Cleaving C-H bonds with hyperthermal H₂: Facile chemistry to cross-link organic molecules under low chemical- and energy-loads

A facile method for cross-linking organic molecules has been developed by computational modeling, instrumentation design, and experimental research. Briefly, organic molecules are hit by H₂ with controllable kinetic energy in our novel apparatus where a high flux of hyperthermal H₂ is generated. When a C-H bond of the organic molecule is hit by H₂ at about 20 eV, efficient kinematic energy-transfer in the H₂→H collision facilitates the C-H dissociation with nearly 100% reaction probability. When H₂ hits other atoms which are by nature much heavier than H₂, mass disparity bars effective energy transfer and this both blocks undesirable bond dissociation and reduces unnecessary energy wastage. The recombination of the carbon radicals generated by the C-H cleavage efficiently completes the production of C-C cross-links at room temperature with no additional energy/chemicals requirements. In addition to these green chemistry merits, this new method is better than other cross-linking techniques which rely on prerequisite reactions to add cross-linkers to the organic molecules or additional reactants and additives. These promising features are validated by several cross-linking trials which demonstrate desirable mechanical, electrical, chemical, and biochemical changes while inducing no undesirable damage of chemical functionalities in the original molecules.