Playing Catch with Electrons: A Dynamic Metaphor for Chemical Bonding with an Extension of the Tunneling Model to Gas-Phase Molecules.

Quantum mechanical electron tunneling is explored as the mediator of chemical bonding. Three topics are addressed. First, a baseball game-of-catch metaphor is employed to elucidate the physics of chemical bonding. According to this metaphor, a baseball player, a baseball, and the act of throwing a baseball are analogous to an atom, an electron, and the act of electron tunneling. Using this framework, the tunneling physics of covalent, polar covalent, ionic, and hydrogen bonding is clarified. Second, gas-state energies associated with frontier orbital positioning are established and are used in the chemical bond tunneling assessment of four homopolar bonds, H-H, N≡N, O=O, and F-F, and four heteropolar bonds, H-F, H-Cl, H-Br, and H-I. Third, a new procedure for estimating solid-state tunneling parameters is introduced, involving quantum confinement of gas-state energy frontier orbitals.