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Title: Electronic Structures of Tris(Dioxolene)Chromium And Tris(Dithiolene)Chromium Complexes of the Electron-Transfer Series [Cr(Dioxolene)(3)]**Z And [Cr(Diothiolene)(3)]**Z (Z = 0, 1-, 2-, 3-). a Combined Experimental And DensityFunctional Theoretical Stud

Abstract

From the reaction mixture of 3,6-di-tert-butylcatechol, H{sub 2}[{sup 3,6}L{sub cat}], [CrCl{sub 3}(thf){sub 3}], and NEt{sub 3} in CH{sub 3}CN in the presence of air, the neutral complex [Cr{sup III}({sup 3,6}L{sup {sm_bullet}}{sub sq}){sub 3}] (S = 0) (1) was isolated. Reduction of 1 with [Co(Cp){sub 2}] in CH{sub 2}Cl{sub 2} yielded microcrystals of [Co(Cp){sub 2}][Cr{sup III}({sup 3,6}L{sup {sm_bullet}}{sub sq}){sub 2}({sup 3,6}L{sub cat})] (S = {1/2}) (2) where ({sup 3,6}L{sup {sm_bullet}}{sub sq}){sup 1-} is the {pi}-radical monoanionic o-semiquinonate of the catecholate dianion ({sup 3,6}L{sub cat}){sup 2-}. Electrochemistry demonstrated that both species are members of the electron-transfer series [Cr({sup 3,6}L{sub o,o})]{sup z} (z = 0, 1-, 2-, 3-). The corresponding tris(benzo-1,2-dithiolato)chromium complex [N(n-Bu){sub 4}][Cr{sup III}({sup 3,5}L{sup {sm_bullet}}{sub s,s}){sub 2}({sup 3,5}L{sub s,s})] (S = 1/2) (3) has also been isolated; ({sup 3,5}L{sub s,s}){sup 2-} represents the closed-shell dianion 3,5-di-tert-butylbenzene-1,2-dithiolate(2-), and ({sup 3,5}L{sup {sm_bullet}}{sub s,s}){sup 1-} is its monoanionic {pi} radical. Complex 3 is a member of the electron-transfer series [Cr({sup 3,5}L{sub s,s}){sub 3}]{sup z} (z = 0, 1-, 2-, 3-). It is shown by Cr K-edge and S K-edge X-ray absorption, UV-vis, and EPR spectroscopies, as well as X-ray crystallography, of 1 and 3 that the oxidation state of the central Cr ion inmore » each member of both electron-transfer series remains the same (+III) and that all redox processes are ligand-based. These experimental results have been corroborated by broken symmetry density functional theoretical calculations by using the B3LYP functional.« less

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Stanford Linear Accelerator Center (SLAC)
Sponsoring Org.:
USDOE
OSTI Identifier:
953999
Report Number(s):
SLAC-REPRINT-2009-393
Journal ID: ISSN 0020-1669; INOCAJ; TRN: US201004%%736
DOE Contract Number:  
AC02-76SF00515
Resource Type:
Journal Article
Journal Name:
Inorg. Chem. 46:7827,2007
Additional Journal Information:
Journal Volume: 46; Journal Issue: 19; Journal ID: ISSN 0020-1669
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ABSORPTION SPECTROSCOPY; AIR; COMPLEXES; CRYSTALLOGRAPHY; DENSITY FUNCTIONAL METHOD; ELECTROCHEMISTRY; ELECTRON SPIN RESONANCE; ELECTRON TRANSFER; ELECTRONIC STRUCTURE; FUNCTIONALS; IONS; MIXTURES; REDUCTION; SYMMETRY; VALENCE; Other,OTHER, CHEM

