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Polyhedron
Pergamon Press
Polyhedron

Pergamon Press

0277-5387

Polyhedron/Journal PolyhedronSCICCREI
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    Photodynamic evaluation of triazine appended porphyrins as anti-leishmanial and anti-tumor agents

    Manathanath, MonishaSasidharan, SantanuSaudagar, PrakashPanicker, Unnikrishnan Gopalakrishna...
    10页
    查看更多>>摘要：Many recent advancements in porphyrin based photodynamic therapy are being treated as revolutionary in the field of medicinal chemistry, as they offer effective and viable solutions for many serious diseases including cancer. Motivated by the exceptional bioactivity of triazine moieties, we designed 4,6-diamino-1,3,5-triazine appended 5,10,15,20-tetrakis(4-hydroxyphenyl)porphyrin (THP) and it's metal derivatives; adopting a mild and effective microwave assisted protocol. All the synthesized derivatives were evaluated in-vitro for their anti proliferative activity against human malignant melanoma (A375), human breast cancer (MCF-7) and promastigote form of Leishmania donovani by MTT assay in the presence of light. The study revealed better inhibitory activity of the derivatives under illumination, compared to the parent compound. The compounds were found to be non-toxic to normal cells at their respective concentrations of anti-proliferative action, in both dark and light. The cellular uptake of the compounds in tumor cell was confirmed using laser confocal fluorescence microscopy. In order to establish the mechanism of action, the singlet oxygen generation efficiency was also investigated. The superior inhibitory activity of the zinc derivative has been indicated by its highest singlet oxygen generation efficiency (phi(delta) = 0.69).
      原文链接:
    • NSTL
    • Elsevier

    Indium complexes of chlorin e(6 )trimethyl ester and methylpyropheophorbide a: Synthesis and photophysical characterization

    Rychikhina, EkaterinaIvanova, Svetlana S.Romanenko, Yulia V.Koifman, Oskar I....
    7页
    查看更多>>摘要：Complexes of chlorin e6 trimethyl ester (H(2)Chl-e(6),), methylpyropheophorbide a (H2MePyroPheo) with indium (III) (InChl-e(6), and InMePyroPheo) were obtained from the corresponding macrocyclic ligands by complexation reaction with InIII trisacetylacetonate in acetic acid. In the case of methylpheophorbide a (H2MePheo) the complexation reaction is accompanied by side-process of exo-cyclic ring oxidation leading to inseparable mixture of InMePheo, its 13(2)-hydroxy derivative and InMePyroPheo. Spectral-luminescence and photophysical properties of H(2)Chl-e(6) and H(2)MePyroPheo and their In-III complexes were studied in DMF. Metal free chlorins have relatively long fluorescence lifetimes ((sic)(f) 5.4-7.5 ns) and moderate fluorescence and singlet oxygen quantum yields (Phi(F) ~& nbsp;0.39 and 0.29, Phi(delta & nbsp;)~& nbsp;0.47 and 0.60, for H(2)Chl-e(6) and H(2)MePyroPheo, respectively). It was revealed that insertion of the indium atom into the macrocyclic core strongly diminishes the fluorescence lifetimes ((sic)(f) 0.5-0.9 ns) and quantum yields (Phi(F) ~& nbsp;0.04-0.06), but facilitates the conversion to the triplet state leading to enhanced singlet oxygen quantum yields. Therefore, InChl-e(6) and InMePyroPheo having intense Q-band absorption in the therapeutic window (638 and 661 nm) and high values of Phi(delta) (0.84 and 0.76) can be considered as promising photosensitizers for PDT.
      原文链接:
    • NSTL
    • Elsevier

    Enhanced hydrophobicity of modified ZIF-71 metal-organic framework for biofuel purification

