The supramolecular structures of the three metal (II) azido complexes [Fe(4bzpy)4(N3)2]; 1, [Ni(4bzpy)4(N3)2]; 2 and [Zn(4bzpy)2(N3)2]n; 3 with 4-benzoylpyridine (4bzpy) were presented. All complexes contain hexa-coordinated divalent metal ions with a slightly distorted octahedral MN6 coordination sphere. Complexes 1 and 2 are monomeric with terminal azido groups while 3 is one-dimensional coordination polymer containing azido groups with μ(1,1) and μ(1,3) bridging modes of bonding. Hirshfeld analysis was used to quantitatively determine the different contacts affecting the molecular packing in the studied complexes. The most common interactions are the polar O…H and N…H interactions and the hydrophobic C…H contacts. The charges at the M(II) sites are calculated to be 1.004, 0.847, and 1.147 e for complexes 1–3, respectively. The degree of asymmetry is the highest in the case of the terminal azide in complexes 1 and 2 while was found the lowest in the μ(1,1) and μ(1,3) azide bonding modes in the Zn(II) complex 3. These facts were further explained in terms of atoms in molecules (AIM) topological parameters.

Ligninolytic enzymes, such as laccase, lignin peroxidase and manganese peroxidase, are biotechnologically-important enzymes. The ability of five white-rot fungal strains Daedaleopsis confragosa, Fomes fomentarius, Trametes gibbosa, Trametes suaveolens and Trametes versicolor to produce these enzymes has been studied. Three different copper(II) complexes have been prepared ((Him)[Cu(im)4(H2O)2](btc)·3H2O, where im = imidazole, H3btc = 1,3,5-benzenetricarboxylic acid, [Cu3(pmdien)3(btc)](ClO4)3·6H2O) and [Cu3(mdpta)3(btc)](ClO4)3·4H2O, where pmdien = N,N,N′,N′′,N′′-pentamethyl-diethylenetriamine and mdpta = N,N-bis-(3-aminopropyl)methyl- amine), and their potential application for laccase and peroxidases induction have been tested. The enzyme-inducing activities of the complexes were compared with that of copper sulfate, and it has been found that all of the complexes are suitable for the induction of laccase and peroxidase activities in white-rot fungi; however, the newly-synthesized complex M1 showed the greatest potential for the induction. With respect to the different copper inducers, this parameter seems to be important for enzyme activity, which depends also on the fungal strains.

The molecular structures of chloride salts of 2and 5- substituted derivatives of 8- hydroxyquinoline, MeH 2 Q+ u Cl- ([ C 10 H 10 NO] Cl) and Cl- H 2 Q+ u Cl- ([ C 9 H 7 ClNO]+ u Cl-), were determined by single crystal X- ray diffraction methods; the latter is a new polymorph. In the crystal structures of these salts, several intra- and inter- molecular interactions result in a step- shaped centrosymmetric 4 4 R ( 8) ring. Unlike most quinolinium salts, there was no solvent present in these structures. Protonation of the quinoline N atom had an effect on the N uuu O bite distances and C- N- C angle and greater conjugation of the benzene ring with a hydroxyl group was also observed. p- p Interactions between each pair of quinolinium rings were observed in Me- H 2 Q+ u Clbut not in Cl- H 2 Q+ u Cl-. In addition, the quantum chemical calculations were performed on the new structures as well as similar compounds for comparison. The optimized structures were compared with the experimental observations for the effect of protonation and of hydrogen bonding interactions.

1-(1H-Benzimidazol-2-yl)-N-(1H-benzimidazol-2-ylmethyl)methanamine (abb) and 2-(1H-benzimidazol-2-ylmethylsulfanylmethyl)-1H-benzimidazole (tbb) have been prepared and characterized by elemental analysis. These bis(benzimidazoles) have been further used in combination with trithiocyanuric acid for the preparation of complexes. The crystal and molecular structures of two of them have been solved. Each nickel atom in the structure of trinuclear complex [Ni3(abb)3(H2O)3(μ-ttc)](ClO4)3·3H2O·EtOH (1), where ttcH3 = trithiocyanuric acid, is coordinated with three N atoms of abb, the N,S donor set of ttc anion and an oxygen of a water molecule. The crystal of [(tbbH2)(ttcH2)2(ttcH3)(H2O)] (2) is composed of a protonated bis(benzimidazole), two ttcH2 anions, ttcH3 and water. The structure is stabilized by a network of hydrogen bonds. These compounds were primarily synthesized for their potential antimicrobial activity and hence their possible use in the treatment of infections caused by bacteria or yeasts (fungi). The antimicrobial and antifungal activity of the prepared compounds have been evaluated on a wide spectrum of bacterial and yeast strains and clinical specimens isolated from patients with infectious wounds and the best antimicrobial properties were observed in strains after the use of ligand abb and complex 1, when at least 80% growth inhibition was achieved.

