Coordination chemistry of 2,6-dimethanol pyridine with early transition metal alkoxide compounds.

The coordination behavior of the 2,6-dimethanol pyridine (H2-pdm) with Group 4 and 5 metal alkoxides was undertaken through a series of alcoholysis reactions. The products were crystallographically identified as: (OR)2M(μ2-pdm)[(μ-pdm)M(OR)2]2(M = Ti, OR = OPri(1· py), ONep (2· HONep, tol); Zr, OBut(3)), [M3(μ3-pdm)(μ-pdm)2(μ-ONep)2(ONep)4] (M = Zr (4), Hf (5)), [M(μ-pdm)(OR)3]2[M/OR = Nb/OEt (6), and Ta/ONep (7)] where μ = η1,η1,η2(O,N,O′), μ2 = η2,η1,η2(O,N,O′), μ3 = η1,η1,η3(O,N,O′), OEt = OCH2CH3, OPri = OCH(CH3)2, OBut = OC(CH3)3, and ONep = OCH2C(CH3)3. For each complex, pdm was a bichelating (O,N,O′) ligand generating trinuclear species coupled with a variety of additional bridging modes: μ, μ2, and μ3. Further analyses by multinuclear and DOSY NMR studies indicated that the structures were retained in solution. The coordination behavior of 2,6-dimethanolpyridine (H2-pdm) with Group 4 and 5 metal alkoxides was crystallographically determined. The pdm ligand was found to undergo a variety of tridentate, bridging coordination configurations: (OR)2 M(μ2–pdm)[(μ–pdm)M(OR)2]2(shown), M3(μ3–pdm)(μ–pdm)2(OR)6, or [M(μ–pdm)(OR)3]2. [ABSTRACT FROM AUTHOR]