    Tiempos-Flores, NormaHernandez-Fernandez, EugenioRico-Barragan, AlanJuarez-Ramirez, Isaias...
    6页
    查看更多>>摘要：Hydrophobic materials are desirable for biofuel purification applications. In this work, the atomic substitution of Cl atom with Br atom in the imidazole organic linker was carried out to produce a more hydrophobic ZIF-71, named ZIF-71(ClBr) and ZIF-71(ClBr)-SE for the material with an additional solvent exchange procedure. The physicochemical characterization revealed that ZIF-71(ClBr) and ZIF-71(ClBr)-SE are isostructural to ZIF-71, have a high surface area (769 and 969 m(2)/g), and are hydrophobic (126 and 130 degrees water contact angle). As a proof of concept, D4 siloxane adsorption capacity onto ZIF-71(ClBr) and ZIF-71(ClBr)-SE was estimated (1.76 and 2.66 mg/g, respectively). Furthermore, a superior adsorption capacity was obtained when ZIF-71(ClBr)-SE was used due to its higher hydrophobic nature, and similar results were obtained with ZIF-8, used as a frame of reference. Therefore, the high surface area and the hydrophobic nature of ZIF-71(ClBr)-SE make it compelling material for biofuel purification applications.
      原文链接:
    • NSTL
    • Elsevier

    Synthesis and characterisation of eta(6)-arene (halogenidoaluminato)-lanthanoid(II) and alkaline earth(II) complexes

    Hossain, Md. EliusGuo, ZhifangWang, JunDeacon, Glen B....
    8页
    查看更多>>摘要：eta(6)-Arene(iodidoaluminato)lanthanoid(II) complexes, {[Ln(eta(6)-C6H5Me)(AlI4)(2)]}(n) [Ln = Sm, 1, Eu, 2, Yb, 3; C6H5Me = toluene] have been prepared by reactions of in situ generated aluminium triiodide with the corresponding lanthanoid metals and 1,2-diiodoethane in toluene (molar ratio: 2:1:1). Compounds 1-3 are polymeric and the lanthanoid(II) atom of 1 and 2 is coordinated by an eta(6)-arene and three chelating kappa (I, I') tetraiodidoaluminate ligands, two of which are also bridging (LnI(2)AlI(2)Ln) and one is terminal. 3 is coordinated by an eta(6)-arene, one terminal chelating kappa (I, I') and one chelating and bridging (YbI2AlI2Yb) tetraiodidoaluminate ligand, and one monodentate tetraiodidoaluminate ligand, which is also bridging (YbIAl(I)I2Yb). These are the first X-ray crystal structures of arene(tetrakisiodidoaluminato)lanthanoid(II) complexes. The first reported alkaline earth(II) (eta(6)-arene)iodidoaluminate complexes, namely [Ca(eta(6)-C6H5Me)(AlI4)(2)](n) (4), {[Sr(eta(6)-C(6)H5Me)(AlI4)(2)](n)middotnPhMe} (5), [Ba(eta(6)-C6H5Me)(2)(AlI4)(2)] (6), [Ca(eta(6)-C6H3Me3-1,3,5)(AlI4)(2)](n) (7) and {[Sr(eta(6)-C6H3Me3-1,3,5)(AlI4)(2)](n)middot0.5n(PhMe3)} (8) have also been obtained in an arene (toluene or mesitylene) solution by a similar method. Complex 4 is isocoordinate with 3, and 5 is isomorphous with 2. Complex 7 has eight coordinate Ca similar to 4, and complex 8 has nine coordinate Sr as in 5. Mononuclear ten coordinate complex 6 is the first example of a monomeric eta(6)-arene sandwich complex of barium. The Eu-II bromidoaluminate complex {[Eu(eta(6)-C6H5Me)(AlBr4)(2)](n)middot0.5nPhMe} (9) has been prepared from Eu metal, AlBr3, and BrCH2CH2Br in toluene and has a unit cell similar to 8 despite the different metal and arene.
      原文链接:
    • NSTL
    • Elsevier

