SYNTHESIS AND CHARACTERIZATION OF ALKALI-METAL TITANIUM ALKOXIDE COMPOUNDS LITI(O-I-PR)5, NATI(O-I-PR), KTI(O-I-PR)5 - SINGLE-CRYSTAL X-RAY-DIFFRACTION STRUCTURE OF [LITI(O-I-PR)5]2

The series [MTi(O-i-Pr)5], M = Li, Na, or K, has been prepared by the reaction of MO-i-Pr with Ti(O-i-Pr)4. A single-crystal X-ray diffraction study revealed that [LiTi(O-i-Pr)5] crystallizes from toluene at −30 °C in the monoclinic space group P21/n, with unit cell dimensions a = 11.440 (8) Å b = 16.396 (13) Å, c = 11.838 (8) Å,β= 92.59 (5)°, and Z = 4, as a dimer containing two approximately trigonal-bipyramidal titanium centers linked by lithium bridges. In benzene solution, all three compounds are dimeric, as revealed by cryoscopic molecular weight determination, and all three undergo an alkoxide ligand exchange process that is rapid on the 1H NMR time scale at room temperature. The positions of v(M—O) are assigned based on the low-energy shifts observed upon deuteriation of the isopropoxide ligands. © 1990, American Chemical Society. All rights reserved.