Large protein macromolecules in enzymatic catalysis have been shown to exert a specific electric field that reduces the reorganization energy upon barrier crossing and thus reduces the reaction free energy barrier. In this work we suggest that the charge density in the active site of an enzyme investigated using formalisms embodied by the quantum theory of atoms in molecules (QTAIM) provides a sensitive and quantum field-reactant state charge density-reaction barrier correlation. Hence, QTAIM can be used for the analysis of electric field in enzyme active sites, and further investigations and exploitations of the found correlations may prove useful in enzyme design where preorganization is optimized.

The abundant yet widely distributed methane resources require efficient conversion of methane into liquid chemicals, whereas an ambient selective process with minimal infrastructure support remains to be demonstrated. Here we report selective electrochemical oxidation of CH 4 to methyl bisulfate (CH 3 OSO 3 H) at ambient pressure and room temperature with a molecular catalyst of vanadium (V)-oxo dimer. This water-tolerant, earthabundant catalyst possesses a low activation energy (10.8 kcal mol-1) and a high turnover frequency (483 and 1336 hr −1 at 1-bar and 3-bar pure CH 4 , respectively). The catalytic system electrochemically converts natural gas mixture into liquid products under ambient conditions over 240 h with a Faradaic efficiency of 90% and turnover numbers exceeding 100,000. This tentatively proposed mechanism is applicable to other d 0 early transition metal species and represents a new scalable approach that helps mitigate the flaring or direct emission of natural gas at remote locations.

Experimental and computational study quantifying internal electric fields in synthetic systems using transition metal Schiff base complexes functionalized with a crown ether unit containing a mono- or dicationic alkali or alkaline earth metal ion.