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Synthesis and structural characterization of two heterodinuclear ZnII-LnIII complexes with the formula [ZnLn(HL)(µ-OAc)(NO3)2(H2O)x(MeOH)1-x]NO3 · n H2O · n MeOH [Ln = Pr (1), Nd (2)] and the crystal and molecular structure of [ZnNd(HL)(µ-OAc)(NO3)2(H2O)] [ZnNd(HL)(OAc)(NO3)2(H2O)](NO3)2 · n H2O · n MeOH (3) are reported. The asymmetrical compartmental ligand (E)-2-(1-(2-((2-hydroxy-3-methoxybenzylidene)amino)-ethyl)imidazolidin-2-yl)-6-methoxyphenol (H2L) is formed from N1,N3-bis(3-methoxysalicylidene)diethylenetriamine (H2valdien) through intramolecular aminal formation, resulting in a peripheral imidazoline ring. The structures of 1–3 were revealed by X-ray crystallography. The smaller ZnII ion occupies the inner N2O2 compartment of the ligand, whereas the larger and more oxophilic LnIII ions are found in the outer O2O2’ site. Graphic Abstract Synthesis and structural characterization of two heterodinuclear ZnII-LnIII complexes (Ln = Pr, Nd) bearing an asymmetrical compartmental ligand formed in situ from N1,N3-bis(3-methoxysalicylidene)diethylenetriamine (H2valdien) through intramolecular aminal formation are reported.

In this paper, we report on the chiral crystallization of achiral mol­ecules., The compound, {6,6′-dimeth­oxy-2,2′-[(4-azaheptane-1,7-di­yl)bis­(nitrilo­meth­an­yl­idyne)]diphenolato}zinc(II) methanol monosolvate, [Zn(C22H27N3O4)]·CH3OH, at 298 K crystallizes in the ortho­rhom­bic space group Pna21. The Zn atom is coordinated by a penta­dentate Schiff base ligand in a distorted trigonal–bipyramidal N3O2 geometry. The equatorial plane is formed by the two phenolic O and one amine N atom. The axial positions are occupied by two amine N atoms. The distorted bipyramidal geometry is also supported by the trigonality index (τ), which is found to be 0.85 for the mol­ecule. In the crystal, methanol solvent mol­ecule is connected to the complex mol­ecule by an O—H⋯O hydrogen bond and the complex mol­ecules are connected by weak supra­molecular inter­actions, so achiral mol­ecules generate a chiral crystal. The Hirshfeld surface analysis suggests that H⋯H contacts account for the largest percentage of all inter­actions.

The crystal and molecular structure of [Cu2(H2valdien)2](NO3)2 (1), whereby H2valdien is the known Schiff base ligand N1,N3-bis(3-methoxysalicylidene)diethylenetriamine, is reported. In 1, two H2valdien ligands join two CuII ions in a chelate–spacer–chelate mode, in which the protonated aliphatic secondary amine moieties represent the spacers, to form a double helix. Both CuII ions in the homodinuclear cationic complex exhibit similar distorted square-planar N2O2 coordination spheres. The axially chiral molecular structure of the [Cu2(H2valdien)2]2+ complex features intramolecular π···π stacking and N–H⋯O hydrogen bonds in the crystal. Compound 1 crystallizes in the Sohncke space group P21, with a = 14.165(3), b = 13.7755(13), c = 21.1185(4) A, β = 102.199(4)°, and with two enantiomeric molecules in the asymmetric unit (Z′ = 2). The two crystallographically unique [Cu2(H2valdien)2]2+ enantiomers are related by pseudo inversion symmetry. The pseudo centrosymmetric chiral Z′ = 2 crystal structure (space group P21) of [Cu2(H2valdien)2](NO3)2, whereby H2valdien is the known Schiff base ligand N1,N3-bis(3-methoxysalicylidene)diethylenetriamine, is reported.

Department of Chemistry, Faculty of Science, Tokyo University of Science, Shinjuku-ku, Tokyo, Japan E-mail : akitsu@rs.kagu.tus.ac.jp Department of Electrical Engineering, Faculty of Science and Technology, Tokyo University of Science, Chiba, Japan Department of Chemistry, Aligarh Muslim University, Aligarh-202 002, Uttar Pradesh, India Manuscript received 02 May 2017, accepted 08 May 2017 Dye sensitized solar cells (DSSC) emerged as a new class of low cost energy conversion devices. In this study, we investigated a class of transition metal complexes [ML(CH3OH)]; M = Mn(1), Fe(2), Co(3), Ni(4), Cu(5) and Zn(6) and H2L is naphthyl-salen Schiff base ligand. The COOH group of the complexes leads to better ability for adsorption of dyes. These complexes were characterized employing elemental analysis, powder X-ray analysis, IR, UV-Vis-NIR electronic spectroscopy and so on. Light absorption of the all the complexes shows that π-conjugated naphthyl ring makes these complexes efficient as dyes in DSSC. However, spatial distribution of excited orbitals associated with absorption properties (UV-Vis absorption spectra) calculated by TD-DFT method revealed one of the important factors about orbitals and molecular design of metal complexes for DSSC dyes.