The Grignard reaction of 2,3-O-isopropylidene-α-D-lyxo-pentodialdo-1,4-furanoside and benzylmagnesium chloride (or bromide) afforded a non-separable mixture of diastereomeric benzyl carbinols and diastereomeric o-tolyl carbinols. The latter resulted from an unexpected benzyl to o-tolyl rearrangement. The proportion of benzyl versus o-tolyl derivatives depended on the reaction conditions. Benzylmagnesium chloride afforded predominantly o-tolyl carbinols while the application of benzylmagnesium bromide led preferably to the o-tolyl carbinols only when used in excess or at higher temperatures. The structures of the benzyl and o-tolyl derivatives were confirmed unambiguously by NMR spectral data and X-ray crystallographic analysis of their 5-ketone analogues obtained by oxidation of the corresponding mixture of diastereomeric carbinols. A possible mechanism for the Grignard reaction leading to the benzyl→o-tolyl rearrangement is also proposed.

The complexes of Fe(II), Mn(II) and Ni(II) with a combination of a Schiff base, nitrogen-donor ligand or macrocyclic ligand and trithiocyanuric acid (ttcH3) were prepared and characterized by elemental analysis and spectroscopies. Crystal and molecular structures of the iron complex of composition [Fe(L1)](ttcH2)(ClO4)·EtOH·H2O (1), where L1 is Schiff base derived from tris(2-aminoethyl)amine and 2-pyridinecarboxaldehyde, were solved. It was found that the Schiff base is coordinated to the central iron atom by six nitrogens forming deformed octahedral arrangement, whereas trithiocyanurate(1-) anion, perchlorate and solvent molecules are not coordinated. The X-ray structure of the Schiff base sodium salt is also presented and compared with the iron complex. The anticholinesterase activity of the complexes was also studied.

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.

Detailed kinetic and computational investigation of the enantio- and diastereoselective allylation of aldehydes 1 with allyltrichlorosilanes 5, employing the pyridine N-oxides METHOX (9) and QUINOX (10) as chiral organocatalysts, indicate that the reaction can proceed through a dissociative (cationic) or associative (neutral) mechanism: METHOX apparently favors a pentacoordinate cationic transition state, while the less sterically demanding QUINOX is likely to operate via a hexacoordinate neutral complex. In both pathways, only one molecule of the catalyst is involved in the rate- and selectivity-determining step, which is supported by both experimental and computational data.

The formation of methyl 4-cyano-6-deoxy-2,3-O-isopropylidene-α-l-talopyranoside (3), methyl 4-cyano-6-deoxy-2,3-O-isopropylidene-α-l-mannopyranoside (4), methyl 4-cyano-6-deoxy-2,3-O-isopropylidene-β-d-allopyranoside (5), and methyl 4-cyano-6-deoxy-2,3-O-isopropylidene-β-d-gulopyranoside (7) from methyl 6-deoxy-2,3-O-isopropylidene-α-l-lyxo-hexopyranosid-4-ulose (1) under Strecker amino nitrile synthesis and Bucherer-Bergs hydantoin synthesis reaction conditions, respectively, is reported. Their structures were determined on the basis of NMR and mass spectral data. The configurations of free cyanohydrins 3 and 4 and 4-O-acetylated cyanohydrins 6 and 8 (obtained by acetylation of 5 and 7, respectively) were established by single-crystal X-ray analysis. The conformations of the six-membered pyranose ring and five-membered 1,3-dioxolane ring in compounds 3, 4, 6, and 8 are also reported.

AbstractSamples containing 46, 49, and 51 wt.% Cr2O3 (primary crystallization field in the CaO—Cr2O3 system) in a mixture of CaCO3, CrO3, HNO3, and H2O are slowly heated to 1173 K and show the presence of Ca5(CrO4)3OH and CaCrO4.

