Transport of hydrogen atoms plays a key role in chemical and biological processes involving metabolism of molecular hydrogen. Several 'gas-phase' and more intricate organometallic models (mimics of the hydrogenase enzyme) are developed to show the intriguing role of the molecular hydrogen as a third party in the pass-on transfer of hydrogen atoms. This hydrogen assisted transport (HAT) mechanism is based on the current understanding of the hydrogen exchange reactions and it is believed to be applicable to certain H/D-isotope exchange processes and remote transport of H-atoms. Published by Elsevier B.V.