Preferential N–H⋯:C hydrogen bonding involving ditopic NH-containing systems and N-heterocyclic carbenes

Abstract

Non-traditional hydrogen bonds between a singlet carbene and a series of ditopic secondary amines is detailed. Both the solid- and solution-state metrics reveal the strength of these associations are dependent on the pKa of the NH-containing molecule.

On the Coexistence of the Carbene⋯H-D Hydrogen Bond and Other Accompanying Interactions in Forty Dimers of N-Heterocyclic-Carbenes (I, IMe2, IiPr2, ItBu2, IMes2, IDipp2, IAd2; I = imidazol-2-ylidene) and Some Fundamental Proton Donors (HF, HCN, H2O, MeOH, NH3)

“…There are two C⋯H-C type hydrogen bonds in the crystal form of 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene (GUXJAK02) [ 118 ]. Both the dimer between 1,3-dimesityl-imidazol-2-ylidene and diphenylamine (MODVEG) [ 119 ] and between 1,3-bis[2,6- diisopropylphenyl]imidazol-2-ylidene and N ,N -diphenylbenzene-1,4-diamine (LAGYEB) [ 120 ] have one C⋯H-N hydrogen bond, while the dimer of N-methyl-2-(3-phenyl-2,3-dihydro-1H-imidazol-1-yl)ethanamine (AWIBOY) [ 121 ] has two. 1,3-dimesitylimidazol-2-ylidene in methanol (JAPDEK) [ 122 ], on the other hand, is the simplest example of the occurrence of a C⋯H-O type hydrogen bond and was reported as the first X-ray structure of a carbene–alkohol hydrogen-bonded complex.…”

Halogen bonding regulated functional nanomaterials

“…Intermolecular noncovalent interactions bear an immense technological potential owing to their versatile capability of construction of various complex supramolecular architectures which have found application in drug delivery, [1][2][3] materials engineering, 4,5 catalysis, 6,7 sensors, 6,[8][9][10] biological chemistry, [11][12][13] and many others. [14][15][16] Some prominent noncovalent interactions includes hydrogen bonding (HB), [17][18][19][20][21][22] halogen bonding (XB), 23,24 π-π interaction, [25][26][27] metal ion coordination, [28][29][30][31] hydrophobic interaction, [32][33][34][35] donor-acceptor interaction, [36][37][38] and so on.…”

Mechanistic insights and comparative analysis of Ru(ii)–NNC pincer complexes with anionic-, protic-, and classical-NHCs for transfer hydrogenation of ketones

“…[12][13][14][15][16][17][18][19][20] The pNHCs have attracted significant attention over the classical NHCs due to the existence of a proton-responsive NH group, allowing H-bonding interactions, β-deprotonations, and nucleophilic additions. [21][22][23][24][25] Kuwata and Ikariya reported that a pNHC Ru complex catalyzes the dehydrative coupling of an N-heterocycle with allyl alcohol. 26 Grotjahn and coworkers revealed that Rh and Ir complexes with pNHC ligands were effective catalysts for the transfer hydrogenation (TH) of acetophenone and chalcone.…”