The structure analysis of so-called 9CaO·4CrO(3)·Cr(2)O(3) proved it to be the title compound, decacalcium hexakis[chromate(V)] chromate(VI), with the simultaneous presence of unusual chromium oxidation states. The structure determination was carried out on a crystal that had inversion twinning. The Cr(VI)O(4) tetrahedron is situated on a threefold axis and is disordered over two possible orientations that share three O atoms, while the Cr(V)O(4) tetrahedra are in general positions and are ordered. The charge is balanced by Ca(2+) cations, one of which is located on a threefold axis. The Ca(2+) ions are coordinated by six, seven or eight O atoms. The compound is a significant phase in the CaO-CrO(x) system and its formation reduces the refractoriness of calcium-rich compositions in an oxidizing atmosphere.

In the structure of trans-bis(ethanol-κO)tetrakis(1H-imidazole-κN(3))copper(II) bis[μ-N-(2-oxidobenzylidene)-D,L-glutamato]-κ(4)O(1),N,O(2'):O(2');κ(4)O(2'):O(1),N,O(2')-bis[(1H-imidazole-κN(3))cuprate(II)], [Cu(C(3)H(4)N(2))(4)(C(2)H(6)O)(2)][Cu(2)(C(15)H(14)N(3)O(5))(2)], both ions are located on centres of inversion. The cation is mononuclear, showing a distorted octahedral coordination, while the anion is a binuclear centrosymmetric dimer with a square-pyramidal copper(II) coordination. An extensive three-dimensional hydrogen-bonding network is formed between the ions. According to B3LYP/6-31G* calculations, the two equivalent components of the anion are in doublet states (spin density located mostly on Cu(II) ions) and are coupled as a triplet, with only marginal preference over an open-shell singlet.

A new unsymmetrical Schiff base ligand HL1, HBacabza, and its copper(II) complexes [Cu2L12(OAc)2] (1) and [Cu2L22(N3)2]·2H2O (2) with HBacabza=3-(2-aminobenzylimino)-1-phenylbutan-1-one as HL1 and its hydrolytically rearranged isomer 3-(2-aminomethylphenyleneimino)-1-phenylbutan-1-one as HL2, have been synthesized and characterized by elemental analyses and spectroscopic methods. The rearrangement of HL1 to HL2 occurs in a hydrolysis-recondensation process in the reaction of HL1 with Cu(ClO4)2·6H2O and NaN3. The crystal structures of the ligand and its complexes have been determined by single crystal X-ray diffraction. The deprotonated Bacabza− coordinates to the metal center as a tridentate ligand. The acetate anion coordinates through one oxygen atom in complex 1 leading to a mono-atomic acetate oxygen-bridging dimeric copper(II) complex. Similarly, the azide anion coordinates through one nitrogen atom in complex 2 leading to a mono-atomic azide nitrogen-bridging dimeric copper(II) complex. The copper(II) ions adopt a distorted square pyramidal (4+1) coordination in these two complexes. The cyclic voltammetric studies of these complexes in N,N-dimethylformamide indicate that the reduction process corresponding to CuII/CuI is electrochemically irreversible in complex 1, presumably due to the structural changes during the course of redox reaction, and quasi-reversible in complex 2.

Synthesis and structure elucidation of new series of novel fused 1,2,4-triazine derivatives 3a-3f, 4a-4i and 6a-6b and their inhibitory activities are presented. Molecular structures of the synthesized compounds were confirmed by (1)H NMR, (13)C NMR, MS spectra and elemental analyses. X-ray crystallographic analysis was performed on 2-acetyl-8-(N,N-diacetylamino)-6-(4-methoxybenzyl)-3-(4-methoxy-phenyl)-7-oxo-2,3-dihydro-7H-[1,2,4]triazolo[4,3-b][1,2,4]triazine 3d and 2-acetyl-8-(N-acetylamino)-6-benzyl-3-(4-chlorophenyl)-3-methyl-7-oxo-2,3-dihydro-7H-[1,2,4]triazolo[4,3-b][1,2,4]triazine 4e to secure their structures. The inhibitory effect of these compounds toward the CPY1A1 activity was screened to determine their potential as promising anticancer drugs. Our data showed that compounds 4e, 5a, 5b and 6b possess the highest inhibitory effects among all tested compounds. Furthermore, analysis of triazolotriazine derivatives docking showed that these compounds bind only at the interface of substrate recognition site 2 (SRS2) and (SRS6) at the outer surface of the protein. Amino-acids ASN214, SER216 and ILE462 participate in the binding of these compounds through H-bonds.

