Molecular and electronic structure of square-planar gold complexes containing two 1,2-di(4-tert-butylphenyl)ethylene-1,2-dithiolato ligands

[Au(2L)2]1+/0/1-/2-. A combined experimental and computational study

Swarnalatha Kokatam, Kallol Ray, J. Pap, Eckhard Bill, William E. Geiger, Robert J. LeSuer, Philip H. Rieger, Thomas Weyhermüller, Frank Neese, Karl Wieghardt

Research output: Contribution to journalArticle

51 Citations (Scopus)

Abstract

From the reaction of in situ generated 1,2-di(4-tert-butylphenyl)ethylene- 1,2-dithiol, 2LH2, and Na[AuCl4]·H 2O in 1,4-dioxane, green brown crystals of diamagnetic [N(n-Bu) 4][AuIII(2L)2] (1) were obtained. As shown by cyclic voltammetry, 1 is a member of an electron-transfer series comprising the dianion [AuII(2L)2] 2-, the monoanion [AuIII(2L)2] -, the neutral species [AuIII(2L )(2L)]0 ↔ [AuIII( 2L)(2L)]0, and the monocation [AuIII(2L)2]+. (2L)1- represents the π radical anion (Srad = 1/2) of the one-electron oxidized closed-shell dianion ( 2L)2-. Oxidation of 1 in CH2Cl2 with ferrocenium hexafluorophosphate affords green, paramagnetic microcrystals of [AuIII(2L)(2L)] ↔ [AuIII(2L)(2L)] (2) (S = 1/2). Complexes 1 and 2 have been characterized by X-ray crystallography. Both species possess square-planar monoanions and neutral molecules, respectively. From the oxidation reaction of 1 or [N(n-Bu)4][AuIII( 3L)2] with 2-3 equiv of [NO]BF4 in CH 2Cl2, a green solution of [AuIII( 2L)2]+ and green microcrystals of [AuIII(3L)2]BF4 (3) were obtained, respectively; (3L)2- represents the dianion 1,2-di(4-diphenyl)ethylene-1,2-dithiolate, and (3L )1- is its π radical monoanion. The electronic structures of this series of gold species have been elucidated by UV-vis, EPR spectroscopies, and DFT calculations. It is shown computationally by density functional theoretical (DFT) methods that the electronic structure of [Au III(1L)2]+ is best described as a singlet diradical (St = 0); the ligand mixed valency in the neutral species 2 is of class (III) (delocalized); the monoanion in 1 contains a AuIII ion and two closed-shell dianionic ligands; and the corresponding dianions [Au(L)2]2- are best described as an intermediate AuII/AuIII species with a metal-ligand delocalized SOMO (25% Au 5d, 75% 3p of four S atoms). (1L) 2- is the dianion 1,2-di(phenyl)ethylene-1,2-dithiolate, and ( 1L)1- is the π radical monoanion. The neutral species [PdII(2L)2] (4) has also been synthesized and characterized by X-ray crystallography. Its electronic structure is the same as described for [AuIII( 1L)2]+ (singlet diradical), whereas that of the monoanion [PdII(2L) (2L)]- ↔ [Pd(2L)(2L )]- corresponds to that of the neutral gold complex 2. Anodic oxidation of the analogous monoanion [AuIII(mnt) 2]-, where mnt = maleonitriledithiolate, gave the neutral complex [Au(mnt)(mnt)] (E1/2 = 0.91 V vs Fc +/Fc). The optical and EPR spectroscopies of [Au(mnt)(mnt )] were consistent with those observed for the corresponding di(tert-butylphenyl)-ethylenedithiolate complex 2.

Original languageEnglish
Pages (from-to)1100-1111
Number of pages12
JournalInorganic Chemistry
Volume46
Issue number4
DOIs
Publication statusPublished - Feb 19 2007

Fingerprint

Gold
Molecular structure
Electronic structure
Microcrystals
ethylene
molecular structure
X ray crystallography
microcrystals
gold
electronic structure
Ligands
ligands
oxidation
crystallography
Paramagnetic resonance
Spectroscopy
Oxidation
Electrons
Anodic oxidation
thiols

ASJC Scopus subject areas

  • Inorganic Chemistry

Cite this

Molecular and electronic structure of square-planar gold complexes containing two 1,2-di(4-tert-butylphenyl)ethylene-1,2-dithiolato ligands : [Au(2L)2]1+/0/1-/2-. A combined experimental and computational study. / Kokatam, Swarnalatha; Ray, Kallol; Pap, J.; Bill, Eckhard; Geiger, William E.; LeSuer, Robert J.; Rieger, Philip H.; Weyhermüller, Thomas; Neese, Frank; Wieghardt, Karl.

