N-heterocyclic carbenes are most accessible organic ligands in both organometallic and coordination chemistry, which is reflected by thousands of applications involving NHC-bearing metal complexes in areas ranging from homogeneous catalysis to material science [1]. The chemistry of N-heterocyclic carbenes (NHCs) and their metal complexes has advanced significantly over the last two decades in the field of organometallic catalysis and medicinal chemistry [2]. Herein we want to report a theoretical study on structure and nature of C→Re bonds in some derivatives of [(NHC(R))4Re(N)(Y)] (Y= F, Cl, Br R=H, CH3, F, Cl, Br) complexes at PBE1PBE/def2-SVP level of theory.
