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In this paper, a Sm(III) cluster-based 2D coordination polymer {[Sm(2-stp)·3(H2O)]·(H2O)}n, (where 2-stp = 2-sulfoterephthalate), 1 has been synthesized hydrothermally and doped into poly(methyl methacrylate (PMMA) fibers through electrospinning technique to get a new 1D luminescent composite fibers, Sm/PMMA. The crystal structure of Sm(III) complex has been determined by single crystal X-ray diffraction measurements. Sm/PMMA composite fibers have been characterized by field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), photoluminescence spectroscopy (PL), and thermogravimetric analysis (TGA) in comparison to that of the pure Sm(III) complex. The luminescent spectra of the composite nanofibers (Sm/PMMA) has demonstrated strong characteristic emission of Sm(III) ions and has also pointed out much better thermal stability than the pure Sm(III) complex.

KARA, Hulya/0000-0002-2032-8930 WOS: 000513242600009 Two new Er(III)-cluster-based coordination compounds have been synthesized by hydrothermal technique using monosodium 2-sulfoterephthalate (2-stp) and 4,4 '-bipyridyl (4,4 '-bpy) ligands. Depending on synthetic procedure, monomeric and polymeric Er(III) products, isolated as {[Er(2-stp)(2)(H2O)(6)]0.2(4,4 '-bipy)0.4(H2O)}, 1 and {[Er(2-stp)(4,4 '-bipy)(H2O)](H2O)}(n), 2. Both compounds have been characterized by elemental analysis, FT-IR, UV-visible and single-crystal X-ray diffraction and solid-state photoluminescence. The X-ray structure analyses show that Er atom is surrounded by two 2-stp ligands which have monodentate connection mode forming a monomeric structure in compound 1. However, in compound 2, Er atoms are coordinated by four bridging 2-stp ligands which adopt a hexadentate connection mode to form a central symmetrically dimeric building unit. The photoluminescence spectrums of the compounds have been exhibited intense blue emission for 1 and cyan-blue emission for 2. The band observed in NIR region at 1532 nm (for 1) and 1540 nm (for 2) are the typical Er-III emission. The excellent NIR luminescent properties, indicating their promising potential applications as gain medium materials in optical amplification devices.

WOS: 000529723700002 As a new generation fire-resistant material, the intumescent coating has significant advantages over conventional fire protection materials. The applications of the intumescent coating have changed widely and have dominated the fire engineering market. In this study, intumescent coatings with different nanosized additives such as fumed silica, organo-montmorillonite, aluminum oxide and titanium dioxide were investigated. It was shown that organically modified montmorillonite and hydrophobized silica reduced fire resistance properties of intumescent coatings. The reason for such decrease is the shift of the expansion processes to higher temperatures. This phenomenon increases the time of direct heating of the substrate. Moreover, it was established that the minor concentrations of organically modified montmorillonite could significantly change the structure of coatings and increase the specific heat insulation properties of the carbon foams. Such an effect was also observed in the case of the use of hydrophobic silica, but to a lesser extent. It was shown that nanosized additives have effect on the expansion factor and the foam structure. It was suggested that this effect could be explained by the complex influence of the nanoparticles on the bubble growth processes through the melt viscosity modification. Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [2221] The authors are grateful to the 7th International Conference "Nanotechnologies and Nanomaterials" NANO-2019 for creating an ambience of friendship and for giving the opportunity to present our research. Dr. Raks and Dr. Kara would like to thank The Scientific and Technological Research Council of Turkey (for the 2221-Fellowships for Visiting Scientists and Scientists on Sabbatical Leave) and Molecular Nano-Materials Research Group, Department of Physics and Faculty of Science (Mugla Stk Kocman University) for their hospitality.

