N-heterocyclic carbene adsorption states on Pt(111) and Ru(0001)

Abstract

N-heterocyclic carbene ligands (NHCs) are increasingly used to tune the properties of metal surfaces. The generally greater chemical and thermal robustness of NHCs on gold, as compared to thiolate surface...

Vibrational Mode Assignment of Diisopropyl Benzimidazolium N-Heterocyclic Carbenes on Gold

“…14 Consequently, there are many works focusing on the spectroscopic characterization of NHCs including benzimidazolium salts, 15,16 imidazolium salts, 17 free carbene moieties, 18 and CO 2 adducts. 19 Vibrational spectroscopies such as high-resolution electron energy loss spectroscopy (HREELS), 11,20 surface-enhanced Raman spectroscopy (SERS), 21,22 and reflection absorption infrared (IR) spectroscopy (RAIRS) 23,24 have been applied as a tool to study NHC SAMs. They are often used to monitor monolayer formation and stability, 24,25 surface chemical reactions, 26,27 and catalysis.…”

“…19 Vibrational spectroscopies such as high-resolution electron energy loss spectroscopy (HREELS), 11,20 surface-enhanced Raman spectroscopy (SERS), 21,22 and reflection absorption infrared (IR) spectroscopy (RAIRS) 23,24 have been applied as a tool to study NHC SAMs. They are often used to monitor monolayer formation and stability, 24,25 surface chemical reactions, 26,27 and catalysis. 28,29 While previous studies have reported on a subset of the imidazolium and benzimidazolium NHC vibrational modes, 11,30 a systematic and rigorous vibrational mode analysis of NHCs bound to gold is missing in the literature.…”

“…Table S1 provides a comprehensive view of previous studies reporting on vibrational modes of NHCs bound to various flat metal surfaces, with descriptions of the modes assigned by the authors. 11,20,23,24 This survey is the starting point for the current study, although it is necessary to realize that detailed normal mode coordinates are not always reported in these previous studies. Prior work by our group using SERS to study NHCs on gold nanoparticles has focused specifically on normal modes with Au−C character.…”