Karaca, E. O.Akkoc, M.Oz, E.Altin, S.Dorcet, V.Roisnel, T.Gurbuz, N.2024-08-042024-08-0420170095-89721029-0389https://doi.org/10.1080/00958972.2017.1287906https://hdl.handle.net/11616/97701A new series of ring-expanded six-and seven-membered N-heterocyclic carbene precursors (re-NHCs) and their transition metal complexes were synthesized. The basic properties of the synthesized materials were investigated by density functional theory (DFT). The six- and seven-membered re-NHCs were synthesized in good yield via reaction of the corresponding alkyldibromides or alkyldiiodides with N,N'-bis-(2-phenylbenzene)formamidine in the presence of K2CO3 under aerobic conditions. Complexes, represented by the formula [ML1,2(COD)Cl] (where M = Ir or Rh and L is a ring-expanded N-heterocyclic carbene ligand), were synthesized in the presence of the corresponding free carbene and iridium or rhodium metal precursors in tetrahydrofuran. All new re-NHC complexes were characterized by different analytical techniques, including NMR spectroscopy, X-ray diffraction, UV spectroscopy and elemental analysis. According to molecular electrostatic potential calculations, the electrophilic properties of the complexes were aligned, from highest to lowest, as Ir-6-DiPh, Rh-6-DiPh and Ir-7-DiPh. The HOMO, LUMO and energy gaps of the complexes were calculated by DFT. On the basis of the DFT analysis, it can be predicted that Rh-6-DiPh is the most stable complex and Ir-7-DiPh is more reactive than Ir-6-DiPh. [GRAPHICS] .eninfo:eu-repo/semantics/closedAccessIridiumrhodiumN-Heterocyclic carbeneDFT calculationX-rayArticle7071270128410.1080/00958972.2017.12879062-s2.0-85013486029Q3WOS:000398290200012Q3