N,N′,N′′-Tricyclohexylguanidinium iodide

In the title compound, C19H36N3 +·I−, the orientation of the cyclohexyl rings around the planar (sum of N—C—N angles = 360°) CN3 + unit produces steric hindrance around the N—H groups. As a consequence of this particular orientation of the tricyclohexylguanidinium cation (hereafter denoted CHGH+), hydrogen bonding is restricted to classical N—H⋯I and non-clasical (cyclohexyl)C—H⋯I hydrogen bonds. The propeller CHGH+ cation and the oriented hydrogen-bonding interactions lead to a three-dimensional supramolecular structure.

In the title compound, C 19 H 36 N 3 + ÁI À , the orientation of the cyclohexyl rings around the planar (sum of N-C-N angles = 360 ) CN 3 + unit produces steric hindrance around the N-H groups. As a consequence of this particular orientation of the tricyclohexylguanidinium cation (hereafter denoted CHGH + ), hydrogen bonding is restricted to classical N-HÁ Á ÁI and nonclasical (cyclohexyl)C-HÁ Á ÁI hydrogen bonds. The propeller CHGH + cation and the oriented hydrogen-bonding interactions lead to a three-dimensional supramolecular structure.

Comment
Guanidines are of special interest due to their possible application in medicine (Yoshiizumi et al., 1998;Moroni et al., 2001).
They are considered super bases as they are easily protonated to generate guanidinium cations (Ishikawa & Isobe, 2002).
The structural features and hydrogen bonding array provided by these cations suggest that they are good building blocks for the formation of supramolecular entities , Said et al., 2005.
The title compound (I), Fig. 1, is a typical N,N',N"-trisubstituted guanidinium halide salt with normal geometric parameters (Said et al., 2005). The central guanidinium fragment of the cation of the title salt is planar [sum of NCN angles is 360°] with bond lengths and angles as expected for a central Csp 2 hybridization, accounting for charge delocalization between the three C-N bonds. The bond length C1-N1 [1.330 (5) Å] is comparable with literature averages for substituted and unsubstituted guanidinium cations (1.321 and 1.328 Å, respectively; (Allen et al., 1987)). The cyclohexyl ring has the normal chair conformation with conventional bond lengths and angles. A partial packing diagram is shown in immediately of the solution (0.46 g, 92.0% yield). The product was crystallized from a mixture of methanol and distilled water to give white cubic crystals. In addition to confirming the molecular formula through elemental analysis, the solid obtained was examined by single-crystal X-ray analysis. Anal. Calcd for C 19 H 36 IN 3 C,52.65;H,8.37;N,9.70. Found C,52.56;H,8.63;N,9.40. supplementary materials sup-2 Refinement Hydrogen atoms were included in calculated positions and refined as riding on their parent atoms with C-H = 0.97 Å and U iso (H) = 1.2U eq (C) and N-H = 0.86 Å and U iso (H) = 1.2U eq (N). Fig. 1. The structure of (I) with the guanidinium cation symmetry unique atoms are labeled. The other atoms are related by threefold rotation (3/2 -z, 1 -x, 1/2 + y and 1 -y, -1/2 + y, 3/ 2 -x).