    Heteroleptic carbazolato-barium hydroborates and a related separated ion pair

    Sarazin, YannCarpentier, Jean-FrancoisChapple, Peter M.Roisnel, Thierry...
    7页
    查看更多>>摘要：The syntheses and characterisation of two molecular barium-hydroborate complexes supported by a bulky bis (imino)carbazolate ligand, namely [{Carb(Dipp)}Ba(mu-H(2)Bpin)](3) (2(3)) and [{Carb(Dip)p}Ba(H-2-9BBN).Et2O] (3.Et2O), are presented. These two complexes are obtained in high yields upon reaction of the amido precursor [{Carb(Dipp)} BaN(SiMe3)(2)] (1) with the commercially available pinacolborane or [H-9BBN]2, respectively. The solid-state molecular structures of the complexes were solved, and show 23 to form a solvent-free cyclic trimer, whereas the monomeric 3.Et2O is solvated by one molecule of diethyl ether. Furthermore, the well-defined ion pair [{Carb(Dipp)}Ba.(Et2O)(2)]+[H2N{B(C6F5)(3)}(2)]- (4), a rare occurrence of soluble barium cation, was also obtained in good yield upon treatment of 1 with Bochmann's acid. Its X-ray structure was solved and reveals the absence of interaction between the metal cation and its counter-ion. Finally, the structure of the seven-coordinated, dicationic [Ba.(thf)(7)](2+)[H2N{B(C6F5)(3)}(2)](2)(-) (5) is also presented.
      原文链接:
    • NSTL
    • Elsevier

    Iron(II), cobalt(II), and nickel(II) complexes with 1,10-phenanthroline and 2,2'-bipyridyl and the macropolyhedral borane cluster [trans-B20H18](2-) as counterion

    Avdeeva, Varvara V.Kubasov, Aleksey S.Korolenko, Svetlana E.Privalov, Viktor I....
    8页
    查看更多>>摘要：The iron(II), cobalt(II), and nickel(II) complexation with 1,10-phenanthroline (Phen) and 2,2'-bipyridyl (Bipy) have been studied in the presence of the [B20H18](2-) anion. Tris-chelate metal complexes [ML3][B20H18] (M = Fe, L = Bipy (1), Phen (2); M = Co, L = Bipy (3), Phen (4); M = Ni, L = Bipy (5), Phen (6)) have been isolated and characterized by elemental analysis, IR and 11B NMR spectroscopy. It has been found that the composition of nickel(II) and iron(II) complexes with Bipy and Phen and cobalt(II) complex with Bipy could not be changed by varying the ratio of reagents; tris-chelate compounds were isolated when the M: L ratio was equal to 1: 1, 1: 2, and 1: 3 (except for cobalt(II) and Phen). For cobalt, it was found that when the Co: Phen ratio is equal to 2: 1, binuclear cobalt(II) complex [Co-2(Phen)(4)Cl-2][B20H18] (8) was formed. Binuclear complex 8 dissociates in DMF, and mononuclear cobalt(II) complex [Co(Phen)(2)Cl(DMF)]2[B20H18] (9) was isolated. The structures of compounds 1 center dot Bipy center dot 2CH(3)CN, 4 center dot 4CH(3)CN, 4 center dot 5CH3CN, 6 center dot 2DMF, 8 center dot CH3CN and 9.2DMF have been determined by X-ray diffraction.
      原文链接:
    • NSTL
    • Elsevier

    Antidiabetes, antimicrobial and antioxidant studies of mixed beta-diketone and diimine copper(II) complexes

    Omoregie, Helen O.Yusuf, Tunde L.Oladipo, Segun D.Olofinsan, Kolawole A....
    11页
    查看更多>>摘要：A series of copper(II) complexes, [Cu(dbm)(phen)NO3](1), [Cu(dbm)(bipy)NO3](2), [Cu(dbm)(phen)Br](3), [Cu (dbm)(bipy)Br](4), [Cu(dbm)(phen)Cl](5), and [Cu(dbm)(bipy)Cl](6) where dbmH = dibenzoylmethane, bipy = 2,2'-bipyridine and phen = 1,10-phenonthroline have been synthesized and characterized by elemental analysis, molar conductance, magnetic susceptibility, FT-IR and UV-Visible spectroscopies. The crystal structures of complexes 4, 5 and 6 revealed that the geometry around the copper(II) centre is distorted square pyramidal. In this coordination manner, the copper(II) centre bound to two oxygen atoms from dbmH, two nitrogen atoms from the co-ligand (phen or bipy), and also to a counter ion (NO3- or Cl- or Br-). The molar conductivity measurement in nitromethane displayed a Lambda(m) value of 14-55 Omega(- 1) cm(2) mole(-1), which confirms that they are non electrolyte. The antimicrobial, antidiabetic studies and antioxidant properties for all six complexes were also evaluated. All the complexes showed moderate to good antibacterial activities against E. coli, P. aeruginosa, S. aureus, and B. subtillis. Complex 5 was observed to be more active than ciprofloxacin against all the tested bacteria. Antidiabetes properties of the complexes were also investigated using alpha-glucosidase and alpha-amylase assay. Complex 5 had 27 mu M and > 1000 mu M while the reference drug, acarbose, had 28 mu M and 948 mu M for alpha-glucosidase and alpha-amylase inhibition, respectively. Complex 5 with the lowest IC50 value of 437 mu M showed the highest NO center dot scavenging activity than other complexes and even gallic acid with IC50 values of 457 mu M (standard drug). However, all the complexes showed poor free radical scavenging ability. Density functional theory was used to determine the appropriate geometries and electronic properties of complexes 4, 5 and 6 at the atomic level.
      原文链接:
    • NSTL
    • Elsevier

