencyGrant Number
National Defense Education ActUNSPECIFIED
Record Number:CaltechTHESIS:12062017-085349488
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:10588
Deposited By: Benjamin Perez
Deposited On:06 Dec 2017 17:55
Last Modified:16 Apr 2021 23:22

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