Titanium Alkoxide Complexes: Condensed Phase and Gas Phase Comparisons

The complex [Ti(2,4-dimethyl-2,4-pentanediolate)2]2 (1) has been synthesized from [Ti(OiPr)4] by transesterification
with a stoichiometric amount of 2,4-dimethyl-2,4-pentanediol. We have characterized complex 1 in the solid
state by single-crystal X-ray diffraction and in the gas phase by desorption chemical ionization mass spectrometry
(DCI-MS). The structural and mass spectrometric data show complex 1 to be stable as a dimer in both the solid
and gas phases. The retention of dimeric nuclearity in the gas phase sets complex 1 apart from other simple
titanium alkoxide complexes [Ti(OiPr)4] and [Ti(OMe)4]4 that give rise to respective families of molecular ions
in the DCI-MS experiment. The highest mass molecular ions for Ti alkoxide complexes in the gas phase may
reveal the highest nuclearity that these complexes achieve in condensed phases. According to this interpretation
the complex [Ti(OiPr)4] is principally dimeric in the gas phase and probably also in the pure liquid phase and
should be represented by the formula [Ti(OiPr)4]2.