TY - JOUR
T1 - Tungsten(VI) metallacarborane imido complexes; hydrogen bonding to a bent imido ligand in {W(Nt(Bu)2[N(H)C(Me)NHtBu](C2 B9H11}
AU - Batsanov, A. S.
AU - Goeta, A. E.
AU - Howard, J. A.K.
AU - Hughes, A. K.
AU - Johnson, A. L.
AU - Wade, K.
PY - 2001/6/21
Y1 - 2001/6/21
N2 - The amine elimination reaction of W(NtBu)2(NHtBu)2 with the di-basic carborane acid nido-7,8-C2B9H13 generates the tungsten(IV) carborane complex, [W(NtBu)(NHtBu)2(C2B9 H11] 1, in which a C2B9H11 ligand has replaced one imido ligand. One of the remaining amido ligands can be substituted by acidic functions, thus 2,6-dimethylphenol yields [W(NtBu)(NHtBu)(2,6-Me2C6 H3O)(C2B9H11)] 2, and water gives the μ-oxo complex {[W(NtBu)(NHtBu)(C2B9 H11)]2(μ-O)} 3 as a mixture of racemic and meso diastereomers. Complexes 1 and 2 have been characterised by single crystal X-ray diffraction, revealing that replacing an amido ligand in 1 by a weaker π-donor phenoxide in 2 results in shorter metal-amido and metal-dicarbollide distances. Substitution of one amido ligand in 1 by a chloro ligand is achieved using Me3SiCl giving [W(NtBu)(NHtBu)Cl(C2B9 H11)] 4. Insertion of acetonitrile into the tungsten amido bond, followed by proton transfer gives {W(NtBu)2[N(H)C(Me)NHtBu](C2 B9H11)} 5, the N-tert-butyl acetamidine adduct of the unknown M(1σ2π)3 complex [W(NtBu)2(C2B9H11)]. A structural study by X-ray diffraction reveals tat compound 5 contains one short linear (W-N 1.750(3) Å; W-N-C 173.8(3)°) and one longer bent (1.795(3) Å, 151.4(3)°) imido ligand, with a hydrogen bond between the amidine and bent imido ligand, demonstrating for the first time that a sp2 hybridised bent imido ligand can act as a hydrogen bond acceptor.
AB - The amine elimination reaction of W(NtBu)2(NHtBu)2 with the di-basic carborane acid nido-7,8-C2B9H13 generates the tungsten(IV) carborane complex, [W(NtBu)(NHtBu)2(C2B9 H11] 1, in which a C2B9H11 ligand has replaced one imido ligand. One of the remaining amido ligands can be substituted by acidic functions, thus 2,6-dimethylphenol yields [W(NtBu)(NHtBu)(2,6-Me2C6 H3O)(C2B9H11)] 2, and water gives the μ-oxo complex {[W(NtBu)(NHtBu)(C2B9 H11)]2(μ-O)} 3 as a mixture of racemic and meso diastereomers. Complexes 1 and 2 have been characterised by single crystal X-ray diffraction, revealing that replacing an amido ligand in 1 by a weaker π-donor phenoxide in 2 results in shorter metal-amido and metal-dicarbollide distances. Substitution of one amido ligand in 1 by a chloro ligand is achieved using Me3SiCl giving [W(NtBu)(NHtBu)Cl(C2B9 H11)] 4. Insertion of acetonitrile into the tungsten amido bond, followed by proton transfer gives {W(NtBu)2[N(H)C(Me)NHtBu](C2 B9H11)} 5, the N-tert-butyl acetamidine adduct of the unknown M(1σ2π)3 complex [W(NtBu)2(C2B9H11)]. A structural study by X-ray diffraction reveals tat compound 5 contains one short linear (W-N 1.750(3) Å; W-N-C 173.8(3)°) and one longer bent (1.795(3) Å, 151.4(3)°) imido ligand, with a hydrogen bond between the amidine and bent imido ligand, demonstrating for the first time that a sp2 hybridised bent imido ligand can act as a hydrogen bond acceptor.
UR - http://www.scopus.com/inward/record.url?scp=0034743851&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:0034743851
SN - 1470-479X
SP - 1210
EP - 1217
JO - Journal of the Chemical Society, Dalton Transactions
JF - Journal of the Chemical Society, Dalton Transactions
IS - 8
ER -