"Magnetc Torque in Superoxide Ion is the Main Driving Force of Dioxygen Activation in Aerobic Life"

Abstract

Dioxygen (O 2 molecule) is a biradical with two unpaired electron spins, while most of organic substances have all electron spins paired; therefore reactions catalysed by oxidases and oxygenases have to involve intersystem crossing (ISC), that is a total spin change in the state multiplicity during bio oxidation. These reactions are strictly forbidden in the ordinary non-relativistic quantum chemistry. In order to overcome this severe quantum prohibition and sovereign limitation of dioxygen-induced metabolism, oxygenation enzymes require usually a redox cofactor or paramagnetic metal cofactor for effective catalysis. The spin-containing metal ions have no formal spin prohibition for reactions with dioxygen. But many oxidative enzymes include the metal-free flavin or pterin cofactors; their catalytic activity in respect to O 2 still remains mysterious in modern biochemistry and medicine. Last decades have shown, that some oxygenases can catalyse dioxygen incorporation into organic substrates even in the absence of any enzymatic cofactor. The intriguing mechanism followed by those cofactor-free enzymes which enable to provide ISC and overcome spin prohibition has been unraveled recently on the ground of common idea about specific magnetic properties of dioxygen open shell. Similar spin-orbit coupling effects are typical for O 2 molecule and for some reactive oxygen species (ROS). These spin-orbit torques are vitally decisive forces for all aerobic life.

INTERACTION OF QUINTET OXYGEN O2(5Пg) WITH BENZENE IN THE RAREFIED GAS PHASE

“…3) and stable quintet product (Fig. 2) exhibit peculiar properties, which differe from all stidued associates between triplet O2 (X 3 Σg − ) molecule and various organic and inorganic species, including transition metal compounds with high electronic spin [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22].…”