The photochemical treatment of m 3 -alkylidyne complexes [{TiCp*(m-O)} 3 (m 3 -CR)] (R H (1), Me (2), Cp* h 5 -C 5 Me 5 ) with the amines (2,6-Me 2 C 6 H 3 )NH 2 , Et 2 NH, and Ph 2 NH and the imine Ph 2 C NH leads to the partial hydrogenation of the alkylidyne moiety that is supported on the organometallic oxide, [Ti 3 Cp* 3 O 3 ], and the formation of new oxoderivatives [{TiCp*(m-O)} 3 -(m-CHR)(R'NR'')] (R'' 2,6-Me 2 C 6 H 3 , R' H, R H (3), Me (4); R' R'' Et, R H (5), Me (6); R' R'' Ph, R H (7), Me (8)) and [{TiCp*(m-O)} 3 (m-CHR)(NCPh 2 )] (R H (9), R Me (10)), respectively. A sequential transfer hydrogenation process occurs when complex 1 is treated with tBuNH 2 , which initially gives the m-methylene [{TiCp*(m-O)} 3 (m-CH 2 )(HNtBu)] (11) complex and finally, the alkyl derivative [{TiCp*(m-O)} 3 (m-NtBu)Me] (12). Furthermore, irradiation of solutions of the m 3 -alkylidyne complexes 1 or 2 in the presence of diamines o-C 6 H 4 (NH 2 ) 2 and H 2 NCH 2 CH 2 NH 2 (en) affords [{TiCp*(m-O)} 3 (m 3 -h 2 -NC 6 H 4 NH)] (13) and [{TiCp*(m-O)} 3 (m 3 -h 2 -NC 2 H 4 NH)] (14) by either methane or ethane elimination, respectively. In the reac-tion of 1 with en, an intermediate complex [{TiCp*(m-O)} 3 (m-CH 2 )(NH-CH 2 CH 2 NH 2 )] (15) is detected by 1 H NMR spectroscopy. Thermal treatment of the complexes 4 ± 10 quantitatively regenerates the starting m 3 -alkylidyne compounds and the amine R' 2 NH or the imine Ph 2 CNH; however, heating of solutions of 3 or 4 in [D 6 ]benzene or a equimolecular mixture of both at 170 8C produces methane, ethane, or both, and the complex [{TiCp*-(m-O)} 3 {m 3 -h 2 -NC 6 H 3 (Me)CH 2 }] (16). The molecular structure of 8 has been established by single-crystal X-ray analysis. Keywords: hydrogenation ¥ N ligands ¥ oxo ligands ¥ titanium Scheme 1. Chemical reactivity of the m 3 -alkylidyne groups at the Ti 3 O 3 core with ketones, N-benzilidene(phenyl)amine and isocyanides.