The crystal structure of the organic–inorganic title salt, [Mn(C18H18N2O4)(H2O)2]ClO4, has been redetermined at 100 K. In contrast to the crystal structure determinations at room temperature [Akitsuet al.(2005).Acta Cryst. C61, m324–m328; Bermejoet al.(2007).Eur. J. Inorg. Chem.pp. 3789–3797], positional disorder of the ethylene bridge in the Schiff base ligand and the perchlorate anion is not observed at 100 K. The MnIIIion is six-coordinated with the tetradentate Schiff base chelate ligandN,N′-bis(3-methoxy-2-oxybenzylidene)ethylenediamine occupying coordination sites in the equatorial plane and the aqua ligands residing in the two axial positions. The octahedral coordination sphere of the MnIIIion exhibits an axial elongation due to the Jahn–Teller effect, which is characteristic of ad4high-spin electronic configuration.

In the crystal structure of the title mononuclear CuIIcomplex, [Cu(C11H16N3O2)(NO3)]·0.25C2H5OH, the complex molecules are linked by N—H...O and O—H...O hydrogen bonds, forming a dimer with an approximate non-crystallographic twofold rotation axis of symmetry. In the monomeric unit, the Cu2+ion exhibits a distorted square-pyramidal configuration, whereby the anionic [HL]−Schiff base ligand binds in a tetradentate fashionviathe O and the three N atoms which all are approximately coplanar. The O atom of a nitrate anion occupies the fifth coordination site, causing the CuIIatom to move slightly out of the approximate basal plane toward the bound nitrate group. The structure exhibits disorder of the ethanol solvent molecule.

Spectral and molecular model computations on homo-dinuclear complexes [M(2)L(2)(H(2)O)(2)Cl(2)] [L=1-(salicylaldeneamino)-3-hydroxypropane, M=Cr(3+), Mn(3+), Fe(3+), Co(3+), Ni(3+) or Cu(3+)] are consistent with a distorted hexa-coordinate geometry. X-band EPR spectral data indicated a rhombic distortion around Cu(II) ion. Magnetic moment and (57)Fe Mössbauer data confirmed a high-spin state electronic configuration (t(2g)(3)e(g)(2), S=5/2) and asymmetric ligand environment around Fe(III) with nuclear transitions Fe(+/-3/2--1/2) exhibiting Kramer's double degeneracy. The neighboring Fe(III) nuclei in the homo-dinuclear species are antiferromagnetically coupled.

Two novel dinuclear organotin(IV) complexes [n-Bu2Sn(imda)(H2O)]2·Bipy (1) and [n-Bu2Sn(imda)(H2O)]2·Phen (2) [H2imda = iminodiacetic acid, Bipy = 2,2′-bipyridine and Phen = 1,10-phenanthroline] were synthesised and characterized employing IR, 1H, 13C, 119Sn NMR, and 119Sn Mossbauer spectroscopic and elemental analyses. Single crystal X-ray crystallography of 1 has confirmed that it is a binuclear Sn(IV) species formed via carboxylate bridges where each metal adopted a seven coordinate distorted pentagonal bipyramidal geometry. The iminodiacetate dianion (imda2−) acts as a potential tridentate [N,O,O] carboxylate bridging ligand. The packing revealed that the additional α-diimine (Bipy or Phen) does not coordinate to metal ion. However, its presence in the crystal lattice as spacer helps for the formation of a supramolecular framework by bringing the two binuclear species close enough through extensive H-bonding. The in vitro cytotoxicity of compounds 1 and 2 indicate better results than cisplatin against three tumor cell lines investigated.

The title compound, [Cu(C20H23N3O4)], crystallizes in the space groupCcwith two independent molecules in the asymmetric unit. The CuIIatoms are each coordinated by the pentadentate Schiff base ligand in a distorted trigonal bipyramidal N3O2geometry. The equatorial plane is formed by the two phenolic O atoms and the amine N atom, while the axial positions are occupied by the two imine N atoms. In the crystal, the two independent molecules are each connected into a column along thebaxis through intermolecular O—H...O hydrogen bonds. The two independent columns are further linked through an N—H...O hydrogen bond, forming a double-column structure.

