In the crystal structure of the title compound, C21H24F2N2O2, there are two intra­molecular O—H⋯N hydrogen bonds involving the N atoms of the imidazolidine ring and the hy­droxy groups. The crystal studied was a meso compound obtained by the reaction of the aminal (2S,7R,11S,16R)-1,8,10,17-tetra­aza­penta­cyclo­[8.8.1.18,17.02,7.011,16]cosane with 4-fluoro­phenol. The imidazolidine ring has a twisted conformation with a CH—CH—N—CH2 torsion angle of 44.99 (14)° and, surprisingly, the lone pairs of the N atoms are disposed in a syn isomerism, making the title compound an exception to the typical ‘rabbit-ear effect’ in 1,2-diamines. In the crystal, molecules are linked via C—H⋯F hydrogen bonds, forming chains along the c-axis direction. These chains are linked via another C—H⋯F hydrogen bond, forming a three-dimensional network.

In the title compound, C24H25ClN2, the methine, methyl­ene and methyl C atoms of the methyl-substituted imidazolidine ring are disordered over two sets of sites with a refined occupancy ratio of 0.834 (4):0.166 (4). Each disordered ring assumes an envelope conformation with an N atom as the flap. The pendant benzyl rings are oriented equatorially with respect to the imidazolidine ring. The chloro­phenyl ring is inclined to the mean plane of the four planar atoms of the major component of the imidazolidine ring by 76.27 (12)°. The dihedral angles between the chloro­phenyl ring and the two benzyl rings are 55.31 (9) and 57.50 (8)°; the dihedral angle between these latter rings is 71.59 (9)°. In the crystal, mol­ecules are linked by C—H⋯Cl inter­actions and a number of weak C—H⋯π inter­actions, involving all three aromatic rings, forming a three-dimensional structure.

The imidazolidine ring in the title compound, C19H24N2O2, adopts a twist conformation and its mean plane (r.m.s. deviation = 0.19 Å) makes dihedral angles of 72.38 (9) and 71.64 (9)° with the two pendant aromatic rings. The dihedral angle between the phenyl rings is 55.94 (8)°. The mol­ecular structure shows the presence of two intra­molecular O—H⋯N hydrogen bonds between the phenolic hydroxyl groups and N atoms with graph-set motif S(6). In the crystal, C—H⋯O hydrogen bonds lead to the formation of chains along the b-axis direction.

In the title compound, C17H18F2N2O2, the imidazolidine ring system exists in a twist conformation. The mean plane through this ring system forms dihedral angles of 80.8 (8)° and 66.2 (13)°, with the benzene rings. The dihedral angle between the benzene rings is 52.0 (14)°. Two intra­molecular O—H⋯N hydrogen bonds each generate S(6) ring motifs. In the crystal, weak C—H⋯O hydrogen bonds form dimers, which are connected by further C—H⋯O inter­actions.

The title compound, C23H32Cl2N2O2, a potential chiral ligand for coordination chemistry, was prepared by a two-step reaction. The mol­ecule is located on a crystallographic centre of inversion. As a result, the methyl group bonded to the methyl­ene group is disordered over two equally occupied positions, sharing the same site as the H atom of the chiral C atom. As a further consequence of the crystallographic centrosymmetry, the 1,2-diamino­propane unit adopts an anti­periplanar conformation and the two benzene rings are coplanar. The central chain is in an all-trans arrangement. An intra­molecular O—H⋯N hydrogen bond makes an S(6) ring motif. A C—H⋯π inter­action links the mol­ecules into one-dimensional chains along the [001] direction.