The title complex [Pd(Me2bqb)] (1), [Me2bqb2– = 1,2-bis(quinoline-2-carboxamide)-4,5-dimethyl-benzene dianion], has been synthesized and characterized by elemental analyses and spectroscopic methods, and the crystal and molecular structure of [Pd(Me2bqb)] has been determined by X-ray crystallography. The complex exhibits distorted square-planar PdN4 coordination geometry with two short and two long Pd–N bonds (Pd–N ~1.957 and ~2.095 Å, respectively). In addition to the molecular geometry from X-ray experiment, theoretical studies have been carried out on the structure of the complex at the density functional theory (DFT-B3LYP) level in conjunction with effective core potential basis set (LANL2DZ) for Pd atom and 6-311++G(d,p) basis set for N, O, C and H atoms. Electrochemical studies in CH2Cl2 solution revealed A reversible redox process corresponding to the PdII/PdIII couple with E 1/2 at 0.924 V (vs. SCE).

In the title benzilidene Schiff base molybdenum(VI) complex, [Mo(C15H12N2O3)O2(CH3OH)], the MoVI ion is coordinated by two oxide O atoms and by two O atoms and one N atom of the tridentate N′-(3-methoxy-2-oxidobenzylidene)benzohydrazidate (L) Schiff base ligand. The methanol O atom completes the distorted octahedral configuration of the MoVI atom. Strong O—H...N hydrogen bonds form a C(5) chain around a 21 screw axis. Weak C—H—O hydrogen bonds are also present.

Synthesis of bis-4,5-diazafluoren-9-one silver(I) nitrate I (dafone = 4,5-diazafluoren-9-one) and the low temperature X-ray single crystal structure of [Ag(4,5-diazafluoren-9-one)2NO3], crystal form 1, and a re-determination of [Ag(4,5-diazafluoren-9-one)2]NO3·H2O, crystal form 2 are presented. Crystal form 1 has a distorted trigonal planar coordination geometry around Ag(I) with an N–Ag–N bond angle of 123.45(7)°. Crystal form 2 has a perfect linear coordination around Ag, with N–Ag–N 180.0°. Compound I was characterized by 1H-NMR, biological activity and ESI-MS in DMSO at room temperature. The biological activity was determined against 6 different resistant clinical isolates; two Gram-positive (Staphylococcus aureus and Streptococcus pyogenes) and four Gram-negative (Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis, and Salmonella sp.) in comparison with 15 known antibiotics used in the treatment of diabetic foot infections. Compound I showed broad spectrum activity against all the test organisms. P. mirabilis and S. aureus and K. pneumoniae were the most sensitive clinical isolates (MIC = 4, 6 and 4 μg ml−1, respectively). Three different hydrogels containing I or Ag2SO4 were prepared and the antimicrobial activity against Ps. aeruginosa (ATCC 15442) compared, showing more or less equal activity on a weight basis, but I seems to have a significant better performance per silver ion. The Ag(I) complex also binds more effectively to calf thymus DNA than the dafone ligand itself.

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.

The coordination polymer [Fe(SCN)2(1,2-bis(4-pyridylmethylene)hydrazine)2]n [Fe(phenanthroline)3]2n(ClO4)2n·n1,2-bis(4-pyridylmethylene)hydrazine·4nH2O 1 was crystallised from a MeOH/MeCN solution and the structure consists of layered (4,4) 2D-nets with supramolecular ([Fe(phen)3]2bphz)4+ units in the pores and disordered water and perchlorate anions. The same supramolecular motif could be independently prepared as [Fe(phen)3]2·bphz(ClO4)4·xMeOH 2, and the [Ru(phenanthroline)3]2+ compound 3, isostructural to 1, was also prepared although a complete structure determination was prevented by low crystal quality. Compounds 1 and 3 are rare examples of how several large and different components can be assembled inside a 2D coordination network and provide a concept for multi-component self-assembly.