0000-0002-2032-8930 WOS: 000446704800030 A new Er3+-cluster-based 2D coordination polymer with the formula {[Er(SSA)(H2O)(2)](H2O)}(n) (SSA = 5- sulfosalicylic acid), complex 1, has been successfully synthesized via hydrothermal method and structurally characterized by elemental analysis, FT-IR, UV, single crystal and powder X-ray diffraction. Complex 1 reveals the Erbium atom is coordinated to eight oxygen atoms by four symmetry-related SSA ligands and two coordinated water molecules to form a distorted square-antiprismatic geometry. The photoluminescence spectrum of the complex 1 display intense pink emission with CIE chromaticity coordinates (0.540, 0.250). The complex 1 emit NIR luminescence at 1535 nm, which corresponds to the I-4(13/2)-I-4(15/2) transition of Er3+ ion. Moreover, its full width at half maximum values is 113 nm. This complex can potentially be applied to polymeric erbium-doped optical amplifiers, planar waveguides or infrared OLEDs. Research Funds of Mugla Sitki Kocman University [BAP-2016/52]; Dokuz Eylul UniversityDokuz Eylul University [2010.KB.FEN.13] The authors are grateful to the Research Funds of Mugla Sitki Kocman University (BAP-2016/52) for the financial support, Dokuz Eylul University for the use of the Agilent Xcalibur Eos diffractometer (purchased under University Research Grant No. 2010.KB.FEN.13) and Balikesir University, Science and Technology Application and Research Center (BUBTAM) for the use of the Photoluminescence Spectrometer.

0000-0002-2032-8930 WOS: 000446704800003 A new tetranuclear cyanide-bridged Mn-III-Fe-III complex based on manganese(III) Schiff base and hexacyanoferrate(III) units, [Mn(L)(MeOH)(2)][{Mn(L)}{Fe(CN)(6)}{Mn(L)(MeOH)}]center dot 2MeOH, [H2L=N,N'-bis(2-hydroxy-1-naphthalidenato)-1,2-diaminopropane] (1), has been synthesized and characterized by elemental analysis, UV-Vis, FT-IR, PXRD, single crystal X-ray analyses, magnetic and photoluminescence measurements. Complex 1 consist of one trinuclear cyanido-bridged anion, in which [Fe(CN)(6)](3-) anion bridge [Mn(L)](+) and Mn(L)(MeOH)}](+) cations via two C equivalent to N groups in the cis positions, and also one isolated manganese [Mn(L)(MeOH)(2)](+) cation. DC magnetic susceptibility and magnetization studies showed that complex 1 indicates an antiferromagnetic coupling between low-spin Fe(III) and high-spin Mn(III) through the cyanide bridges. In addition, the complex 1 displays a strong cyan-blue luminescence emission in the solid state condition at room temperature. This behavior might be seen easily from the chromaticity diagram. Thus, the complex may be a good promising cyan-blue OLED developing electroluminescent materials for flatted or curved panel display applications due to the fact that it has such features. Research Funds of Mula Stk Kocman University [BAP-2018/008] The authors are grateful to the Research Funds of Mula Stk Kocman University (BAP-2018/008) for the financial support and Balikesir University, Science and Technology Application and Research Center (BUBTAM) for the use of the Photoluminescence Spectrometer. The authors are also very grateful to Prof. Dr. Andrea Caneschi (Laboratory of Molecular Magnetism, Department of Chemistry, University of Florence) for the use of SQUID magnetometer and helpful suggestions.

A new chloride bridged polymeric Cu(II) complex, [Cu(HL)(μ-Cl).H2O]n, 1, (H2L = 2,4-dichloro-6-{[(2-hydroxyethyl)imino]methyl}phenol) has been synthesized and characterized by elemental-spectral an...

A new defect dicubane cobalt(II)/cobalt(III), [(CoII2CoIII2L42(H2O)(CH3COO)(CH3COOH]. 4H2O complex (1) where H2L = [1–(3–hydroxypropyliminomethyl)naphthalene–2–ol], has been synthesized and characterized by element analysis, FT–IR, solid UV–Vis spectroscopy and single crystal X–ray diffraction. The crystal structure determination shows a cationic tetrameric arrangement consisting of a defect dicubane core with two missing vertexes. Each cobalt ion has a distorted octahedral geometry with six coordinate ordered CoII and CoIII ions. The solid state photoluminescence properties of complex (1) and its ligand H2L have been investigated under UV light at 349 nm in the visible region. H2L exhibits blue emission while complex (1) shows red emission at room temperature. Variable–temperature magnetic susceptibility measurements on the complex (1) in the range 2–300 K indicate an antiferromagnetic interaction.