    Synthesis and photoluminescence characterization of the complexes of samarium dibenzoylmethanates with 1,10-phenanthroline derivatives

    Nehra, KapeeshaDalal, AnujHooda, AnjliSaini, Raman Kumar...
    7页
    查看更多>>摘要：The eight coordinated complexes of samarium were synthesized with dibenzoylmethane (DBM) and bidentate auxiliary ligand. Ternary complexes of samarium of the type [Sm(DBM)3L] (L = 1,10-Phenanthroline or its derivatives) were prepared by one step method. These complexes were characterized by spectroscopic techniques and thermo-gravimetric analysis. The proton-NMR data of all the complexes are reliable with the coordination of three DBM units and one neutral unit. Luminescence spectra of the complexes taken in powdered form, illustrate the bright red luminescence at 648 nm upon UV excitation that is accredited to the 4G5/2 -> 6H9/2 transition of Sm3+ ion. The domination of hypersensitive transition corresponding to 648 nm reflects the asymmetric environment around samarium ion and their intensity undergoes significant change on variation in the binding environment about metal ion. The intense luminescence and color coordinates demonstrate that the complexes might be used as promising candidate in displays and light emitting devices.
      原文链接:
    • NSTL
    • Elsevier

    Design of molecular magnetic materials based on a new family of mixed-lanthanide Co-Ln clusters by the use of the 1,3-Bis[tris (hydroxymethyl)-methylamino]propane ligand

    Liu, YingyingShi, DandanXu, Feng
    8页
    查看更多>>摘要：A new family of tetranuclear Co-Ln clusters, including both single and mixed-lanthanides, was synthesized by the use of a bis-tris propane ligand. Our studies showed that although single-lanthanide {Co3Ln} compounds assembled from lanthanide elements heavier than Nd are not accessible, mixed-lanthanide analogues retaining the original structure can be obtained. An array of magnetic measurements was used to reveal the single-molecule magnet behaviors and magnetocaloric effect of Co-Ce/Dy and Co-Ce/Gd clusters, respectively. Thus, this study may open up new avenues for the design of molecular magnetic materials by synthesizing mixed-lanthanide 3d-4f clusters.
      原文链接:
    • NSTL
    • Elsevier

    A New Organic-Inorganic Hybrid Compound: Synthesis, crystal structure, Hirshfeld surface analysis, vibrational, optical, magnetic properties and theoretical study

    Kaiba, A.Geesi, Mohammed H.Guionneau, P.
    11页
    查看更多>>摘要：Renewable technologies represent a solution to reduce the energy demand and dependency on fossil fuels. Here, attention is focused on organic inorganic hybrids used in photovoltaic. The present work is the investigation of a new organic-inorganic hybrid C4H10Cl3NO2Sn that crystallizes in a monoclinic system with C2/c space group and unit cell parameters (a = 32.071(5) angstrom, b = 5.827(5) angstrom, c = 11.596(5) angstrom, beta = 94.858(5)degrees, and Z = 4) at room temperature. The crystal structure exploration reveal the stabilization of the crystal packing is carried out by a complex network of hydrogen interactions that lead formation of layered organic-inorganic hybrid stacked along the a-axis. The intermolecular interactions were elucidated by Hirchfeld surface analysis and fingerprint plots. The vibration modes were probed by Micro-Raman spectroscopy. Also, the vibrating sample magnetometer (VSM) measurement shows the ferromagnetism aspect of the compound as well as the energy gap was estimated from UV-visible absorption spectroscopy.
      原文链接:
    • NSTL
    • Elsevier