An investigation into the photochemical reactions of M(η5-C5H5)(CO)4 and M(η5-C9H7)(CO)4 (M = Nb or Ta) with H2 and N2 in polyethylene matrices and liquid xenon at low temperature

An investigation into the photochemical reactions of MCp(CO)4 (Cp = η5-C5H5) and M(η5-C9H7)(CO)4 (η5-C9H7 = indenyl; M = Nb or Ta) with CO, H2 and N2 in solution at room temperature

“…As 1A decays, new IR bands due to both the non-classical NbCp(CO) 3 (η 2 -H 2 ) and the classical NbCp(CO) 3 H 2 are observed. These results are consistent with our previous low temperature polymer studies 34 (see Table 1). Formation of a dihydride by third row elements is consistent with results seen for Group 7 and Group 8 compounds.…”

“…As 2A and 4A decay new ν(C-O) bands at wavenumbers higher than those of the parent species appear. This indicates oxidation of the metal centre, and these stretches can be assigned to formation of the classical dihydride complexes TaCp(CO) 3 H 2 2C and Ta(η 5 -C 9 H 7 )(CO) 3 H 2 4C, which are consistent with previous low temperature 34 and room temperature studies. However, as 3A decays, the growth of three new carbonyl stretches at band positions lower than those of the parent is observed, and therefore these bands can be assigned to the nonclassical complex, Nb(η…”

“…30 times more reactive than NbCp(CO) 3 (η 2 -H 2 ). Although we were unable to compare the lifetimes of Ta(η 5 -C 9 H 7 )-(CO) 3 H 2 and TaCp(CO) 3 H 2 using our TRIR apparatus, our previous polymer experiments 34 have shown that the reactivities of these dihydride complexes follow the trends observed in this paper.…”

“…These new bands can be assigned to Ta(η 5 -C 9 H 7 )-(CO) 3 (N 2 ) 4B by comparison with our low temperature PE matrix results. 34 Comparable results were obtained following irradiation of 1, 2 and 3 in n-heptane doped with N 2 , with the heptane complexes (1A, 2A and 3A) being formed initially and the dinitrogen substituted complexes (1B, 2B and 3B) growing in as the n-heptane complexes decay. The IR band positions of these complexes are collected in Table 1.…”

“…34 we have described the characterisation of MCpЈ(CO) 3 (N 2 ) (CpЈ = Cp or indenyl; M = Nb or Ta), NbCpЈ(CO) 2 (N 2 ) 2 , TaCpЈ(CO) 3 H 2 , Nb(η 5 -C 9 H 7 )(CO) 3 (η 2 -H 2 ), NbCp(CO) 3 (η 2 -H 2 ) and NbCp-(CO) 3 H 2 following irradiation of MCpЈ(CO) 4…”