0000-0002-2032-8930 WOS: 000416568000019 In the current work, a new coordination complex, [Cu(HL)(2)], 1 [H2L = 2-((E)-(2-hydroxypropylimino) methyl)-4-nitrophenol] was successfully synthesized and characterized by IR, UV-vis and photoluminescence spectroscopic techniques, single crystal and powder X-ray diffraction measurements. In the crystalline structure of complex 1, the aliphatic -OH group of the ligand is not coordinated and points away from the metal coordination zone, and also actively participates in intermolecular bifurcated O-H center dot center dot center dot O hydrogen bonds which link the molecules to form hydrogen-bonded linear chains. C-H center dot center dot center dot pi and pi center dot center dot center dot pi contacts also connect the molecules in the structure which form to 3D structure. This hydrogen bonded polymeric networks lie in the bc-plane and stacks along to the a-axis. Furthermore, complex 1 and its ligand H2L display an intense navy-blue emission and blue emission in the solid state at room temperature, respectively, when they are excited under UV light. Mugla Sitki Kocman University Research Projects Coordination OfficeMugla Sitki Kocman University [BAP-2016/052] The authors are grateful to Mugla Sitki Kocman University Research Projects Coordination Office (BAP-2016/052) for the financial support. The authors also acknowledge to Balikesir University, Science and Technology Application and Research Center (BUBTAM) for the use of the Photoluminescence Spectrometer.

Kara, Hülya (Balikesir Author), Three Schiff base ligands were synthesized via condensation between 2,6-diformyl-4-R-phenol [where R = tert-butyl (HL1), iso-propyl (HL2), and chloro (HL3)] and N,N-dimethylethylene-1,2-diamine to prepare a series of copper(ii) complexes. [Cu-2(L-1)(OH)(ClO4)](ClO4) (1) and [Cu-2(L-1)(SCN)(3)] (2) were synthesized from HL1, whereas [Cu-2(L-2)(SCN)(2)](ClO4) (3) and [Cu-2(L-3)(N-3)(ClO4)](ClO4) (4) were obtained from the ligands HL2 and HL3, respectively. All the complexes were characterized by the usual physico-chemical techniques (FT-IR, UV-vis, single-crystal XRD, ESI-MS, H-1 NMR and EPR) and their variable temperature magnetic study was also carried out. Single-crystal XRD analysis proved that a phenoxyl bridge was present in all four complexes. Complexes 1 and 4 contained additional bridges as hydroxo and mu(1,1)-azido ligands, respectively, together with perchlorate species to generate new binuclear Cu-II complexes containing a triple-mixed bridge. Complex 2 formed a thiocyanate-bridged polymeric chain. Interestingly, a polymeric chain was also formed via the participation of perchlorate ions in the case of complex 3 although thiocyanate, a better bridging anion, was present as a pending co-ligand. The influence of the 'auxiliary part' of the ligands, i.e., the 'R' group towards the structural diversity of complexes 1-4 was evaluated with the help of a DFT study. A magnetic study revealed the fact that the copper centres were antiferromagnetically coupled in all four complexes. The catecholase activities of all four complexes were determined in a DMSO medium and complex 4 was found to be inactive. The order of the catecholase activity of the remaining three complexes was 1 < 2 approximate to 3. The trend of the catecholase activity was explained with the help of an ESI-MS study., Council of Scientific & Industrial Research (CSIR) - India - (09/028.1023)/2018-EMR-I Department of Science & Technology (India) - 327(sanc)/ST/P/S&T/15G-8/2016 dt 09/11/2016