In: Inorganic Chemistry, Vol. 46, No. 4, 19.02.2007, p. 1100-1111.

Research output: Contribution to journalArticle

Kokatam, Swarnalatha ; Ray, Kallol ; Pap, J. ; Bill, Eckhard ; Geiger, William E. ; LeSuer, Robert J. ; Rieger, Philip H. ; Weyhermüller, Thomas ; Neese, Frank ; Wieghardt, Karl. / Molecular and electronic structure of square-planar gold complexes containing two 1,2-di(4-tert-butylphenyl)ethylene-1,2-dithiolato ligands : [Au(2L)2]1+/0/1-/2-. A combined experimental and computational study. In: Inorganic Chemistry. 2007 ; Vol. 46, No. 4. pp. 1100-1111.
@article{a65f471485b44c309b53b7b3efb92849,
title = "Molecular and electronic structure of square-planar gold complexes containing two 1,2-di(4-tert-butylphenyl)ethylene-1,2-dithiolato ligands: [Au(2L)2]1+/0/1-/2-. A combined experimental and computational study",
abstract = "From the reaction of in situ generated 1,2-di(4-tert-butylphenyl)ethylene- 1,2-dithiol, 2LH2, and Na[AuCl4]·H 2O in 1,4-dioxane, green brown crystals of diamagnetic [N(n-Bu) 4][AuIII(2L)2] (1) were obtained. As shown by cyclic voltammetry, 1 is a member of an electron-transfer series comprising the dianion [AuII(2L)2] 2-, the monoanion [AuIII(2L)2] -, the neutral species [AuIII(2L •)(2L)]0 ↔ [AuIII( 2L)(2L•)]0, and the monocation [AuIII(2L•)2]+. (2L•)1- represents the π radical anion (Srad = 1/2) of the one-electron oxidized closed-shell dianion ( 2L)2-. Oxidation of 1 in CH2Cl2 with ferrocenium hexafluorophosphate affords green, paramagnetic microcrystals of [AuIII(2L•)(2L)] ↔ [AuIII(2L)(2L•)] (2) (S = 1/2). Complexes 1 and 2 have been characterized by X-ray crystallography. Both species possess square-planar monoanions and neutral molecules, respectively. From the oxidation reaction of 1 or [N(n-Bu)4][AuIII( 3L)2] with 2-3 equiv of [NO]BF4 in CH 2Cl2, a green solution of [AuIII( 2L•)2]+ and green microcrystals of [AuIII(3L•)2]BF4 (3) were obtained, respectively; (3L)2- represents the dianion 1,2-di(4-diphenyl)ethylene-1,2-dithiolate, and (3L •)1- is its π radical monoanion. The electronic structures of this series of gold species have been elucidated by UV-vis, EPR spectroscopies, and DFT calculations. It is shown computationally by density functional theoretical (DFT) methods that the electronic structure of [Au III(1L•)2]+ is best described as a singlet diradical (St = 0); the ligand mixed valency in the neutral species 2 is of class (III) (delocalized); the monoanion in 1 contains a AuIII ion and two closed-shell dianionic ligands; and the corresponding dianions [Au(L)2]2- are best described as an intermediate AuII/AuIII species with a metal-ligand delocalized SOMO (25{\%} Au 5d, 75{\%} 3p of four S atoms). (1L) 2- is the dianion 1,2-di(phenyl)ethylene-1,2-dithiolate, and ( 1L•)1- is the π radical monoanion. The neutral species [PdII(2L•)2] (4) has also been synthesized and characterized by X-ray crystallography. Its electronic structure is the same as described for [AuIII( 1L•)2]+ (singlet diradical), whereas that of the monoanion [PdII(2L•) (2L)]- ↔ [Pd(2L)(2L •)]- corresponds to that of the neutral gold complex 2. Anodic oxidation of the analogous monoanion [AuIII(mnt) 2]-, where mnt = maleonitriledithiolate, gave the neutral complex [Au(mnt)(mnt•)] (E1/2 = 0.91 V vs Fc +/Fc). The optical and EPR spectroscopies of [Au(mnt)(mnt •)] were consistent with those observed for the corresponding di(tert-butylphenyl)-ethylenedithiolate complex 2.",
author = "Swarnalatha Kokatam and Kallol Ray and J. Pap and Eckhard Bill and Geiger, {William E.} and LeSuer, {Robert J.} and Rieger, {Philip H.} and Thomas Weyherm{\"u}ller and Frank Neese and Karl Wieghardt",
year = "2007",
month = "2",
day = "19",
doi = "10.1021/ic061181u",
language = "English",
volume = "46",
pages = "1100--1111",
journal = "Inorganic Chemistry",
issn = "0020-1669",
publisher = "American Chemical Society",
number = "4",