The asymmetric unit of the title compound, C20H24N2O4·H2O, contains one half-organic mol­ecule (an inversion centre generates the other half of the mol­ecule) and a half-mol­ecule of water (the O atom has site symmetry 2). The near planarity of the fused-benzene ring is illustrated by the very small deviations of all the atoms from the plane [largest deviation = 0.0092 (11) Å. The six-membered N,O-containing ring adopts a half-chair conformation. The observed N—CH2 and CH2—O bond lengths can be correlated to the manifestation of an anomeric effect in the N—CH2—O unit. In the crystal, the mol­ecules are connected into zigzag chains parallel to [001] through O—H⋯N hydrogen bonds formed between the oxazinic N atom and the solvent water mol­ecule. The chains are consolidated by C—H⋯O inter­actions.

The title compound, C3H6N4O2, exhibits partial disorder with the refined occupancy ratios of the two components being 0.582 (5):0.418 (5). In the major component, the nitroso groups have a relative syn spatial arrangement [O=N⋯N=O pseudo-torsion angle = 1.1 (4)°], whereas the other component has an anti disposition [177.6 (1)°]. The N—N=O moieties are almost coplanar with a dihedral angle of 5.3 (3)°, while in the minor occupied set of atoms, this angle is 8 (1)°. In both components, the imidazolidine ring adopts a twisted conformation on the C—C bond and the crystal structure shows the strain of this ring according to the N—CH2—CH2—N torsion angles [25.9 (5) and −23.8 (7)°]. In the crystal, molecules are linked by weak C—H⋯O hydrogen bonds.

In the title compound, C24H20N4, obtained through the condensation of naphthalene-2,3-diamine with formaldehyde in methanol, the mol­ecule is located on a special position of site symmetry -4. Due to symmetry considerations, the aromatic rings are strictly perpendicular to each other. In the crystal, mol­ecules are linked by pairs of C—H⋯π inter­actions into columns along [110].

In the mol­ecule of the title compound, C20H26N2O2, the 1,3-diazinane ring adopts a slightly distorted chair conformation and the hy­droxy­benzyl substituents occupy equatorial positions on the N atoms of the heterocyclic ring. There are two intra­molecular O—H⋯N hydrogen bonds between the N atoms of the 1,3-diazinane ring and the hy­droxy groups of the aromatic rings, with an S(6) set-graph motif. However, the two observed intra­molecular hydrogen-bond distances were different. Considering that both N atoms experience the same chemical environment, it is surprising to see the difference in O⋯N distances [2.6771 (14) and 2.8123 (12) Å]. The crystal structure is further stabilized by a C—H⋯π interaction.

In the title compound, C8H8N2O, the N—CH2 and CH2—O bond lengths can be correlated to the manifestation of an anomeric effect in the N—CH2—O moiety. In the crystal, inter­molecular O—H⋯N hydrogen bonds link the mol­ecules into zigzag chains, with graph-set motif C(6), parallel to [001]. These chains are further linked into sheets by weak nonclassical C—H⋯O hydrogen bonds.

The title compound, C18H20Br2N2O2, the heterocyclic ring adopts a chair conformation. The benzene rings make dihedral angles of 86.84 (10) and 60.73 (10)° with the mean plane of the heterocyclic ring. The dihedral angle between the two benzene rings is 79.77 (10)°. The mol­ecular structure is stabilized by two intra­molecular hydrogen bonds between the phenolic hy­droxy groups and N atoms with graph-set motif S(6). The crystal structure is stabilized by weak C—H⋯π inter­actions.

In the title compound, C17H18N8, the imidazolidine ring adopts an envelope conformation with the substituents at the N atoms in trans positions with respect to the central ring. The dihedral angle between the two benzotriazole rings is 71.65 (10)°. In the crystal, non-classical C—H⋯N inter­actions link the mol­ecules into helical chains along the b axis. The crystal packing is further stabilized by weak C—H⋯π inter­actions.

The imidazole ring in the title compound, C27H22N8, adopts a slight envelope conformation with the C atom carrying the phenyl ring being the flap atom. The phenyl ring is almost perpendicular to the mean plane of the imidazole ring [dihedral angle = 88.90 (7)°]. The (1H-benzotriazol-1-yl)methyl groups bound to the imidazole ring are positioned on the same side of the imidazole ring. The dihedral angle between these benzotriazolyl rings is 17.71 (5)°. The crystal packing is stabilized by a C—H⋯π inter­action, which connects the mol­ecules into zigzag chains running along the b axis.