A new linear trinuclear MnIII-MnII-MnIII complex 1 has been synthesized and characterized by elemental, spectral, X-ray and magnetic analysis. X-ray diffraction studies show that the central MnII ion is located at a crystallographic inversion center and is triply bridged to the terminal MnIII ions through one methoxide, one syn-syn carboxylate and one hydroxyl oxygen bridges with the short MnIII…MnII distance that is 3.047 A. The intermolecular C-H…O, C-H…π and ring-metal interactions are observed in the hydrogen-bonded assembly of 1. Magnetic studies reveal that the mixed-valence complex 1 has S = 3/2 ground state with antiferromagnetic exchange interactions between MnII and MnIII ions.

Two Schiff base complexes, [Cu(HL)2], 1 and [Ni(HL)2], 2 [H2L = 2–((E)–(2–hydroxyethylimino)methyl)–1–naptaphenol] have been synthesized and characterized by elemental analysis, 1H NMR, 13C NMR, IR spectroscopy, and X-ray diffraction. In the crystalline architecture of 1 and 2, intermolecular O−H···O hydrogen bonds link the molecules which form one-dimensional polymeric chain structure along the c axis. C−H···O and C−H···π intermolecular interaction also connect the molecules in the structures which form to 3D structures of 1 and 2. The ligand and metal complexes 1 and 2 were screened for antibacterial and antifungal activities.

Schiff base–metal complexes have been used widely as catalysts for many organic reactions, such as ring-opening polymerization and oxidation. In view of the importance of CdIIcoordination polymers and in an effort to enlarge the library of such complexes, the title novel polymeric CdIItridentate Schiff base complex, [Cd3(C13H16BrN2O)2Cl4(CH4O)2]n, has been synthesized and characterized by elemental analyses, UV and IR spectroscopies, and single-crystal X-ray diffraction. The complex crystallizes in the triclinicP\overline{1} space group with two symmetry-independent CdIIatoms, one of which lies on an inversion centre, and analysis of the crystal structure shows that both CdIIatoms are six-coordinated; the environment around one CdIIatom can be described as distorted octahedral, while that around the second CdIIatom is octahedral. The CdIIatoms are linked by chloride ligands to form a one-dimensional coordination polymer. The nonbonding intermolecular Cd...Cd distances are 3.7009 (4) and 4.3563 (5) Å. Furthermore, the photoluminescence properties of the complex have been investigated and it displays a strong red emission in the solid state at room temperature.

Two new tetranuclear [Ni4(L1)4(MeOH)4] (1) and [Ni4(L2)4(EtOH)(MeOH)(H2O)2]·H2O (2) complexes have been synthesized by solvothermal method. We here report the spectroscopic, structural, photoluminescence and magnetic properties of both complexes. Complex 1 and 2 exhibit a cubane-like Ni4O4 structure. All Ni(II) center has a slightly distorted octahedral geometry. The optical properties of 1 and 2 have been analyzed by photoluminescence spectra obtained in the visible region. Variable-temperature (2–300 K) magnetic studies have been analyzed by using the Heisenberg Hamiltonian model with 2J exchange pathways. The best–fit parameters in analysis of the magnetic data are found as J1 = −2.38 cm−1, J2 = +5.43 cm−1, g = 2.2, Nα = 0.08 for 1, J1 = −2.34 cm−1, J2 = +4.90 cm−1, g = 2.2 and Nα = 0.11 for 2. These results are shown dominant ferromagnetic interactions between Ni(II) centers. Finally, the strong luminescence emission of both complexes makes them potentially useful photoactive material in developing optical and electronic materials.

