Synthesis and crystal structures of the potential tyrosinase inhibitors N-(4-acetyl­phen­yl)-2-chloro­acetamide and 2-(4-acetyl­anilino)-2-oxo­ethyl cinnamate

Substituted benzoic acid and cinnamic acid esters are of inter­est as tyrosinase inhibitors. In the amide-based intermediate N-(4-acetyl­phen­yl)-2-chloro­acetamide, the acetyl­phenyl ring and the N—(C=O)—C unit of the acetamide group are almost coplanar. Instead of esterification, a cheaper and more efficient synthetic method has been developed for the preparation of 2-(4-acetyl­anilino)-2-oxoethyl cinnamate, in which the acetamide and cinnamate groups are also almost planar. N—H⋯O, C—H⋯O and C—H⋯π inter­actions link mol­ecules of both compounds into three-dimensional networks.

Assembly of Zn^II and Cd^II coordination polymers based on a flexible multi­carboxyl­ate ligand and nitrogen-containing auxiliary ligands through a mixed-ligand synthetic strategy: syntheses, structures and fluorescence properties

Two d¹⁰ coordination polymers of Zn^II and Cd^II have been synthesized from a flexible 4,4′-(1,4-phenylenedioxy)bis(benzene-1,2-dicarboxylate) ligand and two different N-containing auxiliary ligands through a mixed-ligand synthetic strategy under a solvothermal environment. Both compounds present one-dimensional chain structures and two-dimensional supramolecular layer structures constructed through weak hydrogen bonds.

Cyclic hetero­tetra­meric and low-dimensional hydrogen-bonded polymeric structures in the morpholinium salts of ring-substituted benzoic acid analogues

The anhydrous morpholinium salts of the ring-substituted benzoic acid analogues salicylic acid, 3,5-di­nitro­salicylic acid, 3,5-di­nitro­benzoic acid and 4-nitro­anthranilic acid provide two examples of one-dimensional hydrogen-bonded chain polymers, one of a two-layered ribbon structure and one of a discrete cyclic hydrogen-bonded hetero­tetra­mer.

Reaction-path calculations and crystal structures of 1,1′-(ethyl­ene-1,2-di­yl)dipyridinium dichloride dihydrate and 1,1′-(ethyl­ene-1,2-di­yl)dipyridinium dibromide

Reaction pathway calculations reveal that 1,1′-(ethyl­ene-1,2-di­yl)dipyridinium dichloride dihydrate and 1,1′-(ethyl­ene-1,2-di­yl)dipyridinium dibromide, whose structures were determined by powder X-ray diffraction, are formed by successive S_N2 reactions beginning with pyridine and the appropriate 1,2-dihalo­ethane.

Syntheses and structures of discrete copper(II) and cadmium(II) supra­molecular complexes based on 1,4-di­acyl­thio­semicarbazone ligands

Discrete binuclear copper(II) and tetranuclear cad­mium(II) complexes containing deprotonated N-[2-(2-hy­droxy­benzo­yl)hydrazinecarbono­thio­yl]propanamide ligands are connected by hydrogen bonds and van der Waals inter­actions to form three-dimensional supra­molecular architectures. The different coordination modes may be attributed to the larger ionic radius of the Cd^II ion compared with the Cu^II ion.

Nobiletin: a citrus flavonoid displaying potent physiological activity

Based on its potent physiological activities, the citrus flavonoid nobiletin has become an attractive candidate for use as a therapeutic agent. The crystal structure analysis revealed it to be conformationally chiral because of the conformational arrangement of the four meth­oxy groups bound to the chromene ring of the flavone moiety.

A threefold inter­penetrated two-dimensional zinc(II) supra­molecular architecture based on 3-nitro­benzoic acid and 4,4′-bi­pyridine

Zn^II ions are connected by 4,4′-bi­pyridine ligands to form a one-dimensional zigzag chain and the chains are decorated with anionic 3-nitro­benzoate ligands which inter­act further through aromatic π–π stacking inter­actions, expanding the structure into a threefold inter­penetrated two-dimensional supra­molecular architecture.

