In the title compound, C17H12N2O3, the mean planes of the benzene ring and the quinoline moiety are inclined to one another by 11.0 (1)°. The nitro substituent is twisted at an angle of 7.9 (2)° with respect to the attached benzene ring. Intra-molecular O-H⋯N and C-H⋯N hydrogen bonds occur. The crystal is constructed of mol-ecular stacks without involvement of π-stacking inter-actions, but show...

In the title salt, C(10)H(10)N(3) (+)·ClO(4) (-), the 4-(4-pyridylamino)-pyridinium cations are linked into chains via N-H⋯N hydrogen bonding and into layers by C-H⋯π inter-actions [C⋯Cg = 3.3875 (19) Å]. Perchlorate ions are anchored to the layer motifs by N-H⋯O hydrogen bonding. The perchlorate anion was found to be disordered about a Cl-O axis, with two sites, each of equal occupancy, being ...

We address the broader conceptual and pedagogical implications of recent recommendations of the International Union of Pure and Applied Chemistry (IUPAC) concerning the re-definition of hydrogen bonding, drawing upon the recommended IUPAC statistical methodology of mutually correlated experimental and theoretical descriptors to operationally address the title question. Both direct and statistic...

In the title compound, {(C(16)H(22)N(4))[Co(C(10)H(2)O(8))(H(2)O)(4)]·2H(2)O}(n), the octa-hedrally coordinated Co(II) atom is situated on an inversion center and possesses four aqua ligands. The Co atoms are linked into an anionic coordination polymer chain by bis-monodentate pyromellitate ligands. The chain motifs are connected into a supra-molecular layer by hydrogen bonding mediated by unco...

In the title compound, C(15)H(13)N(3)O(4), the pyridine and benzene rings are nearly perpendicular [dihedral angle = 84.24 (5)°]. In the crystal structure, classical O-H⋯N hydrogen bonding between the OH group of the carboxyl unit and a neighbouring pyridine ring N atom and N-H⋯O hydrogen bonding between the imine NH group and a neighbouring O atom of an acyl unit, together with complementary n...

The asymmetric unit of the title compound, {(C(4)H(7)N(2))[CdCl(3)(H(2)O)]}(n), contains one 1-methyl-1H-imidazol-3-ium cation, one Cd(II) atom, three Cl atoms and one water mol-ecule. Adjacent Cd ions are inter-connected alternately by paired Cl(-) bridges to generate an infinite one-dimensional coordination chain along the b axis. In the chain, the crystallographically unique Cd(II) atom, wit...

In the title compound, C(19)H(36)N(3) (+)·I(-), the orientation of the cyclo-hexyl 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 tricyclo-hexyl-guanidinium cation (hereafter denoted CHGH(+)), hydrogen bonding is restricted to classical N-H⋯I and non-clasical (cyclo-hex-y...

The crystal structure of the title compound, C(12)H(22)N(+)·Cl(-)·0.1H(2)O, consists of (3,5-dimethyl-1-adamantyl)ammonium chloride (memanti-nium chloride) and uncoordinated water mol-ecules. The four six-membered rings of the memanti-nium cation assume typical chair conformations. The Cl(-) counter-anion links with the memanti-nium cation via N-H⋯Cl hydrogen bonding, forming channels where the...

The asymmetric unit of the crystal structure of the title complex, [Ni(C(18)H(12)N(2)O(3))(C(5)H(5)N)(3)]·3C(5)H(5)N, contains two independent Ni(II) complex mol-ecules and six uncoordinated pyridine mol-ecules. Each Ni(II) atom is coordinated by two O and four N atoms, from three pyridine and a chelating 3-hydr-oxy-N'-(2-oxidobenzyl-idene)-2-naphthohydrazide dianionic ligand, with a distorted ...