Antibiotic resistance is one of the biggest health problems of the twenty-first century. In order to cope with this global problem, alternative preventive strategies such as quorum sensing interruption are needed. Therefore, it is very important to develop new compounds with anti-quorum sensing activity. Here we present the synthesis and structural characterization of two new Co (II) complexes; [Co(btmpp)(NCO)2], 1 and [Co(btmpp)(NCSe)2], 2 (where btmpp is: 2,6-bis(3,4,5-trimethylpyrazolyl)pyridine). The crystal structures of both complexes is determined using single-crystal X-ray diffraction. The coordination environment of Co(II) atoms can be described as a distorted square pyramidal geometry. Both complexes is screened for antibacterial activities against Gram-positive (B. substilis) and Gram-negative (P. aeruginosa, S. typhimurium, S. sonnei, Y. enterocolitica) bacterial strains. The effects of these complexes on QS-regulated behaviors of bacteria such as swarming, and biofilm formation is also examined. All bacteria are found to be more sensitive to complex 2 than complex 1.

0000-0002-2032-8930 WOS: 000430472900015 A new open-cubane Mn-III, [{(H2O)(MnL)-L-III}{(MnL)-L-III}](2)center dot 2(CH3OH).2(CH3CH2OH)center dot 2Cl, 1 where H (2) L=[N-(2-hydroxyethyl)-3-methoxysalicylaldimine] has been synthesized and characterized by element analysis, FT-IR, solid UV-Vis spectroscopy and single crystal X-ray diffraction. The crystal structure determination shows an open-cubane tetranuclear complex. The Mn1 (Mn1(i)) ions is hexacoordinate by NO5 donor sets while the Mn2 (Mn2(i)) is pentacoordinate by NO4 donor sets. The solid state photoluminescence properties of complex 1 and its ligand H (2) L have been investigated under UV light at 349 nm in the visible region. H (2) L exhibits blue emission while complex 1 shows orange-red emission at room temperature. Variable-temperature magnetic susceptibility measurements on the complex 1 in the range 2-300 K indicate an antiferromagnetic interaction. Balikesir UniversityBalikesir University [BAP-2017/200] The authors are grateful to the Research Funds of Balikesir University (BAP-2017/200) for the financial support and Balikesir University, Science and Technology Application and Research Center (BUBTAM) for the use of the Photoluminescence Spectrometer. The authors are also very grateful to Prof. Dr. Andrea Caneschi (Laboratory of Molecular Magnetism, Department of Chemistry, University of Florence) for the use of SQUID magnetometer and helpful suggestions.

0000-0002-2032-8930 WOS: 000446704800006 A new cubane-based cobalt(II) cluster, [Co4L4] (1), where H2L = 2-((E)-(2-hydroxyethylimino) methyl)-4-chlorophenol has been prepared using a solvothermal process and characterized by structural, optical and magnetism. The crystal structure of 1 consists of a tetranuclear Co4O4 core in an open-cubane framework. Each cobalt(II) ion is penta-coordinated in a distorted square pyramidal geometry (tau(Co1=Co1i) = 0.030, tau(Co2=Co2i) = 0.023). Furthermore, the photoluminescence analysis indicates that 1 has a strong blue emission which should be attributed to coordination of the metal to the ligand. The temperature dependence of the magnetic susceptibilities of 1 shows antiferromagnetic coupling (J= - 26.61 +/- 0.01) between cobalt(II) ions. Research Funds of Balikesir UniversityBalikesir University [BAP-2017/199] The authors are grateful to the Research Funds of Balikesir University (BAP-2017/199) for the financial support and Balikesir University, Science and Technology Application and Research Center (BUBTAM) for the use of the Photoluminescence Spectrometer. The authors are also very grateful to Prof. Dr. Andrea Caneschi (Laboratory of Molecular Magnetism, Department of Chemistry, University of Florence) for the use of SQUID magnetometer and helpful suggestions.

A new dinuclear Fe(III) complex, [Fe(5-MeOL1)(OH)0.86(CH3O)0.14]2•2(CH3OH), [H2-5-MeOL1 = N,N′-bis(5-methoxy-2-hydroxybenzylidene)-2,2-dimethylpropane-1,3-diamine], 1 has been synthesized and characterized by single crystal structure analysis. The structure of 1 consists of two Fe(III) centers with one tetradentate schiff base ligand (N2O2) which are bridged by dihydroxo/dimethoxo groups to yield a Fe2O2 core. Complex 1 exhibits weak antiferromagnetic exchange interaction between Fe(III) ions with J = −0.21 cm–1.

