Non-covalent interactions involving remote substituents influence the topologies of supramolecular chains featuring hydroxyl-O–H⋯O(hydroxyl) hydrogen bonding in crystals of (HOCH2CH2)2NC(S)N(H)(C6H4Y-4) for Y = H, Me, Cl and NO2

Secondary non-covalent interactions prove crucial in determining the topology of supramolecular chains sustained by conventional O–H⋯O hydrogen bonding.

Metal-dependent photochromic performance in two isostructural supramolecular chains

The introduction of nonphotochromic coplanar 1,10-phenanthroline into a metal carboxylate system produces two isostructural supramolecular chains with metal-dependent photochromic performance.

Ethyl 3,4-bis(acetyloxy)-2-(4-methoxyphenyl)pyrrolidine-1-carboxylate

The title pyrrolidine compound, C18H23NO7, is a tetra-substituted species in which the five-membered ring has a twisted conformation with the twist occurring in the C—C bond bearing the adjacent acetyloxy substituents; the Cm—Ca—Ca—Cp torsion angle is −40.76 (18)° [m = methylene, a = acetyloxy and p = phenyl]. The N atom, which is sp 2-hybridized [sum of bond angles = 359.4°], bears an ethylcarboxylate substitutent and is connected to a methylene-C atom on one side and a carbon atom bearing a 4-methoxyphenyl group on the other side. Minor disorder is noted in the ethylcarboxylate substituent as well as in one of the acetyloxy groups; the major components of the disorder have site occupancies of 0.729 (9) and 0.62 (3), respectively. The most notable feature of the molecular packing is the formation of helical, supramolecular chains aligned along the b-axis direction whereby the carbonyl-O atom not involved in a disordered residue accepts C—H...O interactions from methylene-H and two-C atom separated methine-H atoms to form a six-membered {...HCCCH...O} synthon.

Diethyl 3,3′-[(3-fluorophenyl)methylene]bis(1H-indole-2-carboxylate)

In the title compound, C29H25FN2O4, the mean planes of the indole ring systems are approximately perpendicular to one another [dihedral angle = 88.3 (4)°]. The benzene ring is twisted with respect to the indole ring systems by 49.8 (5) and 77.6 (3)°. In the crystal, pairs of N—H...O hydrogen bonds link the molecules into the inversion dimers which are further linked into supramolecular chains propagating along the [110] direction.

Crystal structures of two dis-symmetric di-Schiff base compounds: 2-({(E)-2-[(E)-2,6-dichlorobenzylidene]hydrazin-1-ylidene}methyl)-6-methoxyphenol and 4-bromo-2-({(E)-2-[(E)-2,6-dichlorobenzylidene]hydrazin-1-ylidene}methyl)phenol

Each of the title dis-symmetric di-Schiff base compounds, C15H12Cl2N2O2 (I) and C14H9BrCl2N2O (II), features a central azo-N—N bond connecting two imine groups, each with an E-configuration. One imine bond in each molecule connects to a 2,6-dichlorobenzene substituent while the other links a 2-hydroxyl-3-methoxy-substituted benzene ring in (I) or a 2-hydroxyl-4-bromo benzene ring in (II). Each molecule features an intramolecular hydroxyl-O—H...N(imine) hydrogen bond. The C—N—N—C torsion angles of −151.0 (3)° for (I) and 177.8 (6)° (II) indicates a significant twist in the former. The common feature of the molecular packing is the formation of supramolecular chains. In (I), the linear chains are aligned along the a-axis direction and the molecules are linked by methoxy-C—H...O(methoxy) and chlorobenzene-C—Cl...π(chlorobenzene) interactions. The chain in (II) is also aligned along the a axis but, has a zigzag topology and is sustained by Br...O [3.132 (4) Å] secondary bonding interactions. In each crystal, the chains pack without directional interactions between them. The non-covalent interactions are delineated in the study of the calculated Hirshfeld surfaces. Dispersion forces make the most significant contributions to the identified intermolecular interactions in each of (I) and (II).

Novel Coordination Polymer of Cadmium (II) with L-Tryptophan

A new cadmium (II) polymeric coordination compound with tryptophan (Trp) of general formula {[Cd(L-Trp)2(H2O)Cl]∙(Trp)∙(H2O)}n was synthesized. The monocrystals of the investigated complex were obtained using the method of slow evaporation. The crystal and molecular structure was determined. The compound was crystallized in the orthorhombic P212121 space group. The cadmium atom was seven coordinates by two oxygen atoms from one bidentate-chelating carboxylate group of bridging Trp, two oxygen atoms from one bidentate-chelating carboxylate group from a monodentate organic ligand, one oxygen atom of water molecule, one nitrogen atom of the amino group from bridging Trp and one chlorine atom, which means that every tridentate Trp substituent was bridging towards one cadmium atom and bidentate chelating towards one another. The monodentate Trp is a zwitterionic molecule. The coordination led to the formation of 1D supramolecular chains entrapping water and Trp molecules.