Phosphonium ylides as hydrogen bond acceptors: intermolecular C–H⋯C interactions in the crystal structure of triphenylphosphonium benzylide

Abstract

A pairwise alignment of molecules in the crystal structure of the title ylide suggests the existence of mutual C-H-*C interactions between acidic o-Ph groups of one molecule and the basic carbanionoid centre of the other, an interpretation which is supported by examination of previously reported X-ray data.

Steric and Electronic Influence on the Coordination Aptitude of 4-Formylpiperazine-1-Carbodithioate Towards Triorganotin(IV) Moieties

“…b). Interestingly, the saltire‐shaped arrangement is further stabilized by unconventional CH···C interactions [C(4)–H(4)···C(5) 2.821 Å] . A relatively acidic C(4)–H(4) bond forms a weaker hydrogen bond with C(4) of the upper saltire‐shaped polymeric chain.…”

6a,6b,12a,12b-Tetrahydrocycloocta[3,4]cyclobuta[1,2][8]annulene

“…In addition, the role of CÐHÁ Á Á% interactions in crystal packing has also been recognized through several examples wherein the solid-state architecture is determined by a network of weak hydrogen bonds involving alkene, alkyne and aromatic %-bonds as acceptors. However, most of the systems studied so far have been multifunctional, in which there could be some in¯uence of other intermolecular forces, besides the CÐHÁ Á Á% interactions, in determining the three-dimensional molecular packing (Steiner, 1995;Steiner et al, 1995;Platts et al, 1996;Batsanov et al, 1996;Madhavi et al, 1997;Lutz et al, 1998;Harder, 1999;Takahashi et al, 2001). Thus, the crystal structures of pure hydrocarbons can be more illuminating in delineating the interplay of weak CÐHÁ Á Á% interactions in crystal packing.…”

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

“…15 Most oen these non-traditional species are mediated via formally charged carbon centers (such as isonitriles and carbanions) as the hydrogen bond acceptor. 16,17 Since the rst isolation of singlet carbenes their proliferation to all corners of chemistry are readily apparent. [18][19][20][21][22] Though a variety of singlet carbenes are now synthetically accessible, 23,24 N-heterocyclic carbenes (NHCs) based on an imidazole core remain one of the most well-studied and utilized class of carbenes.…”