Charge Distribution Dependent on the Chelating Ratio. [Co(μ-bpym)(dbbq)2] vs. [{Co(dbbq)2}2(μ-bpym)] (bpym=2,2′-bipyrimidine; dbbq=3,6-di-t-butyl-1,2-benzoquinone)

Ok Sang Jung; Du Hwan Jo; Young A. Lee; Hee Kwon Chae; Youn Soo Sohn

doi:10.1246/bcsj.69.2211

Charge Distribution Dependent on the Chelating Ratio. [Co(μ-bpym)(dbbq)₂] vs. [{Co(dbbq)₂}₂(μ-bpym)] (bpym=2,2′-bipyrimidine; dbbq=3,6-di-t-butyl-1,2-benzoquinone)

Ok Sang Jung^*
, Du Hwan Jo
, Young A. Lee
, Hee Kwon Chae
, Youn Soo Sohn

^*Corresponding author for this work

Department of Chemistry

Korea Institute of Science and Technology
Hankuk University of Foreign Studies

Research output: Contribution to journal › Journal article › peer-review

18 Scopus citations

Abstract

The preparation and characterization of [Co(μ-bpym)(dbbq)₂] and [{Co(dbbq)₂}₂(μ-bpym)] (bpym = 2,2′-bipyrimidine; dbbq = 3,6-di-t-butyl-1,2-benzoquinone) have been established. The temperature-dependent magnetic moments (100-400 K) and variable-temperature near-infrared (NIR) absorption spectra are presented to show that the title complexes exhibit an equilibrium via a catechol to a cobalt intramolecular electron transfer. At temperatures below 200 K the mononuclear complex [Co(μ-bpym)(dbbq)₂] has a charge distribution of [Co^III(μ-bpym)(dbcat)(dbsq)] (dbsq = 3,6-di-t-butyl-1,2-semiquinonato; dbcat=3,6-di-t-butylcatecholato), whereas at temperatures beyond 290 K the mononuclear complex is predominantly in the [Co^II(μ-bpym)(dbsq)₂] form. From 200-290 K a mixture of Co(III) and Co(II) redox isomers exists at equilibrium in the solid state. In particular, a thermal analysis of a solid sample of the mononuclear complex discloses that the transition for the Co(III)/Co(II) is accompanied by a change in the heat content of 36 kJ mol^-1, which may be closely related to the band at 3878 cm^-1, assigned as a dbcat to Co(III) charge transfer. In striking contrast, the dinuclear complex [{Co(dbbq)₂}₂(μ-bpym)] is locked in a charge distribution of [{Co^II(dbsq)₂}₂(μ-bpym)] when the temperature is 100-400 K.

Original language	English
Pages (from-to)	2211-2214
Number of pages	4
Journal	Bulletin of the Chemical Society of Japan
Volume	69
Issue number	8
DOIs	https://doi.org/10.1246/bcsj.69.2211
State	Published - 1996.08

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@article{6f028268a2034141ad024dfa87aca081,

title = "Charge Distribution Dependent on the Chelating Ratio. [Co(μ-bpym)(dbbq)2] vs. [\{Co(dbbq)2\}2(μ-bpym)] (bpym=2,2′-bipyrimidine; dbbq=3,6-di-t-butyl-1,2-benzoquinone)",

abstract = "The preparation and characterization of [Co(μ-bpym)(dbbq)2] and [\{Co(dbbq)2\}2(μ-bpym)] (bpym = 2,2′-bipyrimidine; dbbq = 3,6-di-t-butyl-1,2-benzoquinone) have been established. The temperature-dependent magnetic moments (100-400 K) and variable-temperature near-infrared (NIR) absorption spectra are presented to show that the title complexes exhibit an equilibrium via a catechol to a cobalt intramolecular electron transfer. At temperatures below 200 K the mononuclear complex [Co(μ-bpym)(dbbq)2] has a charge distribution of [CoIII(μ-bpym)(dbcat)(dbsq)] (dbsq = 3,6-di-t-butyl-1,2-semiquinonato; dbcat=3,6-di-t-butylcatecholato), whereas at temperatures beyond 290 K the mononuclear complex is predominantly in the [CoII(μ-bpym)(dbsq)2] form. From 200-290 K a mixture of Co(III) and Co(II) redox isomers exists at equilibrium in the solid state. In particular, a thermal analysis of a solid sample of the mononuclear complex discloses that the transition for the Co(III)/Co(II) is accompanied by a change in the heat content of 36 kJ mol-1, which may be closely related to the band at 3878 cm-1, assigned as a dbcat to Co(III) charge transfer. In striking contrast, the dinuclear complex [\{Co(dbbq)2\}2(μ-bpym)] is locked in a charge distribution of [\{CoII(dbsq)2\}2(μ-bpym)] when the temperature is 100-400 K.",

author = "Jung, \{Ok Sang\} and Jo, \{Du Hwan\} and Lee, \{Young A.\} and Chae, \{Hee Kwon\} and Sohn, \{Youn Soo\}",

year = "1996",

month = aug,

doi = "10.1246/bcsj.69.2211",

language = "English",

volume = "69",

pages = "2211--2214",

journal = "Bulletin of the Chemical Society of Japan",

issn = "0009-2673",

number = "8",

}

Charge Distribution Dependent on the Chelating Ratio. [Co(μ-bpym)(dbbq)₂] vs. [{Co(dbbq)₂}₂(μ-bpym)] (bpym=2,2′-bipyrimidine; dbbq=3,6-di-t-butyl-1,2-benzoquinone). / Jung, Ok Sang; Jo, Du Hwan; Lee, Young A. et al.
In: Bulletin of the Chemical Society of Japan, Vol. 69, No. 8, 08.1996, p. 2211-2214.