A series of new crystal structures of salts containing 3- and 4-pyridineboronic acid (3- and 4-pba) with chlorometallate have been prepared: [4-pbaH][MnCl2] (1), [4-pbaH][CdCl2], (2), [4-pbaH]2[CuCl4] (3), [4-pbaH]2[PdCl4] (4), [3-pbaH](2)[CdCl4] (5), [3-pbaH][CuCl3(OH2)] (6), and [3-pbaH][PdCl2] (7). In these salts five structural forms for the chlorometallate species are observed: mononuclear square planar [M = Pd (4 and 7)], dimeric square-pyramidal [M = Cu (3)], polymeric square-pyramidal [M = Cu (6)], polymeric trans-edge-sharing octahedral [M = Mn (1), Cd (2)], and polymeric cis-edge-sharing octahedral [M = Cd (5)]. The cyclic R2,2(8) boronic acid dimer is formed in the salt of 1-5. NH center dot center dot center dot Cl2M synthons A have been exploited in 1-4, 6, and 7. Both NH...Cl2M (sythons A) and B(OH)2 center dot center dot center dot Cl2M (sythons B) interactions give rise to a synthon of form I in 6. The uncommon folded conformation of the NH center dot center dot center dot Cl2M (synthons A) are formed in 7. The NH or OH donors and consequent branching of the NH center dot center dot center dot Cl hydrogen-bond network leads to one-, two-, and three-dimensional structures. These structures are further stabilized by CH center dot center dot center dot O and CH center dot center dot center dot Cl and p center dot center dot center dot p stacking interactions.

Two new heterodinuclear Schiff base complexes, [Hg(L)NiCl2(DMF)(2)] 1, and [Zn(L)NiCl2(DMF)(2)] 2, where H2L = N,N'-bis(salicylidene)-1,3-diaminopropane and DMF = dimethylformamide have been synthesized and characterized using elemental analysis, IR spectroscopy, thermal analysis and X-ray diffraction. Structural studies on 1 and 2 reveal the presence of a heterodinuclear [(NiHgII)-Hg-II] unit and [(ZnNiII)-Ni-II] in which the central metal ions are connected to each other by two phenolate oxygen bridges. For complex 1 the Ni(II) ion adopts an elongated octahedral geometry (NiN2O4) while the Hg(II) ion assumes a distorted tetrahedral arrangement (HgO2Cl2) whereas for complex 2 the Zn(II) ion adopts an elongated octahedral geometry (ZnN2O4) while the Ni(II) ion assumes a distorted tetrahedral arrangement (NiO2Cl2). There are intermolecular C-H center dot center dot center dot Cl-M interactions among the dinuclear complexes which are interconnected for 1 and 2. These intermolecular interactions result in the formation of a three dimensional structure for 1 and one dimensional zig-zag chains for 2. (C) 2014 Elsevier B.V. All rights reserved.

[Fe(SB)(H2O)]ClO4 and [NEt4]3[Fe(CN)6] react in methanol to give a cis cyano-bridged assembly, 3D [NEt4][Fe(5-ClL1)]2[Fe(CN)6] (5-ClL1H2 = N,N′-bis(5-chlorosalicylidenato)-2,2-dimethyl-1,3-diaminopropane), 1, and a trans cyano-bridged trinuclear complex, [NEt4][Fe(5-ClL2)(MeOH)]2[Fe(CN)6] (5-ClL2H2 = N,N′-bis(5-chlorosalicylidenato)-1,2-diaminopropane), 2, depending on the Schiff base used. Complexes 1 and 2 have been characterized by X-ray analyses and magnetic measurements. The four CN− in the equatorial plane of the [Fe(CN)6]3− moiety bridge four Fe ions each in the cis position, which results in a 3D neutral layered structure giving a [–Fe–NC–Fe–CN–Fe–] linkage for 1. The two CN− in the equatorial plane of the [Fe(CN)6]3− moiety bridge two Fe ions, in the trans position, which results in a hydrogen bonded 2D neutral layered structure for 2. Magnetic studies reveal that complex 1 exhibits weak intralayer ferromagnetic coupling, while complex 2 displays transition to a 3D ferromagnetic order between low-spin Fe(III) and high-spin Fe(III) through the cyanide bridges. Complex 2 further displays frequency-dependent alternating current magnetic susceptibility.

