The reactions of TiCl 4 and Ti(O i Pr)Cl 3 with 1-3 molar equiv of 2-propanol give the dimeric complexes [TiCl 3 (HO i -Pr)(µ-Cl)] 2 (1), [TiCl 2 (O i Pr)(HO i Pr)(µ-Cl)] 2 (2), and [TiCl 2 (O i Pr)(HO i Pr)(µ-O i Pr)] 2 (3). The reactions are shown to proceed stepwise with the consecutive addition of 2-propanol. Complexes 2 and 3 are dynamic in solution. However, the proton VT NMR studies show that they are static and remain the dimeric features in solution at low temperatures. Two inequivalent methyl environments are observed for the 2-propanol ligand of complex 3, probably due to the intramolecular hydrogen bonding from the isopropanolic hydrogen to the chloride on the second titanium metal center. 2 crystallizes in the orthorhombic space group Pbca with cell parameters of a ) 12.605(3) Å, b ) 12.841(4) Å, c ) 15.414(4) Å, Z ) 4, D calcd ) 1.456 g/cm 3 , R ) 0.049, R w ) 0.062, and G OF ) 1.38. 3 crystallizes in the monoclinic space group P2 1 /c with cell parameters of a ) 9.457(2) Å, b ) 15.277(2) Å, c ) 11.354(4), β ) 112.76(2)°, Z ) 2, D calcd ) 1.305 g/cm 3 , R ) 0.032, R w ) 0.048, and G OF ) 1.29. Through the analysis of the bonding features of the solid-state structures 2 and 3, the relative bonding sequence of -O i Pr > Cl -> HO i Pr > µ--O i Pr > µ-Clis established. This bonding order is useful for the prediction of the geometries of sixcoordinate titanium complexes containing those ligands with the rule "the strong ligand prefers a position trans to the weak ligand in the complexes". Besides, the reaction features demonstrated in this study may apply to the reaction of TiCl 4 or Ti(O i Pr)Cl 3 with diols, especially for chiral diols used as ligands in titanium complexes for various asymmetric syntheses of organic compounds.
A series of titanium(IV) acetylacetonate (acac) complexes, Ti(acac)Cl3 (THF) (2), [Ti(acac)Cl2(THF)]2 (μ‐O) (3), [Ti(O‐i‐Pr)Cl3(acac)]‐(HNEt3+) (5), and Ti(O‐i‐Pr)Cl2 (acac)(THF) (6), were prepared from reactions of TiCl4 or Ti(O‐i‐Pr)Cl3 with 2,4‐pentanedione (Hacac) in CH2Cl2 or THF with or without the presence of NEt3. The x‐ray structural analyses were carried out on complexes 2 and 6. Complex 2 crystallizes in the monoclinic P21/n space group with a = 8.664(1) Å, b = 11.859(1) Å, c = 14.320(1) Å, β = 103.94(1)°, R = 0.0571, Rw = 0.0620, and G of = 1.10. Complex 6 crystallizes also in the monoclinic P21/n space group with a = 9.074(2) Å, b = 11.499(2) Å, c = 16.549(4) Å, β = 101.96(2)°, R = 0.0492, Rw = 0.0671, and Gof= 1.49. Based on the solid state structures of complexes 2 and 6, the relative bonding order of −O‐i‐Pr > Cl− > acac− THF is established.
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