I will discuss a role of quantum indistinguishability in chemical bond-breaking processes. Specifically, I will argue that chemical reactions involving small symmetric molecules require a full quantum treatment of collective nuclear degrees of freedom beyond the conventional Born-Oppenheimer description. I will present physical arguments for a “Quantum Dynamical Selection” (QDS) conjecture that precludes processes that involve direct transitions from orbitally non-symmetric molecular states. QDS leads to a number of striking experimental predictions, such as e.g., a differential chemical reactivity of para- and ortho-hydrogen, a mechanism for inducing inter-molecular quantum entanglement of nuclear spins, and a new mass-independent isotope fractionation mechanism, among others.
Leo Radzihovsky 
