IR spectroscopic investigations into reactions between unsaturated titanium complexes and CO or N2 in liquid xenon or heptane

Abstract The reactions of Cp∗ 2 TiR compounds with CO in liquid xenon (LXe) or heptane were studied by IR spectroscopy in special high-pressure cells. All complexes incorporate a single CO molecule to fill up their coordination sphere, forming Cp∗ 2 TiR(CO) intermediates. These species undergo secondary reactions at elevated temperatures, such as disproportionation to Ti(II) and Ti(IV) complexes. The formation of the 18 VE species Cp∗ 2 Ti(CO) 2 seems to be the driving force of the observed reactions. A similar behavior was found in the reaction of Cp∗ 2 TiH with dinitrogen, where the adduct Cp∗ 2 TiH(N 2 ) and its 14 15 N 2 isotopomer was identified together with Cp∗ 2 Ti(N 2 ) 2 . In addition to these orientating experiments, the stable 15 VE Cp∗FvTi (Fv = η 6 C 5 Me 4 CH 2 ) and 16 VE species Cp∗AdTi (Ad = η 7 C 5 Me 3 (CH 2 ) 2 ) show the addition of carbon monoxide to form new, reactive titanium carbonyls, which undergo ligand exchange reactions at higher temperatures and form Cp∗ 2 Ti(CO) 2 as one of the final products.