In the title hexa­hydro­pyrimidine derivative, C28H42N2O4·0.19H2O, the 1,3-diazinane ring has a chair conformation with a diequatorial substitution. The asymmetric unit contains one half-organic mol­ecule and a solvent water mol­ecule with occupany 0.095. The mol­ecule lies on a mirror plane perpendicular to [010] which passes through the C atoms at the 2- and 5-positions of the heterocyclic system. The partially occupied water mol­ecule is also located on this mirror plane. The dihedral angle between the planes of the aromatic rings is 17.71 (3)°. Two intra­molecular O—H⋯N hydrogen bonds with graph-set motif S(6) are present. No remarkable inter­molecular contacts exist in the crystal structure.

The title compound, C18H20N2O2, was prepared by Mannich-type reaction of phenol, ethane-1,2-diamine and formaldehyde. The heterocyclic rings adopt half-chair conformations. The acyclic methyl­ene groups attached to the N atoms are in an axial position. In the crystal, weak C—H⋯O hydrogen bonds link the mol­ecules into dimers. These dimers are further connected via C—H⋯π contacts.

In the title mol­ecule, C17H20N2O2, the imidazolidine ring adopts a twist conformation. The mean plane through the five atoms of the imidazolidine ring makes dihedral angles of 70.18 (4) and 74.14 (4)° with the planes of the two aromatic rings. The dihedral angle between the benzene rings is 53.11 (5)°. Both phenol –OH groups form intra­molecular hydrogen bonds to the N atoms, with graph-set motif S(6). In the crystal, pairs of O—H⋯O hydrogen bonds link the mol­ecules into dimers with R 4 4(18) ring motifs. The crystal packing is further stabilized by C—H⋯O and weak C—H⋯π inter­actions.

In the title compound, C13H27N4 +·I−, the ethyl­ene bridge is distorted from the ideal D 2d symmetry wherein an N—C—C—N planar bridge, around whose C—C bond the C—N and C—H bonds are exactly eclipsed, is disordered over two sites with equal occupancies. In both disorder components, the hexyl chain adopts an ideal all-trans conformation. In the crystal, adjacent ions are connected by C—H⋯I hydrogen bonds, forming ionic pairs that are further linked into chains along [101] via a second C—H⋯I inter­action.

The cyclo­hexane ring in the title compound, C21H24N8, adopts a chair conformation and the five-membered heterocyclic ring to which it is fused adopts a twist conformation on their common C—C bond. The substituents on the N atoms of the central five-membered heterocycle are arranged trans with respect to the central ring. The terminal benzotriazole rings are oriented at angles of 74.66 (8) and 84.18 (8)° with respect to the mean plane of the central heterocycle. The angle between the two benzotriazole rings is 30.80 (9)°. The bond lengths and angles are within normal ranges; the largest deviation from expecta­tion is for a long N—CH2 bond length [1.476 (2) Å] as a consequence of an anomeric effect. In the crystal, mol­ecules are connected by C—H⋯N hydrogen bonds.

The title compound, C25H30N2O6, has the imidazolidine ring in an envelope conformation. There are two intra­molecular O—H⋯N hydrogen-bond inter­actions with graph-set motif S(6). The cyclo­hexane ring adopts a slightly distorted chair conformation. One methyl carboxyl­ate substituent forms a dihedral angle of 12.00 (5)° with the plane of the benzene ring, while the other methyl carboxyl­ate group is almost coplanar, making a dihedral angle of 2.26 (9)°. In the crystal, pairs of inter­molecular C—H⋯O hydrogen bonds form racemic dimers, corresponding to an R 2 2(18) graph-set motif. Further weak C—H⋯O inter­actions generate a chain running along the c axis.