A new double end-on azide-bridged dinuclear nickel(II) Schiff base complex, [Ni-2(mu(1,1)-N-3)(2)(HL)(2)(MeOH)(2)], [HL = 2-[(2-hydroxypropylimino)methyl)-3,5-chlorophenoll has been synthesized and characterized by elemental analysis, UV and IR spectroscopy, single crystal X-ray diffraction, magnetic and photoluminescence study. The asymmetric unit contains half of the dinuclear unit. The Ni(HL) units in each dinuclear molecule are connected to each other by two bridging end-on azide ligands. In the crystalline architecture of the Ni(II) complex, intermolecular O-H center dot center dot center dot N hydrogen bonds link the molecules which form one-dimensional structure. Additionally, low temperature magnetic measurements indicate a dominant intradimer ferromagnetic interactions in double end-on azide-bridged dinuclear Ni(II) complex. Room temperature solid state photoluminescence measurements of Ni(II) complex show strong green emission band at lambda(max) = 508 nm while its free ligand H2L shows broad yellow emission band at lambda(max) = 594 nm. The luminescent performances making Ni(II) complex may be good candidates for potential luminescence materials. (C) 2017 Elsevier B.V. All rights reserved.

Copper(II)-Schiff base complexes have attracted extensive interest due to their structural, electronic, magnetic and luminescence properties. The title novel monomeric Cu

0000-0002-2032-8930 WOS: 000404578800016 Two coordination polymers, {[Ln(2-stp)(4,4 '-bipy)(H2O)]center dot(H2O)}, [Ln = Dy (1) and Eu (2), 2-stp = 2-sulfoterephthalate and 4,4 '-bipy = 4,4 '-bipyridine] have been characterized by solid state UV-vis, FTIR spectra, X-ray single crystal diffraction and solid state photoluminescence. Variable-temperature magnetic susceptibility and isothermal magnetization as function of external magnetic field is also studied for both complexes. After ligand-mediated excitation, both complexes show the characteristic visible and NIR luminescence of the corresponding Ln(III) ions (Ln = Dy, Eu) which is due to efficient energy transfer from the ligands to the central Ln(III) ions via an antenna effect. The indirect energy transfer in both complexes has been investigated and discussed in detail. Research Funds of Balikesir UniversityBalikesir University [BAP-2015/128]; Mugla Sitki Kocman UniversityMugla Sitki Kocman University [BAP-2017/035] The authors are grateful to the Research Funds of Balikesir University (BAP-2015/128) and Mugla Sitki Kocman University (BAP-2017/035) for the financial support.

Çoban, Mustafa Burak (Balikesir Author), Copper(II)-Schiff base complexes have attracted extensive interest due to their structural, electronic, magnetic and luminescence properties. The title novel monomeric CuII complex, [Cu(C10H11N2O4)2], has been synthesized by the reaction of 3-{[(3-hydroxypropyl)imino]methyl}-4-nitrophenol (H2L) and copper(II) acetate monohydrate in methanol, and was characterized by elemental analysis, UV and IR spectroscopies, single-crystal X-ray diffraction analysis and a photoluminescence study. The CuII atom is located on a centre of inversion and is coordinated by two imine N atoms, two phenoxy O atoms in a mutual trans disposition and two hydroxy O atoms in axial positions, forming an elongated octahedral geometry. In the crystal, intermolecular O - H...O hydrogen bonds link the molecules to form a one-dimensional chain structure and π-π contacts also connect the molecules to form a three-dimensional structure. The solid-state photoluminescence properties of the complex and free H2L have been investigated at room temperature in the visible region. When the complex and H2L are excited under UV light at 349?nm, the complex displays a strong green emission at 520?nm and H2L displays a blue emission at 480?nm.In a new monomeric CuII complex with 3-{[(3-hydroxypropyl)imino]methyl}-4-nitrophenolate ligands, intermolecular O - H...O hydrogen bonds link the molecules to form a one-dimensional chain structure and π-π contacts also connect the molecules to form a three-dimensional structure. The complex displays a strong green photoluminescence emission at 520?nm.