Citation Formats

Kapre, R R, Bothe, E, Weyhermuller, T, George, S DeBeer, Muresan, N, and Wieghardt, K. Electronic Structures of Tris(Dioxolene)Chromium And Tris(Dithiolene)Chromium Complexes of the Electron-Transfer Series [Cr(Dioxolene)(3)]**Z And [Cr(Diothiolene)(3)]**Z (Z = 0, 1-, 2-, 3-). a Combined Experimental And DensityFunctional Theoretical Stud. United States: N. p., 2009. Web.
Kapre, R R, Bothe, E, Weyhermuller, T, George, S DeBeer, Muresan, N, & Wieghardt, K. Electronic Structures of Tris(Dioxolene)Chromium And Tris(Dithiolene)Chromium Complexes of the Electron-Transfer Series [Cr(Dioxolene)(3)]**Z And [Cr(Diothiolene)(3)]**Z (Z = 0, 1-, 2-, 3-). a Combined Experimental And DensityFunctional Theoretical Stud. United States.
Kapre, R R, Bothe, E, Weyhermuller, T, George, S DeBeer, Muresan, N, and Wieghardt, K. Mon . "Electronic Structures of Tris(Dioxolene)Chromium And Tris(Dithiolene)Chromium Complexes of the Electron-Transfer Series [Cr(Dioxolene)(3)]**Z And [Cr(Diothiolene)(3)]**Z (Z = 0, 1-, 2-, 3-). a Combined Experimental And DensityFunctional Theoretical Stud". United States.
@article{osti_953999,
title = {Electronic Structures of Tris(Dioxolene)Chromium And Tris(Dithiolene)Chromium Complexes of the Electron-Transfer Series [Cr(Dioxolene)(3)]**Z And [Cr(Diothiolene)(3)]**Z (Z = 0, 1-, 2-, 3-). a Combined Experimental And DensityFunctional Theoretical Stud},
author = {Kapre, R R and Bothe, E and Weyhermuller, T and George, S DeBeer and Muresan, N and Wieghardt, K},
abstractNote = {From the reaction mixture of 3,6-di-tert-butylcatechol, H{sub 2}[{sup 3,6}L{sub cat}], [CrCl{sub 3}(thf){sub 3}], and NEt{sub 3} in CH{sub 3}CN in the presence of air, the neutral complex [Cr{sup III}({sup 3,6}L{sup {sm_bullet}}{sub sq}){sub 3}] (S = 0) (1) was isolated. Reduction of 1 with [Co(Cp){sub 2}] in CH{sub 2}Cl{sub 2} yielded microcrystals of [Co(Cp){sub 2}][Cr{sup III}({sup 3,6}L{sup {sm_bullet}}{sub sq}){sub 2}({sup 3,6}L{sub cat})] (S = {1/2}) (2) where ({sup 3,6}L{sup {sm_bullet}}{sub sq}){sup 1-} is the {pi}-radical monoanionic o-semiquinonate of the catecholate dianion ({sup 3,6}L{sub cat}){sup 2-}. Electrochemistry demonstrated that both species are members of the electron-transfer series [Cr({sup 3,6}L{sub o,o})]{sup z} (z = 0, 1-, 2-, 3-). The corresponding tris(benzo-1,2-dithiolato)chromium complex [N(n-Bu){sub 4}][Cr{sup III}({sup 3,5}L{sup {sm_bullet}}{sub s,s}){sub 2}({sup 3,5}L{sub s,s})] (S = 1/2) (3) has also been isolated; ({sup 3,5}L{sub s,s}){sup 2-} represents the closed-shell dianion 3,5-di-tert-butylbenzene-1,2-dithiolate(2-), and ({sup 3,5}L{sup {sm_bullet}}{sub s,s}){sup 1-} is its monoanionic {pi} radical. Complex 3 is a member of the electron-transfer series [Cr({sup 3,5}L{sub s,s}){sub 3}]{sup z} (z = 0, 1-, 2-, 3-). It is shown by Cr K-edge and S K-edge X-ray absorption, UV-vis, and EPR spectroscopies, as well as X-ray crystallography, of 1 and 3 that the oxidation state of the central Cr ion in each member of both electron-transfer series remains the same (+III) and that all redox processes are ligand-based. These experimental results have been corroborated by broken symmetry density functional theoretical calculations by using the B3LYP functional.},
doi = {},
journal = {Inorg. Chem. 46:7827,2007},
issn = {0020-1669},
number = 19,
volume = 46,
place = {United States},
year = {2009},
month = {6}
}