Calorimetric study of the Lewis acid properties of coordinatively unsaturated organoiridium(III) species

T. W. Leung, M. J. Hintz, L. T. Chan, A. D. Sherry, D. M. Blake

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

The Lewis acid character of a series of coordinatively unsaturated iridium(III) complexes of the type {IrCl2R[P(C6H5)3]2} (R is C(O)CFnH3-n (n = 1, 2, or 3), -S(O)2R′ (R′ = CH3, C2H5, or CF3), or CH3) has been studied by calorimetric and spectroscopic methods. Enthalpy data for addition of pyridine as a function of R are interpreted in terms of a trans influence series for the R groups. This thermochemical trans influence series is compared with that derived from the trends in iridium-chlorine stretching frequencies in model compounds having R trans to Cl. The enthalpy change and equilibrium constant for pyridine addition to the complex in which R = C(O)CF3 were determined in six solvents. The trends in enthalpy changes and equilibrium constants for addition of a series of ten bases to the trifluoroacetyl complex in methylene chloride are interpreted in terms of base strength and steric factors. The enthalpy change for pyridine addition to {IrClXCH3[P(C6H5)3]2} (X = Cl, Br, -NCO, NO2, or CH3CO2) in methylene chloride reveals that the cis influence of X is low. Representative examples of the octahedral adducts {IrCl2R[P(C6H5)3] 2·B} have been isolated and characterized. In each case the base B is found to add stereospecifically trans to the substituent R.

Original languageEnglish (US)
Pages (from-to)2606-2612
Number of pages7
JournalInorganic Chemistry
Volume16
Issue number10
StatePublished - 1977

Fingerprint

Iridium
Lewis Acids
iridium
Enthalpy
enthalpy
pyridines
acids
Methylene Chloride
Equilibrium constants
methylene
chlorides
trends
Chlorine
adducts
Stretching
chlorine
pyridine

ASJC Scopus subject areas

  • Inorganic Chemistry

Cite this

Calorimetric study of the Lewis acid properties of coordinatively unsaturated organoiridium(III) species. / Leung, T. W.; Hintz, M. J.; Chan, L. T.; Sherry, A. D.; Blake, D. M.

In: Inorganic Chemistry, Vol. 16, No. 10, 1977, p. 2606-2612.

Research output: Contribution to journalArticle

Leung, T. W. ; Hintz, M. J. ; Chan, L. T. ; Sherry, A. D. ; Blake, D. M. / Calorimetric study of the Lewis acid properties of coordinatively unsaturated organoiridium(III) species. In: Inorganic Chemistry. 1977 ; Vol. 16, No. 10. pp. 2606-2612.
@article{e857462b14414661a5917bd7eb85c53f,
title = "Calorimetric study of the Lewis acid properties of coordinatively unsaturated organoiridium(III) species",
abstract = "The Lewis acid character of a series of coordinatively unsaturated iridium(III) complexes of the type {IrCl2R[P(C6H5)3]2} (R is C(O)CFnH3-n (n = 1, 2, or 3), -S(O)2R′ (R′ = CH3, C2H5, or CF3), or CH3) has been studied by calorimetric and spectroscopic methods. Enthalpy data for addition of pyridine as a function of R are interpreted in terms of a trans influence series for the R groups. This thermochemical trans influence series is compared with that derived from the trends in iridium-chlorine stretching frequencies in model compounds having R trans to Cl. The enthalpy change and equilibrium constant for pyridine addition to the complex in which R = C(O)CF3 were determined in six solvents. The trends in enthalpy changes and equilibrium constants for addition of a series of ten bases to the trifluoroacetyl complex in methylene chloride are interpreted in terms of base strength and steric factors. The enthalpy change for pyridine addition to {IrClXCH3[P(C6H5)3]2} (X = Cl, Br, -NCO, NO2, or CH3CO2) in methylene chloride reveals that the cis influence of X is low. Representative examples of the octahedral adducts {IrCl2R[P(C6H5)3] 2·B} have been isolated and characterized. In each case the base B is found to add stereospecifically trans to the substituent R.",
author = "Leung, {T. W.} and Hintz, {M. J.} and Chan, {L. T.} and Sherry, {A. D.} and Blake, {D. M.}",
year = "1977",
language = "English (US)",
volume = "16",
pages = "2606--2612",
journal = "Inorganic Chemistry",
issn = "0020-1669",
publisher = "American Chemical Society",
number = "10",

}

TY - JOUR

T1 - Calorimetric study of the Lewis acid properties of coordinatively unsaturated organoiridium(III) species

AU - Leung, T. W.

AU - Hintz, M. J.

AU - Chan, L. T.

AU - Sherry, A. D.

AU - Blake, D. M.

PY - 1977

Y1 - 1977

N2 - The Lewis acid character of a series of coordinatively unsaturated iridium(III) complexes of the type {IrCl2R[P(C6H5)3]2} (R is C(O)CFnH3-n (n = 1, 2, or 3), -S(O)2R′ (R′ = CH3, C2H5, or CF3), or CH3) has been studied by calorimetric and spectroscopic methods. Enthalpy data for addition of pyridine as a function of R are interpreted in terms of a trans influence series for the R groups. This thermochemical trans influence series is compared with that derived from the trends in iridium-chlorine stretching frequencies in model compounds having R trans to Cl. The enthalpy change and equilibrium constant for pyridine addition to the complex in which R = C(O)CF3 were determined in six solvents. The trends in enthalpy changes and equilibrium constants for addition of a series of ten bases to the trifluoroacetyl complex in methylene chloride are interpreted in terms of base strength and steric factors. The enthalpy change for pyridine addition to {IrClXCH3[P(C6H5)3]2} (X = Cl, Br, -NCO, NO2, or CH3CO2) in methylene chloride reveals that the cis influence of X is low. Representative examples of the octahedral adducts {IrCl2R[P(C6H5)3] 2·B} have been isolated and characterized. In each case the base B is found to add stereospecifically trans to the substituent R.

AB - The Lewis acid character of a series of coordinatively unsaturated iridium(III) complexes of the type {IrCl2R[P(C6H5)3]2} (R is C(O)CFnH3-n (n = 1, 2, or 3), -S(O)2R′ (R′ = CH3, C2H5, or CF3), or CH3) has been studied by calorimetric and spectroscopic methods. Enthalpy data for addition of pyridine as a function of R are interpreted in terms of a trans influence series for the R groups. This thermochemical trans influence series is compared with that derived from the trends in iridium-chlorine stretching frequencies in model compounds having R trans to Cl. The enthalpy change and equilibrium constant for pyridine addition to the complex in which R = C(O)CF3 were determined in six solvents. The trends in enthalpy changes and equilibrium constants for addition of a series of ten bases to the trifluoroacetyl complex in methylene chloride are interpreted in terms of base strength and steric factors. The enthalpy change for pyridine addition to {IrClXCH3[P(C6H5)3]2} (X = Cl, Br, -NCO, NO2, or CH3CO2) in methylene chloride reveals that the cis influence of X is low. Representative examples of the octahedral adducts {IrCl2R[P(C6H5)3] 2·B} have been isolated and characterized. In each case the base B is found to add stereospecifically trans to the substituent R.

UR - http://www.scopus.com/inward/record.url?scp=33847088769&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33847088769&partnerID=8YFLogxK

M3 - Article

VL - 16

SP - 2606

EP - 2612

JO - Inorganic Chemistry

JF - Inorganic Chemistry

SN - 0020-1669

IS - 10

ER -