Investigations of dioxygen reactivity with synthetic models of the metalloproteins hemocyanin and cytochrome c oxidase

S. Fox, A. Nanthakumar, N. Wei, N. Narasimha Murthy, K. D. Karlin
1993 Pure and Applied Chemistry  
Synthetic, chemical, and low-temperature stopped-flow kinetic studies in EtCN indicate initial formation of the 1:l 0 2 adduct [(TMPA)Cu(O2)]+ (4), and subsequent formation of the 2:1 0 2 adduct [( ( T M P A > C U ]~( O~) ]~+ (2) from [ (TMPA)Cu(RCN)]+ (1) and 0 2 ; vacuum-cycling experiments demonstrate reversible binding of a. An X-ray structural study of 2 revealed a trans-p-1, 2 configuration for the 022-ligand; thus, the reactivity of 1 with 0 2 models the function of hemocyanin. Reaction
more » ... mocyanin. Reaction of 1 with (Fg-TPP)Fe(II)pip2 (5) and 0 2 , yielded the structurally characterized p-0x0 [(Fg-TPP)Fe(III)-0-Cu(II)(TMPA)]+ (6) species, which was protonated to yield the p-hydroxo bridged analogue [(Fg TPP)Fe-(OH)-Cu(TMPA)I2+ (9); these complexes may model intermediates in the OZ reduction cycle, and/or the "resting-state", of cytochrome c oxidase.
doi:10.1351/pac199365112335 fatcat:5drnea6p75exfae25sv3kek5q4