15690-50-3Relevant academic research and scientific papers
Molecular dynamics in solid bis(η-arene)molybdenum complexes studied by solid-state deuterium nuclear magnetic resonance spectroscopy
O'Hare, Dermot,Heyes, Stephen J.,Barlow, Stephen,Mason, Susan
, p. 2989 - 2993 (1996)
Variable-temperature solid-state 2H NMR spectra have been recorded on microcrystalline samples of [Mo(η-C6D6)2], [Mo{η-C6D3(CD3)3-1,3,5} 2] and [ZrS2/
15N Nuclear Polarisation in Nitration and Related Reactions. Part 5. The Borderline between the Classical and the Electron Transfer Mechanisms in Nitration by the Nitronium Ion
Johnston, James F.,Ridd, John H.,Sandall, John P. B.
, p. 623 - 628 (2007/10/02)
The nitration of p-xylene, mesitylene, naphthalene, 2H8>naphthalene, durene and some related compounds has been followed by 15N NMR spectroscopy in a mixture of trifluoroacetic acid and nitromethane containing sufficient sodium azide to inhibit nitrous acid catalysed nitration.Significant 15N nuclear polarisation occurs with durene and the naphthalenes and has been analysed by comparison with theoretical curves leading to the calculation of enhancement coefficients.The results indicate that a small part of the reaction of naphthalene with nitronium ions under these conditions involves direct electron transfer between the reactants before the formation of the Wheland intermediate.The extent of this electron transfer is much greater than expected from Marcus theory calculations based on an outer-sphere electron transfer (ET) reaction: the discrepancy is discussed in terms of the initial interaction between the reactants and the solvent effects on the equilibrium constant for the electron transfer.
Synthesis of group 13 element metallacarboranes and related structure-reactivity correlations
Schubert, David M.,Bandman, Marc A.,Rees Jr., William S.,Knobler, Carolyn B.,Lu, Paul,Nam, Wonwoo,Hawthorne, M. Frederick
, p. 2046 - 2061 (2008/10/08)
Synthesis, reactivity, and structural characterization studies of a number of group 13 metallacarborane species are described. These include studies of the icosahedral aluminacarborane closo-3-Et-3,1,2-AlC2B9H11 (1a). Compound 1a reacts with Lewis bases to form adducts of the type 2L-1a (L = Lewis base). The reaction of 1a with excess PEt3 results in the rapid formation of endo-10-{AlEt(PEt3)2}-7,8-C2B9H 11 (3). The novel sandwich species commo-3,3′-Al[{exo-8,9-(μ-H)2-AlEt 2-3,1,2-AlC2B9H9)}(3,1,2-AlC 2B9H11)] (4) results from thermal dimerization of 1a. The related sandwich anions [commo-3,3′-Al(3,1,2-AlC2B9H11) 2]- ([5]-) and [commo-3,3′-Ga(3,1,2-GaC2B9H11) 2]- ([6]-) have been prepared. The full details of the synthesis and structural characterization of σ-bonded species nido-6,9-(μ-AlEt-(OEt2))-6,9-C2B8H 10 (8), [Al(η2-6,9-C2B8H10) 2]- ([10]-), and [Al(η2-2,7-C2B6H8) 2]- ([11]-) are reported. The metallacarboranes 3, 4, [5]-, [6]-, 8, [10]-, and [11]- were characterized by a combination of spectroscopic techniques and by single-crystal X-ray diffraction studies. Crystallographic parameters are as follows: 3, P21/n, a = 9.722 (3) A?, b = 16.135 (4) A?, c = 16.984 (5) A?, β = 90.246 (9)°, V = 2652 A?3, Z = 4, R = 0.064, Rw = 0.082 for 3394 independent reflections with I > 3σ(I); 4, P21/n, a = 7.122 (2) A?, b = 27.668 (8) A?, c = 11.629 (3) A?, β = 96.246 (5)°, V = 2288 A?3, Z = 4, R = 0.065, Rw = 0.075, GOF = 2.39 for 2137 independent reflections; Tl[5]·2/3C7H8, P1, a = 11.347 (2) A?, b = 11.748 (2) A?, c = 12.708 (2) A?, α = 92.429 (6)°, β = 90.876 (6)°, γ = 93.343 (5)°, V = 1689 A?3, Z = 3, R = 0.057, Rw = 0.064, GOF = 1.57 for 1941 independent reflections; Tl[6], P1, a = 6.9564 (6) A?, b = 11.0466 (9) A?, c = 12.0287 (10) A?, α = 102.088 (2)°, β = 95.484 (2)°, γ = 94.687 (3)°, V = 894 A?3, Z = 2, R = 0.041, Rw, = 0.054, GOF = 2.03 for 2733 independent reflections; 8·1/2C6H6, A1, a = 13.964 (3) A?, b = 15.966 (4) A?, c = 8.550 (2) A?, α = 92.227 (8)°, β = 86.689 (7)°, γ = 102.060 (8)°, V = 1862 A?3, Z = 4 (reduced cell: a = 8.552 A?, b = 8.909 A?, c = 13.967 A?, α = 99.172°, β = 93.323°, γ = 116.428°, V = 930.9 A?3, Z = 2) R = 0.061, Rw = 0.081, GOF = 2.85 for 2338 independent reflections; [(PPh3)2N][10], P21/c, a = 16.378 (3) A?, b = 18.781 (3) A?, c = 14.806 (3) A?, β = 90.197 (5)°, V = 4554 A?3, Z = 4, R = 0.078, Rw = 0.088, GOF = 2.0 for 2128 independent reflections; [Na][11], P21, a = 10.035 (2) A?, b = 12.433 (3) A?, c = 11.690 (3) A?, β = 111.019 (7)°, V = 1367 A?3, Z = 4, R = 0.049, Rw = 0.059, GOF = 2.08 for 2156 independent reflections. The compound Tl[5]°2/3C7H8 contains the thallium(I)-arene complex Tl(η6-MePh). Compounds 1a and 4 were shown to catalyze the exchange of carborane B-H and arene C-D bonds as well as the polymerization of selected olefins under mild homogeneous conditions. Bonding and the varying degrees of distortion from idealized closo and commo geometries displayed by 3,4, [5]-, and [6]- are discussed. Species 8, [10]-, and [11]- contain Al-C σ-bonded aluminum-carborane connectivities. Compound 8 exhibits rapid exchange of aluminum-coordinated ether in solution, and the compound nido-6,9-(μ-AlEt-(C4H8O))-6,9-C2B 8H10 (9) was prepared by ether exchange of 8 in tetrahydrofuran/toluene. Anion [11]-undergoes rapid enantiomer interconversion in solution at room temperature.