}

TY - JOUR

T1 - Molecular and electronic structure of square-planar gold complexes containing two 1,2-di(4-tert-butylphenyl)ethylene-1,2-dithiolato ligands

T2 - [Au(2L)2]1+/0/1-/2-. A combined experimental and computational study

AU - Kokatam, Swarnalatha

AU - Ray, Kallol

AU - Pap, J.

AU - Bill, Eckhard

AU - Geiger, William E.

AU - LeSuer, Robert J.

AU - Rieger, Philip H.

AU - Weyhermüller, Thomas

AU - Neese, Frank

AU - Wieghardt, Karl

PY - 2007/2/19

Y1 - 2007/2/19

N2 - From the reaction of in situ generated 1,2-di(4-tert-butylphenyl)ethylene- 1,2-dithiol, 2LH2, and Na[AuCl4]·H 2O in 1,4-dioxane, green brown crystals of diamagnetic [N(n-Bu) 4][AuIII(2L)2] (1) were obtained. As shown by cyclic voltammetry, 1 is a member of an electron-transfer series comprising the dianion [AuII(2L)2] 2-, the monoanion [AuIII(2L)2] -, the neutral species [AuIII(2L •)(2L)]0 ↔ [AuIII( 2L)(2L•)]0, and the monocation [AuIII(2L•)2]+. (2L•)1- represents the π radical anion (Srad = 1/2) of the one-electron oxidized closed-shell dianion ( 2L)2-. Oxidation of 1 in CH2Cl2 with ferrocenium hexafluorophosphate affords green, paramagnetic microcrystals of [AuIII(2L•)(2L)] ↔ [AuIII(2L)(2L•)] (2) (S = 1/2). Complexes 1 and 2 have been characterized by X-ray crystallography. Both species possess square-planar monoanions and neutral molecules, respectively. From the oxidation reaction of 1 or [N(n-Bu)4][AuIII( 3L)2] with 2-3 equiv of [NO]BF4 in CH 2Cl2, a green solution of [AuIII( 2L•)2]+ and green microcrystals of [AuIII(3L•)2]BF4 (3) were obtained, respectively; (3L)2- represents the dianion 1,2-di(4-diphenyl)ethylene-1,2-dithiolate, and (3L •)1- is its π radical monoanion. The electronic structures of this series of gold species have been elucidated by UV-vis, EPR spectroscopies, and DFT calculations. It is shown computationally by density functional theoretical (DFT) methods that the electronic structure of [Au III(1L•)2]+ is best described as a singlet diradical (St = 0); the ligand mixed valency in the neutral species 2 is of class (III) (delocalized); the monoanion in 1 contains a AuIII ion and two closed-shell dianionic ligands; and the corresponding dianions [Au(L)2]2- are best described as an intermediate AuII/AuIII species with a metal-ligand delocalized SOMO (25% Au 5d, 75% 3p of four S atoms). (1L) 2- is the dianion 1,2-di(phenyl)ethylene-1,2-dithiolate, and ( 1L•)1- is the π radical monoanion. The neutral species [PdII(2L•)2] (4) has also been synthesized and characterized by X-ray crystallography. Its electronic structure is the same as described for [AuIII( 1L•)2]+ (singlet diradical), whereas that of the monoanion [PdII(2L•) (2L)]- ↔ [Pd(2L)(2L •)]- corresponds to that of the neutral gold complex 2. Anodic oxidation of the analogous monoanion [AuIII(mnt) 2]-, where mnt = maleonitriledithiolate, gave the neutral complex [Au(mnt)(mnt•)] (E1/2 = 0.91 V vs Fc +/Fc). The optical and EPR spectroscopies of [Au(mnt)(mnt •)] were consistent with those observed for the corresponding di(tert-butylphenyl)-ethylenedithiolate complex 2.

