Cyclohexanecarboxamide

Abstract

The title compound, C(7)H(13)NO, forms R(2)(2)(8) N-H...O hydrogen-bonded dimers and C4 N-H...O-linked chains, which are further stabilized by a C-H...O interaction. The combination of these interactions results in a hydrogen-bonded network parallel to (100), with a motif that can be described by the secondary graph set R(4)(6)(16). The existence of the same hydrogen-bonding motif in 1-phenylcyclopentanecarboxamide and 1-(2-bromophenyl)cyclohexanecarboxamide [Lemmerer & Michael (2008). CrystEngComm, 10, 95-102 indicates that replacing the H atom on position 1 with a more bulky group does not necessarily disrupt the observed hydrogen-bonding pattern. The presence of a C-H...O interaction to stabilize the R(4)(6)(16) network does, however, seem to be required. In addition, the title compound is isomorphous with a previously published structure of cyclopentanecarboxamide [Winter et al. (1981). Acta Cryst. B37, 2183-2185].

Role of weak C—H...O and strong N—H...O intermolecular interactions on the high-symmetry molecular packing of trans-cyclohexane-1,4-dicarboxamide

“…3b), the IMCs are also connected by C-H eq Á Á ÁO contacts between H atoms equatorially (eq) bonded to unsubstituted ring C atoms and carbonyl O atoms. Similar weak C-HÁ Á ÁO hydrogen-bond interactions have been observed previously in monosubstituted cyclohexanecarboxamide by Zipp et al (2009) and in cubane-1,4-dicarboxamide, 2, by Kuduva et al (2001). It should be noted that in all the mentioned C-HÁ Á ÁO contacts, the H atom bonded to an unsubstituted C atom approaches to the carbonyl O atoms nearly perpendicular to the R 2 2 (8) cyclic dimer plane (for details, see Table 2), pointing to the (C O) bond, instead of the expected approach to the sp 2 O-atom lone pairs.…”