Al-Shimaà A A Massoud

Effects of Different Substituents on the Crystal Structures and Antimicrobial Activities of Six Ag(I) Quinoline Compounds

The syntheses and single crystal X-ray structures of [Ag(5-nitroquinoline)2]NO3 (1), [Ag(8-nitroquinoline)2]NO3·H2O (2), [Ag(6-methoxy-8-nitroquinoline)(NO3)]n (3), [Ag(3-quinolinecarbonitrile)(NO3)]n (4), [Ag(3-quinolinecarbonitrile)2]NO3 (5), and [Ag(6-quinolinecarboxylic acid)2]NO3 (6) are described. As an alternative to solution chemistry, solid-state grinding could be used to prepare compounds 1 and 3, but the preparation of 4 and 5 in this way failed. The Ag(I) ions in the monomeric compounds 1, 2, 5, and 6 are coordinated to two ligands via the nitrogen atoms of the quinoline rings, thereby forming a distorted linear coordination geometry with Ag-N bond distances of 2.142(2)-2.336(2) Å and N-Ag-N bond angles of 163.62(13)°-172.25(13)°. The 1D coordination polymers 3 and 4 contain Ag(I) centers coordinating one ligand and two bridging nitrate groups, thereby forming a distorted trigonal planar coordination geometry with Ag-N bond distances of 2.2700(14) and 2.224(5) Å, Ag-O bond distances of 2.261(4)-2.536(5) Å, and N-Ag-O bond angles of 115.23(5)°-155.56(5)°. Hirshfeld surface analyses of compounds 1-6 are presented as d(norm) and curvedness maps. The d(norm) maps show different interaction sites around the Ag(I) ions, i.e., Ag···Ag interactions and possible O-H···O, C-H···O, C-H···N, and C-H···C hydrogen bonds. Curvedness maps are a good way of visualizing π-π stacking interactions between molecules. The antimicrobial activities of compounds 1, 2, and 6 were screened against 15 different multidrug-resistant strains of bacteria isolated from diabetic foot ulcers and compared to the antimicrobial activities of the clinically used silver sulfadiazine (SS). Compound 2 showed activity similar to SS against this set of test organisms, being active against all strains and having slightly better average silver efficiency than SS (5 vs 6 μg Ag/mL). Against the standard nonresistant bacterial strains of Staphylococcus aureus , Pseudomonas aeruginosa , Proteus mirabilis , and Streptococcus pyogenes , compound 1 performed better than silver nitrate, with an average MIC of 6 μg Ag/mL versus 18 μg Ag/mL for the reference AgNO3. Electrospray ionization mass spectrometry (ESI-MS) analyses of compounds 3 and 6 in DMSO/MeOH confirm the two-coordinated Ag(+) complexes in solution, and the results of the (1)H NMR titrations of DMSO solutions of 5-nitroquinoline and 8-nitroquinoline with AgNO3 in DMSO suggest that 5-nitroquinoline is more strongly coordinated to the silver ion.

Methyl groups control coordination number, stoichiometry, network and magnetism in a Cu(II)-azide-pyrazine (6,3) 2D net

The methyl groups of [Cu2(2,5-dimethylpyrazine)(N3)4]n, 1, force penta-coordination on the Cu(II) ions, which, together with the di-µ-1,1azido zigzag chains, result in a (6,3) 2D net with dominant ferromagnetic interactions.

Two 2-D copper(II) azido compounds: catena -poly[ di -μ1,1- azido, di -μN,O-(quinolinecarboxylato)(aqua)copper(II)] and 1-D catena -poly[ di -μN,N′-(quinoxaline)copper(II)nitrate]

We synthesized three copper(II) complexes with two structurally related polydentate ligands, quinoline-4-carboxylic acid (quCOOH) and quinoxaline (qux). The structures of these complexes were determined using X-ray single crystal crystallography. Complex 1, [Cu(quCOO)(N3)(H2O)] n , has a 2-D polymeric structure through di-μ1,1 azido groups forming (Cu2N2) dimeric units and di-μN,O quinoline carboxylate bridging the binuclear copper units. [Cu(quCOO)(N3)(H2O)] n · 0.87MeOH, (2), has the same structure as 1 in addition to MeOH molecules separating the 2-D sheets of [Cu(quCOO)(N3)(H2O)] n . [Cu(qux)(NO3)2] n , (3), has no coordinated azido groups, but the quinoxaline is a bidentate bridging ligand giving a 1-D chain, while the μO,O′ chelating nitrato groups stabilize the chain structure by forming a square planar coordination sphere around copper. IR and UV–Vis spectra of the complexes are in agreement with the crystal structures.

Bis(1,3,5-triazine-2,4,6-triamine-κN1)silver(I) nitrate

The title compound, [Ag(C(3)H(6)N(6))(2)]NO(3), has an alternating two-dimensional bilayer structure supported by extensive hydrogen bonds. The [Ag(melamine)(2)](+) cationic monomers (melamine is 1,3,5-triazine-2,4,6-triamine) are connected via N-H...N hydrogen bonds to form two-dimensional sheets. Nitrate groups are sandwiched between two sheets through N-H...O hydrogen bonds. An almost perfectly linear coordination geometry is found for the Ag(I) ions. The triazine ligands are slightly distorted due to pi-pi interactions.

The coordination polymer poly[(μ3-3-aminocarbonylpyrazine-2-carboxylato-κ3N1:O2:O2')silver(I)]

The title compound, [Ag(C(6)H(4)N(3)O(3))](n) or [Ag(pyzca)](n) (where pyzca is 3-aminocarbonylpyrazine-2-carboxylate), (I), was obtained by silver-catalysed partial hydrolysis of pyrazine-2,3-dicarbonitrile in aqueous solution. The compound has a distorted trigonal-planar coordination geometry around the Ag(I) ion, with each ligand bridging three Ag(I) ions to form a one-dimensional strand of molecules parallel to the b axis. An extensive hydrogen-bond pattern connects these strands to form a three-dimensional network of mog topology.

Bis[4-(dimethylamino)pyridine-κN1]silver(I) nitrate dihydrate

The title compound, [Ag(C(7)H(10)N(2))(2)]NO(3).2H(2)O or [Ag(dmap)(2)]NO(3).2H(2)O, where dmap is 4-(dimethylamino)pyridine, has a distorted linear coordination geometry around the Ag(I) ion. A novel pattern of water-nitrate hydrogen-bonded anionic strands is formed in the c direction, with the cationic [Ag(dmap)(2)](+) monomers trapped between them. The Ag(I) ion and the nitrate group atoms, as well as the water molecules (including the H atoms), are on a crystallographic mirror plane (Wyckoff position 4a). The influence of bulky methyl substituents in position 4 of the 4-(dimethylamino)pyridine ligand on packing is discussed. The absolute structure was determined unequivocally.

Bis[4-(dimethylamino)pyridine-κN 1 ]silver(I) nitrate dihydrate

The title compound, [Ag(C(7)H(10)N(2))(2)]NO(3).2H(2)O or [Ag(dmap)(2)]NO(3).2H(2)O, where dmap is 4-(dimethylamino)pyridine, has a distorted linear coordination geometry around the Ag(I) ion. A novel pattern of water-nitrate hydrogen-bonded anionic strands is formed in the c direction, with the cationic [Ag(dmap)(2)](+) monomers trapped between them. The Ag(I) ion and the nitrate group atoms, as well as the water molecules (including the H atoms), are on a crystallographic mirror plane (Wyckoff position 4a). The influence of bulky methyl substituents in position 4 of the 4-(dimethylamino)pyridine ligand on packing is discussed. The absolute structure was determined unequivocally.