Computational studies of nanoscale environments for selective reactivity in a supported iridium cluster catalyst

The active sites of enzymes are typically within nanoscale environments that tend to be specific to particular mols. Creating similar nanoscale environments on synthetic surfaces that are capable of selective reactivity would be useful in processes such as gas sepn. and nanosensing. Although, developing a complex with these desirable properties is essential, there is still a significant challenge. D. functional theory was used to study a tetrairidium cluster with three calixarene phosphine and carbonyl ligands in order to create a selective nanoscale environment and elucidate exptl. results. The aim of the study was to gain a better understanding of the mechanism of decarbonylation and subsequent ethylene activation. The ONIOM quantum mechanics /mol. mechanics (QM/MM) method was used for the calcn. due to the size of the ligands. Results confirm exptl. observation of site specific decarbonylation and ethylene binding. The calcns. also provide an insight into criteria for selective catalysis.