Disproportionation of Gold(II) Complexes. A Density Functional Study of Ligand and Solvent Effects

Description:

This article discusses disproportionation of gold(II) as an atomic ion as well as with chloride and neutral ligands.

Creator(s):
Creation Date: July 13, 2006
Partner(s):
UNT College of Arts and Sciences
Collection(s):
UNT Scholarly Works
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Total Uses: 281
Past 30 days: 12
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Creator (Author):
Barakat, Khaldoon A.

University of North Texas

Creator (Author):
Cundari, Thomas R., 1964-

University of North Texas

Creator (Author):
Rabaâ, Hassan

University of North Texas; Ibn Tofail University

Creator (Author):
Omary, Mohammad A.

University of North Texas

Publisher Info:
Publisher Name: American Chemical Society
Place of Publication: [Washington, DC]
Date(s):
  • Creation: July 13, 2006
Description:

This article discusses disproportionation of gold(II) as an atomic ion as well as with chloride and neutral ligands.

Degree:
Department: Chemistry
Note:

Reprinted with permission from the Journal of Physical Chemistry B. Copyright 2006 American Chemical Society.

Note:

Abstract: A computational study of gold(II) disproportionation is presented for the atomic ion as well as complexes with chloride and neutral ligands. The Au²⁺ atomic ion is stable to disproportionation, but the barrier is more than halved to 119 kcal/mol in an aqueous environment vs 283 kcal/mol in the gas phase. For dissociative disproportionation of chloride complexes, the loss of chlorine, either as an atom (∆Gaq = +20 kcal/mol) or as an anion (∆Gaq = +15 kcal/mol) represents the largest calculated barrier. The calculated transition state for associative disproportionation is only 9 kcal/mol above separated Auᴵᴵ complex, a nonpolar solvent is preferred. With the exception of [Au(CO₃]²⁺, disproportionation of AuᴵᴵL₃ complexes to AuᴵL and AuᴵᴵᴵL₃ is exergonic in solution phase for the ligands investigated. The driving force is provided by the very favorable solvation free energy of the trivalent gold complex. The solvation free energy contribution to the reaction (∆Gsolv) is very large for small and polar ligands such as ammonia and water. Furthermore, calculations imply that choosing ligands that would yield neutral species upon disproportionation may provide an effective route to thwart this decomposition pathway for Auᴵᴵ complexes. Likewise, bulkier ligands that yield larger, more weakly solvated complex ions would appear to be desirable.

Physical Description:

7 p.

Language(s):
Subject(s):
Keyword(s): gold(II) complexes | ligands | solvent effects
Source: Journal of Physical Chemistry B, 2006, Washington DC: American Chemical Society, pp. 14645-14651
Partner:
UNT College of Arts and Sciences
Collection:
UNT Scholarly Works
Identifier:
  • DOI: 10.1021/jp062501y
  • ARK: ark:/67531/metadc77172
Resource Type: Article
Format: Text
Rights:
Access: Public
Citation:
Publication Title: Journal of Physical Chemistry B
Volume: 110
Page Start: 14645
Page End: 14651
Pages: 7
Peer Reviewed: Yes