Nuclear magnetic resonance studies of ligand-exchange processes. II. Kinetics of configurational rearrangement for some mixed β-diketonate complexes of gallium(III)

Thomas J. PinnaVaia, John M. Sebeson, David Case

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

Nmr studies of Ga(acac)2(hfac) in dichloromethane and of Ga(acac)2(bzbz) in benzene, where acac = acetylacetonate, hfac = hexafluoroacetylacetonate, and bzbz = dibenzoylmethanate, have shown that the molecules undergo intramolecular configurational rearrangement processes which result in exchange of nonequivalent terminal methyl groups on the acac ligands. First-order rate constants for the rearrangement processes have been determined by line-broadening techniques. The rate of methyl group exchange at 25° for Ga(acac)2(hfac) is ca. 104 times larger than the rate for Ga(acac)2(bzbz). Activation energies and activation entropies were found to be, respectively: 14.5 ± 1.1 kcal/mol and 1.7 ± 4.4 eu for Ga(acac)2(hfac); 20.6 ± 2.7 kcal/mol and 3.5 ± 8.0 eu for Ga(acac)2(bzbz). The activation energies are discussed briefly and are compared with available parameters for terminal group exchange in other group IIIb metal γ-diketonates.

Original languageEnglish (US)
Pages (from-to)644-648
Number of pages5
JournalInorganic Chemistry
Volume8
Issue number3
DOIs
StatePublished - Mar 1 1969
Externally publishedYes

Fingerprint

Gallium
gallium
Activation energy
Nuclear magnetic resonance
Ligands
nuclear magnetic resonance
ligands
Kinetics
Methylene Chloride
kinetics
Benzene
Rate constants
Entropy
Metals
Chemical activation
activation energy
Molecules
benzene
activation
entropy

All Science Journal Classification (ASJC) codes

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry

Cite this

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title = "Nuclear magnetic resonance studies of ligand-exchange processes. II. Kinetics of configurational rearrangement for some mixed β-diketonate complexes of gallium(III)",
abstract = "Nmr studies of Ga(acac)2(hfac) in dichloromethane and of Ga(acac)2(bzbz) in benzene, where acac = acetylacetonate, hfac = hexafluoroacetylacetonate, and bzbz = dibenzoylmethanate, have shown that the molecules undergo intramolecular configurational rearrangement processes which result in exchange of nonequivalent terminal methyl groups on the acac ligands. First-order rate constants for the rearrangement processes have been determined by line-broadening techniques. The rate of methyl group exchange at 25° for Ga(acac)2(hfac) is ca. 104 times larger than the rate for Ga(acac)2(bzbz). Activation energies and activation entropies were found to be, respectively: 14.5 ± 1.1 kcal/mol and 1.7 ± 4.4 eu for Ga(acac)2(hfac); 20.6 ± 2.7 kcal/mol and 3.5 ± 8.0 eu for Ga(acac)2(bzbz). The activation energies are discussed briefly and are compared with available parameters for terminal group exchange in other group IIIb metal γ-diketonates.",
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Nuclear magnetic resonance studies of ligand-exchange processes. II. Kinetics of configurational rearrangement for some mixed β-diketonate complexes of gallium(III). / PinnaVaia, Thomas J.; Sebeson, John M.; Case, David.

In: Inorganic Chemistry, Vol. 8, No. 3, 01.03.1969, p. 644-648.

Research output: Contribution to journalArticle

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Y1 - 1969/3/1

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