INTRODUCTION To describe the optic disc, visual field and ocular characteristics of a consecutive cohort of Asian patients with chronic primary angle-closure glaucoma (CPACG), and compare them with those having primary open-angle glaucoma (POAG). METHODS In a prospective comparative case series of new patients with POAG or CPACG in Singapore, all patients underwent visual acuity assessment, slit-lamp examination, tonometry, gonioscopy, refraction, Heidelberg Retina Tomograph (HRT) and Humphrey visual field (HVF) assessment. RESULTS 98 patients were enrolled (POAG n = 48; CPACG n = 50). CPACG patients were significantly older (66.5 ± 9.2 years vs. 64.1 ± 13.5 years; p = 0.027) and mostly female (p = 0.004). CPACG eyes had significantly higher intraocular pressure (26.9 ± 6.9 mmHg vs. 24.5 ± 3.3 mmHg; p = 0.03), shorter axial length (22.89 ± 0.97 mm vs. 24.26 ± 1.79 mm; p < 0.001) and shallower anterior chamber depth (2.60 ± 0.25 mm vs. 3.16 ± 0.48 mm; p < 0.001). HVF mean deviation or pattern standard deviation (PSD) did not differ significantly between POAG and CPACG eyes, but the latter had a lower PSD for a given mean deviation. HRT parameters between the two groups were not significantly different. CONCLUSION In this study, CPACG eyes had significantly higher presenting intraocular pressure than POAG eyes, but there were no significant differences in optic disc topography. A majority of the patients in both groups had moderate field defects at the time of presentation, followed by severe and then mild defects. The field loss in CPACG eyes was more diffuse than that in POAG eyes.

The title complexes were prepared and characterized employing spectral (FAB-Mass, IR, electronic, 1 H and 13 C NMR), thermal and electrochemical techniques. Analytical and FAB-Mass data suggested a homo-dinuclear stoichiometry. IR and electronic ligand field spectral studies coupled with molecular model computations have indicated a distorted octahedral geometry where the ligand coordinates as a hexadentate dianionic [H 3 DTPA] 2− (H 5 DTPA = diethylenetriaminepentaacetic acid) moiety. The electrochemical redox properties and the antibacterial activities of the compounds were also investigated.

Ternary complexes are potential models for several mono and polynuclear metal enzymes. The present ternary complexes [Fe(dipic)(4-picoline)]Cl, [M(dipic)(4-picoline)] [M = Co or Ni] and [Cu(dipic)(4-picoline)]n were prepared to exploit as novel antimicrobial agents. The chemical structure and bonding etc. were elucidated by spectral studies. Single crystal X-ray data of the Cu(II) complex indicated formation of 1D coordination polymeric structure. The antimicrobial activities investigated against Escherichia coli (K-12), Bacillus subtilis (MTCC-121), Staphylococcus aureus (IOA-SA-22), Salmonella typhymurium (MTCC-98), Candida albicans, Aspergillus fumigatus and Penicillium marneffei (isolates from Department of Microbiology, Faculty of Agricultural Science, AMU) showed significant activities. The superoxide dismutase (SOD) activity of the Cu(II) complex was also assessed by NBT assay.

The newly prepared homo-bimetallic complexes [M 2 (imda) 2 (H 2 O) 4 ], [M 2 (imda) 2 (Bipy) 2 ] (M = Co, Ni or Cu) and [Fe 2 (imda) 2 (H 2 O) 3 Cl] (H 2 imda = iminodiacetic acid and Bipy = 2,2′-bipyridine) have been studied employing IR, FAB-mass, 1 H and 13 C NMR, EPR and ligand field spectra, which indicated a high-spin state of metal ion with hexa-coordinate environment. 57 Fe Mossbauer data of the homo-bimetallic complex [Fe 2 (imda) 2 (H 2 O) 3 Cl] confirm a high-spin configuration with Fe (±3/2 → 1/2) nuclear transitions and the presence of Kramer's double degeneracy. At RT, the spin–spin interactions of the neighbouring nuclei (Fe 3+ –Fe 3+ = S 5/2 –S 5/2 ) are anti-ferromagnetically coupled. However, at LNT, the complex acquires a mixed-valent [Fe III –Fe II ] composition corroborated from the X-band EPR data. CV studies indicated the presence of quasi-reversible redox Cu II/I , Cu II/III , Fe III/II , Fe III/I and Fe II/I couples.