Cationic ruthenium(II)-NHC pincer complexes with hemilabile COD: Solid-state structural characterization and theoretical study of an η2-(E,Z)-COD ligand

Base-free synthesis of benchtop stable Ru(iii)–NHC complexes from RuCl3·3H2O and their use as precursors for Ru(ii)–NHC complexes

“…We have recently started the investigation of Ru( ii )–CNC (CNC = pyridine-dicarbene pincer ligands) complexes with smaller N -alkyl wingtips on carbenes for transfer hydrogenation and related catalysis 38–40 and compared their activity with that of molecular catalysts with similar catalyst design. 7 During our investigation, we noticed that even after a few decades of research in this field, a suitable Ru complex with an NHC ligand, which can be used as a precursor for the synthesis of new complexes with other co-ligands, is unavailable.…”

“…23 Among the various synthetic routes reported for the generation of NHCs and their corresponding metal complexes, namely, baseassisted deprotonation of azolium salts followed by metalation, transmetallation of preformed Ag(I)/Cu(I) carbenes, and C-H activation of azolium salts in the presence of metal precursors, C-H activation is considered as one of the simplest routes for the generation of carbene due to the less probability of formation of side product. 36,37 We have recently started the investigation of Ru(II)-CNC (CNC = pyridine-dicarbene pincer ligands) complexes with smaller N-alkyl wingtips on carbenes for transfer hydrogenation and related catalysis, [38][39][40] and compared their activity with the molecular catalysts with similar catalyst design. 7 During our investigation, we noticed that even after a few decades of research in this field, a suitable Ru complex with an NHC ligand, which can be used as a precursor for the synthesis of new complexes with other co-ligands, is still unavailable.…”

Role of ancillary ligands in selectivity towards acceptorless dehydrogenation versus dehydrogenative coupling of alcohols and amines catalyzed by cationic ruthenium(ii)–CNC pincer complexes

“…1). [70][71][72] The smaller N-alkyl wingtips allow the preparation of complexes with a variety of co-ligands and have enabled the observation of their effect on the catalytic performance. Furthermore, the hydride complex 4a was synthesized from 3a and confirmed to be the active catalyst formed during catalysis with the pre-catalyst 3a.…”

Base-free synthesis of air- and moisture-stable Ru(III)-NHC complexes, [RuIII(PyNHCR)(Cl)3(H2O)] as precursors for Ru(II)-NHC complexes

“…14 These Ru-NHC complexes have found applications in homogeneous organic transformations, 15,16 olefin metathesis reactions, therapeutic drugs, 10 as well as applications in dye-sensitised solar cells (DSSCs). 17 We have recently started exploring the catalytic applications of Ru(II)-CNC (CNC = pyridine-dicarbene pincer ligands) complexes with smaller N-alkyl wingtips on carbenes [18][19][20] . During our investigation, we have noticed that even after a few decades of research in this field, there is no Ru metal precursor with an NHC ligand already present.…”

“…The structures exhibited a pseudooctahedral geometry around the Ru(III) center. The bidentate ligand formed a five membered metallacycle with a bite angle of 79.7( 7) o and 78.34 (19) o in 1a and 1b respectively. In both the structures, the coordinated H2O ligand was replaced by solvent of crystallisation i.e., MeCN in 1a and MeOH in 1b.…”