LAUSR

Abstract Iridium complexes have been widely applied to energy and chemical industry, pharmaceutical industry, and organic synthesis. As a parameter reflecting the interaction between ligands and metal centers, trans-effect plays an important role in the kinetics/thermodynamic stability, the reactivity and the catalytic performance of transition metal complexes. A systematic study was conducted herein to address the abnormal trans-effect of iridium halide complexes reported by Werneke et al. It is found that the observed unconventional trans-effect mainly results from the different cis-to-trans isomerization energies of different tetra-coordinated iridium complexes. The relevant results provide deeper insights into understanding the trans-effect based on the experimentally measured bond dissociation energies, and thus benefit the design and development of new, highly effective hydrogen fuel carrier metal complexes.