Frontier Orbitals, Combustion and Redox Transfer from a Fermionic-Bosonic Orbital Perspective

Oxygenations are highly exergonic, yet combustion of organic matter is not spontaneous in an atmosphere that is 21% O2. Electrons are fermions with a quantum spin number s of 1/2ħ. An orbital containing a single electron with s = 1/2 is fermionic. Orbitals can contain a maximum of two electrons with antiparallel spins, i.e., spin magnetic quantum numbers ms of 1/2 and -1/2. An orbital filled by an electron couple has s = 0 and bosonic character. The multiplicity of a reactant is defined as |2(S)| + 1 where S is the total spin quantum number. The Wigner spin conservation rules state that multiplicity is conserved. The transmission coefficient κ of absolute reaction rate theory also indicates the necessity for spin conservation. Burning is fermionic combustion that occurs when sufficient energy is applied to a bosonic molecule to cause homolytic bond cleavage yielding fermionic products capable of reaction with the bifermionic frontier orbitals of triplet multiplicity O2. Neutrophil leucocytes kill microorganisms by bosonic combustion and employ two mechanisms for changing the multiplicity of O2 from triplet to singlet. Microorganisms, composed of bosonic singlet multiplicity molecules, do not directly react with bifermionic O2, but are highly susceptible to electrophilic attack by bosonic electronically excited singlet molecular oxygen (1O2*). Hydride ion (H-) transfer is the common mode of cytoplasmic redox metabolism. Bosonic transfer of an orbital electron couple protects from damage by obviating fermionic reaction with bifermionic O2. Bosonic coupled electron transfer raises the consideration that quantum tunneling might be involved in facilitating such redox transfer.