Two-dimensional Zn^II and one-dimensional Co^II coordination polymers based on benzene-1,4-di­carboxyl­ate and pyridine ligands

Reactions of benzene-1,4-di­carb­oxy­lic acid (H₂BDC) and pyridine (py) with Zn^II or Co^II yielded a two-dimensional Zn^II and a one-dimensional Co^II coordination polymer. In the former, centrosymmetric paddle-wheel-like Zn₂(μ₂-COO)₄ units are linked by benzene rings to generate a two-dimensional layered structure. The latter displays a one-dimensional double-chain structure based on Co₂(μ₂-COO)₂ units.

CB-TE2A⁺·Cl⁻·3H₂O: a short inter­molecular hydrogen bond between zwitterionic bi­cyclo­[6.6.2]tetra­amine macrocycles

The crystal structure of CB-TE2A⁺·Cl⁻·3H₂O is reported together with its comparison to closely related structures. The reason the macrocycle forms complexes with copper ions slowly is discussed.

Bis(tri­ethanol­amine)­bis­(μ₂-trimesato)dicobalt(II): a Co^II dimer with an unreported two-dimensional supra­molecular topology formed from tri­ethanol­amine and trimesic acid ligands

A Co^II dimer is described with an unreported two-dimensional supra­molecular topology formed from deprotonated trimesic acid and tri­ethanol­amine ligands. Four classical hydrogen bonds between carboxyl­ate groups and hy­droxy­ethyl arms stabilize and extend the zero-dimensional mol­ecules into a two-dimensional supra­molecular network. A variable-temperature magnetic study shows the existence of anti­ferromagnetic behaviour in the complex.

Synthesis, structural characterization and thermal properties of a new copper(II) one-dimensional coordination polymer based on bridging N,N′-bis­(2-hy­droxy­benzyl­idene)-2,2-di­methyl­propane-1,3-di­amine and dicyanamide ligands

In a new one-dimensional zigzag polymeric Cu^II complex based on bridging bis(salicylidene)propylenediamine-type Schiff base and dicyanamide ligands, the chelating characteristics of the Schiff base ligand result in the formation of a Cu^II dimer with a double phenolate bridge in the asymmetric unit.

Salt forms of the pharmaceutical amide di­hydro­carbamazepine

Although organic amides are often thought of as being nonbasic and hence non-ionizable, it is possible to protonate them using strong acids and to isolate their salt forms in the solid. We present here the structures of three salt forms of the pharmaceutically relevant amide di­hydro­carbamazepine and compare their mol­ecular and supra­molecular structures with those of di­hydro­carbamazepine and carbamazepine analogues.

A novel octa­nuclear nickel(II)–molybdenum(VI) heterometallic cluster based on the salicyl­hydroxamate ligand

Salicyl­hydroxamic acid is known for its strong coordination ability and multiple coordination modes. In a structure based on the salicyl­hydroxamate ligand, salicyl­hydroxamate(3−), acetate, hydroxide and oxide ligands adopt complicated coordination modes and link six Ni^II and two Mo^VI cations into an octa­nuclear heterometallic cluster. Studies of the magnetic properties reveal anti­ferromagnetic inter­actions between the Ni^II cations.

Synthesis and crystal structure of a two-dimensional sodium coordination polymer of 4,4′-(diazene­diyl)bis­(1H-1,2,4-triazol-5-one)

In the two-dimensional sodium(I) coordination polymer incorporating 4,4′-(diazenedi­yl)bis­(1H-1,2,4-triazol-5-one) (ZTO), each Na⁺ metal centre is bridged to a neigbouring Na⁺ cation by two water molecules to give a one-dimensional [Na(H₂O)₂]_n chain. The ZTO²⁻ ligand, an O atom of which also bridges the same pair of Na⁺ cations, then crosslinks these chains to form two-dimensional sheets. The two-dimensional sheets are further connected by inter­molecular hydrogen bonds.

Two cobalt(II) supra­molecular isomers based on N,N′-bis­(pyridin-3-yl)oxalamide induced by the mol­ecular orientation of lattice DMF mol­ecules

Two one-dimensional Co^II coordination polymers based on N,N′-bis­(pyridin-3-yl)oxalamide have been assembled by the solvothermal method. Single-crystal X-ray diffraction analyses reveal that the two compounds are supra­molecular isomers, the isomerism being induced by the orientation of di­methyl­formamide mol­ecules in the crystal lattice.