Research output: Contribution to journal › Journal article › peer-review

TY - JOUR

T1 - Charge Distribution Dependent on the Chelating Ratio. [Co(μ-bpym)(dbbq)2] vs. [{Co(dbbq)2}2(μ-bpym)] (bpym=2,2′-bipyrimidine; dbbq=3,6-di-t-butyl-1,2-benzoquinone)

AU - Jung, Ok Sang

AU - Jo, Du Hwan

AU - Lee, Young A.

AU - Chae, Hee Kwon

AU - Sohn, Youn Soo

PY - 1996/8

Y1 - 1996/8

N2 - The preparation and characterization of [Co(μ-bpym)(dbbq)2] and [{Co(dbbq)2}2(μ-bpym)] (bpym = 2,2′-bipyrimidine; dbbq = 3,6-di-t-butyl-1,2-benzoquinone) have been established. The temperature-dependent magnetic moments (100-400 K) and variable-temperature near-infrared (NIR) absorption spectra are presented to show that the title complexes exhibit an equilibrium via a catechol to a cobalt intramolecular electron transfer. At temperatures below 200 K the mononuclear complex [Co(μ-bpym)(dbbq)2] has a charge distribution of [CoIII(μ-bpym)(dbcat)(dbsq)] (dbsq = 3,6-di-t-butyl-1,2-semiquinonato; dbcat=3,6-di-t-butylcatecholato), whereas at temperatures beyond 290 K the mononuclear complex is predominantly in the [CoII(μ-bpym)(dbsq)2] form. From 200-290 K a mixture of Co(III) and Co(II) redox isomers exists at equilibrium in the solid state. In particular, a thermal analysis of a solid sample of the mononuclear complex discloses that the transition for the Co(III)/Co(II) is accompanied by a change in the heat content of 36 kJ mol-1, which may be closely related to the band at 3878 cm-1, assigned as a dbcat to Co(III) charge transfer. In striking contrast, the dinuclear complex [{Co(dbbq)2}2(μ-bpym)] is locked in a charge distribution of [{CoII(dbsq)2}2(μ-bpym)] when the temperature is 100-400 K.

AB - The preparation and characterization of [Co(μ-bpym)(dbbq)2] and [{Co(dbbq)2}2(μ-bpym)] (bpym = 2,2′-bipyrimidine; dbbq = 3,6-di-t-butyl-1,2-benzoquinone) have been established. The temperature-dependent magnetic moments (100-400 K) and variable-temperature near-infrared (NIR) absorption spectra are presented to show that the title complexes exhibit an equilibrium via a catechol to a cobalt intramolecular electron transfer. At temperatures below 200 K the mononuclear complex [Co(μ-bpym)(dbbq)2] has a charge distribution of [CoIII(μ-bpym)(dbcat)(dbsq)] (dbsq = 3,6-di-t-butyl-1,2-semiquinonato; dbcat=3,6-di-t-butylcatecholato), whereas at temperatures beyond 290 K the mononuclear complex is predominantly in the [CoII(μ-bpym)(dbsq)2] form. From 200-290 K a mixture of Co(III) and Co(II) redox isomers exists at equilibrium in the solid state. In particular, a thermal analysis of a solid sample of the mononuclear complex discloses that the transition for the Co(III)/Co(II) is accompanied by a change in the heat content of 36 kJ mol-1, which may be closely related to the band at 3878 cm-1, assigned as a dbcat to Co(III) charge transfer. In striking contrast, the dinuclear complex [{Co(dbbq)2}2(μ-bpym)] is locked in a charge distribution of [{CoII(dbsq)2}2(μ-bpym)] when the temperature is 100-400 K.

UR - https://www.scopus.com/pages/publications/0001295642

U2 - 10.1246/bcsj.69.2211

DO - 10.1246/bcsj.69.2211

M3 - Journal article

AN - SCOPUS:0001295642

SN - 0009-2673

VL - 69

SP - 2211

EP - 2214

JO - Bulletin of the Chemical Society of Japan

JF - Bulletin of the Chemical Society of Japan

IS - 8

ER -

Charge Distribution Dependent on the Chelating Ratio. [Co(μ-bpym)(dbbq)₂] vs. [{Co(dbbq)₂}₂(μ-bpym)] (bpym=2,2′-bipyrimidine; dbbq=3,6-di-t-butyl-1,2-benzoquinone)

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