- Synthesis of an organogallium(I) compound [Ga(CH2CMe2Ph)]n with EPR spectral evidence for gallium clusters
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The organogallium(I) compound [Ga(CH2CMe2Ph)]n has been prepared by the reduction of Ga(CH2CMe2Ph)2Cl by using either sodium or lithium with naphthalene in THF. The yellow dihydronaphthalene gallium(III) intermediate M2{C10H8[Ga(CH2CMe 2Ph)2Cl]2} initially formed at -78°C but then decomposed at higher temperatures to form [Ga(CH2CMe2Ph)]n, Ga(CH2CMe2Ph)3 and MCl. EPR spectra, which were recorded as the two yellow intermediates Na2{C10H8[Ga(CH2CMe 2R)2Cl]2} (R = Ph, Me) decomposed, indicated the presence of radicals. The first and second derivatives of the EPR signals, line-widths, g-values and hyperfine coupling constants are consistent with the radicals being clusters of organogallium species. The experimental spectra were simulated by the superposition of two spectra, a single Gaussian shaped line with a peak-to-peak width of 14 mT (92%) with the spectrum of five equivalent gallium nuclei, A = 2.1 mT (8%). The even number of lines observed in the experimental spectra indicate an odd number of gallium nuclei with at least five being required to give the number of observed lines.
- Beachley Jr.,Noble, Matthew J.,Allendoerfer, Robert D.
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- Organogallium compounds containing the neophyl substituent. Crystal and molecular structure of trans-[(PhMe2CCH2)2GaN(H)(Pr)]2
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A series of organogallium compounds which contain the neophyl substituent including Ga(CH2CMe2Ph)3, Ga(CH2CMe2Ph)2Cl, Ga(CH2CMe2Ph)Cl2, and (PhMe2CCH2)2GaN(H)(Pr) have been prepared in high yield by reactions typical of organogallium chemistry. The characterization data include elemental analyses, melting points, NMR and IR spectroscopic studies, and cryoscopic molecular weight studies. All data are consistent with the conclusions that Ga(CH2CMe2Ph)3 is monomeric in benzene solution whereas Ga(CH2CMe2Ph)2Cl, Ga(CH2CMe2Ph)Cl2, and (PhMe2CCH2)2GaN(H)(Pr) are dimeric. The gallium amide [(PhMe2CCH2)2GaN(H)(Pr)]2 crystallizes in the centrosymmetric triclinic space group P1 (No. 2) with a = 10.739 (2) A?, b = 10.844 (2) A?, c = 11.125 (2) A?, α = 69.14 (1)°, β = 62.96 (1)°, γ = 76.74 (1)°, V = 1074.7 (3) A?3, and Z = 1. Diffraction data (Mo Κα, 2θ = 5-50°) were collected on a Siemens R3m/V automated four-circle diffractometer, and the structure was refined to R = 3.57percent and wR = 3.46percent for all 3803 unique reflections (R = 2.52percent, wR = 2.62percent for those 3111 data with \Fo\ >; 6σ(|Fo|)). The molecule lies on a crystallographic inversion center and thus has a strictly planar Ga2N2 core. Distances of interest include Ga-CH2CMe2Ph = 1.992 (2) and 1.994 (3) A? and Ga-N(bridging) = 2.013 (2) and 2.029 (2) A?.
- Beachley Jr.,Noble,Churchill, Melvyn Rowen,Lake, Charles H.
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p. 1051 - 1055
(2008/10/08)
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