Reactivity Studies of Para-Hydrogen with μ₃-Quinolyl Triosmium Clusters

Abstract

The reactions of the cluster complexes Os 3 (CO) 9 (μ 3 -η 3 -C 9 H 7 (4-CH 3 )N)(μ-H)( 1 ), Os 3 (CO) 9 (μ 3 -η 2 -C 9 H 5 (n-NH 2 )N)(μ-H) ( n = 3, 2, n = 5, 3 ), Os 3 (CO) 9 (μ 3 -η 2 -C 9 H 6 (4-C(CH 3 ) 2 CN)(5-NH 2 )N)(μ-H) ( 4 ), and Os 3 (CO) 9 (μ 3 -η 2 -C 9 H 6 (4-C(CH 3 ) 2 CN)(5-F)N)(μ-H) ( 5 ) with para-hydrogen have been studied at ∼3 atm and 90−110 °C. In all cases, reaction at the metal core is the initial product and polarization enhanced polyhydride intermediates are observed. The chemical shifts and relative intensities of these resonances are used to extract mechanistic information about the reactivity of 1 − 5 . As with previous studies on related electron-deficient complexes, 3 − 5 show reactivity that is very sensitive to the substituent in the 5-position.