Reactions of 1 equiv of HO(O)P(OtBu)2 with Ti(OR)4 (R = Et, iPr) give the new molecular titanium phosphates [Ti(OR)3O2P(OtBu)2]n (1, R = Et; 2, R = iPr). In the solid state, 2 exists as a centrosymmetric dimer containing five-coordinate metal centers. Addition of 2 equiv of KOEt to an ethanol solution of 1 led to the formation of [Ti2K(OEt)8O2P(OtBu)2]2 (3) and 1 equiv of KO2P(OtBu)2. A single-crystal X-ray structure analysis of 3 revealed that this complex exists in the solid state as a centrosymmetric dimer containing two Ti-centered, face-sharing pseudooctahedra in the unique half of the dimer. Addition of 2 equiv of KOiPr to a 2-propanol solution of 2 led to the formation of KO2P(OtBu)2 (4) and Ti(OiPr)4 in high yield. Cooling a 2-propanol solution of 4 to −80 °C led to crystallization of the solvated tetramer [4·HOiPr3]4 (mp = −30 °C). A single-crystal X-ray structure analysis revealed that this tetramer possesses a cubelike K4O4 core with 4-fold improper rotation symmetry. Multinuclear NMR studies of 1−3 show that the structures of these complexes are dynamic in solution. Crystals of 4 are tetragonal (P42/n) with a = 18.6261(3) Å, c = 14.7114(3) Å, and Z = 8.
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