AB - From the reaction of in situ generated 1,2-di(4-tert-butylphenyl)ethylene- 1,2-dithiol, 2LH2, and Na[AuCl4]·H 2O in 1,4-dioxane, green brown crystals of diamagnetic [N(n-Bu) 4][AuIII(2L)2] (1) were obtained. As shown by cyclic voltammetry, 1 is a member of an electron-transfer series comprising the dianion [AuII(2L)2] 2-, the monoanion [AuIII(2L)2] -, the neutral species [AuIII(2L •)(2L)]0 ↔ [AuIII( 2L)(2L•)]0, and the monocation [AuIII(2L•)2]+. (2L•)1- represents the π radical anion (Srad = 1/2) of the one-electron oxidized closed-shell dianion ( 2L)2-. Oxidation of 1 in CH2Cl2 with ferrocenium hexafluorophosphate affords green, paramagnetic microcrystals of [AuIII(2L•)(2L)] ↔ [AuIII(2L)(2L•)] (2) (S = 1/2). Complexes 1 and 2 have been characterized by X-ray crystallography. Both species possess square-planar monoanions and neutral molecules, respectively. From the oxidation reaction of 1 or [N(n-Bu)4][AuIII( 3L)2] with 2-3 equiv of [NO]BF4 in CH 2Cl2, a green solution of [AuIII( 2L•)2]+ and green microcrystals of [AuIII(3L•)2]BF4 (3) were obtained, respectively; (3L)2- represents the dianion 1,2-di(4-diphenyl)ethylene-1,2-dithiolate, and (3L •)1- is its π radical monoanion. The electronic structures of this series of gold species have been elucidated by UV-vis, EPR spectroscopies, and DFT calculations. It is shown computationally by density functional theoretical (DFT) methods that the electronic structure of [Au III(1L•)2]+ is best described as a singlet diradical (St = 0); the ligand mixed valency in the neutral species 2 is of class (III) (delocalized); the monoanion in 1 contains a AuIII ion and two closed-shell dianionic ligands; and the corresponding dianions [Au(L)2]2- are best described as an intermediate AuII/AuIII species with a metal-ligand delocalized SOMO (25% Au 5d, 75% 3p of four S atoms). (1L) 2- is the dianion 1,2-di(phenyl)ethylene-1,2-dithiolate, and ( 1L•)1- is the π radical monoanion. The neutral species [PdII(2L•)2] (4) has also been synthesized and characterized by X-ray crystallography. Its electronic structure is the same as described for [AuIII( 1L•)2]+ (singlet diradical), whereas that of the monoanion [PdII(2L•) (2L)]- ↔ [Pd(2L)(2L •)]- corresponds to that of the neutral gold complex 2. Anodic oxidation of the analogous monoanion [AuIII(mnt) 2]-, where mnt = maleonitriledithiolate, gave the neutral complex [Au(mnt)(mnt•)] (E1/2 = 0.91 V vs Fc +/Fc). The optical and EPR spectroscopies of [Au(mnt)(mnt •)] were consistent with those observed for the corresponding di(tert-butylphenyl)-ethylenedithiolate complex 2.

UR - http://www.scopus.com/inward/record.url?scp=33847710343&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33847710343&partnerID=8YFLogxK

U2 - 10.1021/ic061181u

DO - 10.1021/ic061181u

M3 - Article

VL - 46

SP - 1100

EP - 1111

JO - Inorganic Chemistry

JF - Inorganic Chemistry

SN - 0020-1669

IS - 4

ER -