In the title compound, C29H42N2O2, the heterocyclic ring has a twist conformation. The cyclohexane ring adopts a chair conformation. The dihedral angle between the aromatic rings is 32.74 (6)°. The mol­ecular conformation is stabilized by two intramolecular O—H⋯N hydrogen bonds with graph-set motif S(6). The crystal packing is stabilized by C—H⋯O and C—H⋯π inter­actions.

The heterocyclic ring in the title compound, C27H34N2O6, has an envelope conformation on one of the bridgehead C atoms [Q(2) = 0.4487 (19) Å and ϕ = 291.3 (2)°]. Two strong intra­molecular O—H⋯N hydrogen bonds stabilize the mol­ecular conformation. The benzoate groups differ in the relative orientations of the ethyl groups, as quanti­fied by the values of the C—O—C—C torsion angles of −86.5 (2) and −178.97 (17)°. The carbonyl groups are nearly coplanar with the benzene rings, forming C—C—C—O torsion angles of 0.9 (3) and 3.4 (3)°. The crystal structure is stabilized by weak inter­molecular C—H⋯O inter­actions.

A new monoclinic polymorph of the title compound, C8H12N4, in the space group P21/n (Z = 4) is reported. The previously known form was also monoclinic, P21 /c (Z = 4), but the unit-cell parameters and crystal packing were different [Shoja & Saba (1993 ▶). Acta Cryst. C49, 354–355]. The hexa­hydro­pyrimidine ring of the title compound adopts a chair conformation with a diequatorial substitution and with the CH2-C N groups oriented nearly parallel and in the same direction [NC—CH2⋯CH2—CN pseudo torsion angle = −6.27 (18)°]. In the crystal, inter­molecular C—H⋯ N hydrogen bonds connects the mol­ecules into a chain along the b axis.

Background

Novel mono N-alkyl quaternary ammonium salts (3a-f) were prepared using the Menschutkin reaction from the cage adamanzane type aminal 1,3,6,8-tetraazatricyclo[4.3.1.13,8]undecane (TATU) and alkyl iodides, such as methyl, ethyl, propyl, butyl, pentyl and hexyl iodide (2a-f), in dry acetonitrile at room temperature.

Results

The structures of these new quaternary ammonium salts were established using various spectral and electrospray ionization mass spectrometry (ESI-MS) analyses. Compound (3b) was also analyzed using X-ray crystallography.

Conclusion

It was noted that alkyl chain length did not significantly affect the reaction because all employed alkyl iodide electrophiles reacted in a similar fashion with the aminal 1 to produce the corresponding mono N-quaternary ammonium salts, which were characterized by spectroscopic and analytical techniques.

The title compound C14H29N4 +·I− salt, was obtained by the reaction of cage adamanzane-type aminal 1,3,6,8-tetra­aza­tricyclo­[4.3.1.13,8]undecane with heptyl iodide. In the cation, the bond lengths and angles are within normal ranges, except for one N—C(ring) bond distance of 1.542 (3) Å, which is unexpectedly long compared with related compounds. In the crystal, ions are linked through C—H⋯I hydrogen bonds. The crystal studied was a non-merohedral twin with a minor twin domain of 6.56 (5)%.

The title compound, C29H38N2O6, was prepared as model for studying intra­molecular hydrogen-bonding inter­actions. Mol­ecules of the title compound are located on a crystallographic twofold rotation axis, which passes through the C atom linked to the two N atoms on the imidazolidine ring. The mol­ecular structure shows the existence of two intra­molecular O—H⋯N hydrogen-bonding inter­actions between the two N atoms of the imidazolidine moiety and the hy­droxy groups in the aromatic rings. The crystal structure shows the strain of ring fusion in the perhydro­benzimidazole moiety according to the endocyclic bond angles and the torsion angles, which evidence a puckering of the cyclo­hexane ring with respect to normal tetra­hedral bond angles in an ideal chair conformation.