149856-23-5Relevant articles and documents
Stability of vanadium(II) aryloxides: Synthesis and characterization of sterically protected, neutral and monomeric vanadium(II) aryloxides. Reactivity with the N-N bond of (Me3Si)CH=N=N
Minhas, Ravinder K.,Edema, Jilles J. H.,Gambarotta, Sandro,Meetsma, Auke
, p. 6710 - 6717 (2007/10/02)
The preparation of neutral V(II) aryloxides has been achieved via ligand-replacement reactions on three V(II) complexes (Mz2V(py))2(μ-N2), Mz2V(py)2, and VCl2(TMEDA)2 (Mz = o-Me2NCH2C6H4, TMEDA = N,N,N′,N′-tetramethylethylenediamine) with several phenols, or their corresponding alkali salts. In the case of sterically demanding phenols [2,6-(t-Bu)2-4-MeC6H2OH, 2,6-Ph2PhOH, 2-(MeO)C6H4OH] it was possible to isolate and characterize monomeric and neutral V(II) aryloxides with a variety of coordination geometries. When similar reactions were carried out on the same complexes with less bulky alcohols (2,6-Me2PhOH, PhOH, t-BuOH), monomeric V(III) and dimeric V(III)/V(IV) mixed-valence species were isolated. The crystal structures of the square-planar [2,6-(t-Bu)2-4-MeC6H2O]2V(py) 2 (4), saddle-shape (2,6-Ph2PhO)2V(TMEDA) (5), square-pyramidal (2,6-Ph2PhO)2V(py)3 (6), and octahedral [2-(MeO)C6H4O]2V(TMEDA) (7) were demonstrated by X-ray diffraction analysis. Crystal data are as follows. 4: C40H56VN2O2·(C 7H8)2, Mr = 833.12, triclinic, P1?, a = 9.701(2) A?, b = 15.303(3) A?, c = 9.000(2) A?, α = 101.99(2)°, β= 112.59(2)°, γ = 74.20(2)°, V = 1179.0(4) A?3, Z = 1, λ = 0.710 69 A?, R = 0.053, Rw = 0.068, and GoF = 2.89 for 365 parameters and 3475 out of 4134 unique reflections. 5: C42H42N2O2V, Mr = 657.74, monoclinic, P21/a, a = 16.373(1) A?, b = 11.1624(9) A?, c = 19.536(3) A?, β= 97.35(1)°, V= 3541.3(7) A?3, Z = 4, γ = 0.709 30 A?, R = 0.044, Rw = 0.017, and GoF = 1.63 for 589 parameters and 2714 out of 4603 unique reflections. 6: C51H41N3O2V, Mr = 778.85, monoclinic, C2/c, a = 20.65(2) A?, b = 14.28(1) A?, c = 16.08(1) A?, β = 119.89(7)°, V = 4113.(7) A?3, Z = 4, R = 0.053, Rw = 0.049, and GoF = 1.34 for 259 parameters and 1505 out of 3182 unique reflections. 7: C20H30VN2O4, Mr, = 413.41, orthorhombic,Pna21, a = 13.519(5) A?, b = 13.846(4) A?, c = 11.196(2) A?, V = 2096(1) A?3, Z = 4, R = 0.037, Rw = 0.047, and GoF = 1.96 for 244 parameters and 1669 out of 2116 unique reflections. Reaction of 7 with (Me3Si)CHN2 gave the new diamagnetic and dinuclear complex {[2-(MeO)C6H4O]2V} 2[μ-NNCH-(SiMe3)]2 (13). Complex 13 was co-crystallized in a 1/1 ratio with {[2-(MeO)C6H4O]2V}2[μ-OC 6H4(2-OCH3)]2, which was formed from the thermal degradation of 13 through a complicated reaction. Crystal data for the cocrystallite{[2-MeO)C6H4O]2V} 2[μ-NNCH(SiMe3)]2/{[2-MeO)C 6H4O]2V}2[μ-OC6H 4(2-OCH3)]2 (14) are as follows. 14: C39H45V2N2O10Si, Mr = 831.76, triclinic, P1?, a = 14.443(6) A?, b = 15.039(6) A?, c = 10.679(3) A?, α = 100.66(3)°, β = 97.46(3)°, γ = 113.84(3)°, V = 2030(1) A?3, Z = 2, R = 0.045, Rw = 0.060, and GoF = 2.45 for 488 parameters and 5530 out of 6946 unique reflections.
