Cp2Ti{[OC(O)C5H4]Cr(CO)2NO]}2 and Cp2Ti{[(OC(O)C5H4]Cr(NO)2X}2 syntheses and spectra of chromium–titanium complexes bridged by carboxylate substituted cyclopentadienyl group

Complete demethylation of Cp2Ti(CH3)2 in dichloromethane with 2 M equivalent of [η5-(C5H4COOH)]Cr(CO)2NO (5), [η5-(C5H4COOH)]Cr(NO)2X] (X = Cl 6, X = I 7), and [η5-(C5H4COOH)]W(CO)3CH3 (8); gives Cp2Ti{[OC(O)C5H4]Cr(CO)2NO}2 (13), Cp2Ti{[OC(O)C5H4]Cr(NO)2Cl}2 (14), Cp2Ti{[OC(O)C5H4]Cr(NO)2I}2 (15),and Cp2Ti{[OC(O)C5H4]W(CO)3CH3}2 (16), respectively. The chemical shifts of C(2)–C(5) carbon atoms of compounds 13–15 have been assigned using two-dimensional HetCOR NMR spectroscopy. The assigned chemical shifts were compared with the NMR data of their analogues of ferrocene, and the opposite correlation on the assignments was observed for cynichrodenoyl moieties.