110173-58-5Relevant articles and documents
Substitution chemistry of MM quadruply bonded complexes (M = Mo or W) supported by the anion of 2-hydroxy-6-methylpyridine
Brown, Douglas J.,Chisholm, Malcolm H.,Gribble, Christopher W.
, p. 1793 - 1801 (2008/02/06)
The compounds M2(mhp)4, where M = Mo or W and mhp is the anion formed from deprotonation of 2-hydroxy-6-methylpyridine, are shown to react with carboxylic acids RCOOH to give an equilibrium mixture of products M2(O2CR)n(mhp)4-n where R = 2-thienyl and phenyl. The equilibrium can be moved in favor of M 2(O2CR)4 by the addition of excess acid or by the favorable crystallization of these products. The latter provides a facile synthesis of the W2(O2CR)4 compound where R = 9-anthracene. Reactions involving 2,4,6-triisopropyl benzoic acid, TiPBH, yield M2(TiPB)2(mhp)2 compounds as thermodynamic products. Reactions involving Me3OBF4 (1 and 2 equiv.) yield the complexes Mo2(mhp)3(CH3CN) 2BF4 and Mo2(mhp)2(CH 3CN)4(BF4)2, respectively. The latter compound has been structurally characterized and shown to have mirror symmetry with two cis mhp ligands: MoMo = 2.1242(5) A, Mo-O = 2.035(2) A, Mo-N(mhp) = 2.161(2) A, and Mo-N(CH3CN) = 2.160(3) and 2.170(3) A. Reactions involving Mo2(mhp)3(CH 3CN)22+ and Mo2(mhp) 2(CH3CN)42+ with nBu 4NO2CMe (1 and 2 equiv.) yield the complexes Mo 2(mhp)3(O2CMe) and Mo2(mhp) 2(O2CMe)2 which are shown to be kinetically labile to ligand scrambling. Reactions between Mo2(mhp) 3(CH3CN)2+BF4 - (2 equiv.) and [nBu4N+] 2[O2C-X-CO2]2- yielded dimers of dimers [Mo2(mhp)3]2(-O2C-X-CO 2] where X = nothing, 2,5- or 3,4-thienyl and 1,4-C6H 4. Reactions between Mo2(mhp)2(CH 3CN)42+(BF4-) 2 and tetra-n-butylammonium oxalate and terephthalate yield compounds [Mo(mhp)2bridge]n which by MALDI-TOF MS are proposed to be a mixture of molecular squares (n = 4) and triangles (n = 3) along with minor products of [Mo2(mhp)3]2(bridge) and Mo 2(mhp)4 that arise from ligand scrambling. The Royal Society of Chemistry.