Hydrothermal reactions of lanthanide metal salts with 2-sulfoterephthalate (2-stp) and 4,4'-bipyridine (4,4'-bipy) led to three coordination polymers, {[Ln(2-stp)(4,4'-bipy)(H2O)]center dot(H2O)), [Ln = Gd (1), Ho (2) and Sm (3)]. Their structures have been established by X-ray single crystal diffraction. Complexes 1-3 are isostructural with 2D framework in which all Ln(III) atoms are nine-coordinated. All these 2D layers are further interlinked via hydrogen bonds resulting in 3D architecture. The solid-state photoluminescence measurements display the characteristic luminescence of Ho (2) and Sm (3), which is due to efficient energy transfer from the ligands to the central Ln(III) ions via an "antenna effect". Variable temperature magnetic susceptibility and isothermal magnetization as function of external magnetic field for 1-3 is studied which reveal mainly the presence of antiferromagnetic interactions and the thermal depopulation of Stark sublevels together with crystal field affects. (C) 2016 Elsevier B.V. All rights reserved.

Two pentanuclear NiII complexes, [Ni5(L1)2(CH3COO)6(OH)2(MeOH)2] (1) and [Ni5(L2)2(CH3COO)6(OH)2(H2O)2] (2), and one tetranuclear CuII complex, [Cu4(L3)2(CH3COO)4(O)] (3), have been synthesized from phenol-based “end-off” compartmental ligands HL1 to HL3 {HL1 = 2,6-bis[ethyl(2-thienyl)iminomethyl]-4-tert-butylphenol; HL2 = 2,6-bis[ethyl(2-thienyl)iminomethyl]-4-chlorophenol and HL3 = 2,6-bis[ethyl(2-thienyl)iminomethyl]-4-methylphenol, respectively}. The complexes have been structurally characterized and their magnetic properties have been investigated within the temperature range 2.2–300 K. Complexes 1 and 2 comprise two dinuclear [Ni2L2] units linked to a central Ni ion by bridging μ3-hydroxo groups. The cluster is stabilized by syn-syn-μ1,3-bridging and μ1,1,3-bridging acetate anions. The structural analysis of 3 revealed two crystallographically independent complexes that consisted of a tetrahedron of CuII ions connected to a central μ4-oxo species and further bridged by four acetate groups along four of the six edges of the Cu4 core. The other two edges are occupied by μ-phenoxo bridges from the deprotonated L3 ligand. Magnetic investigations revealed both ferromagnetic and antiferromagnetic interactions in 1 and 2 with single-ion zero-field splitting of magnitude comparable to exchange interactions, and strong antiferromagnetic interactions in 3.

Two alkoxo-bridged copper(II) tridentate Schiff base complexes [{Cu(H2L1)}4] (1) [H2L1 = N-(2-hydroxyethyl)-3,5-di-tert-butylsalicylaldimine] and {Cu(H2L2)}4 (2) [H2L2 = N-(2-hydroxyethyl)-4-methoxysalicylaldimine] have been synthesized and structurally and magnetically characterized. X-ray diffraction studies show that 1 and 2 are tetranuclear alkoxo-bridged copper(II) complexes that contain a rather distorted Cu4O4 cubane core of 4+2 type (four short and two long Cu···Cu distances). The coordination of each copper ion can be described as a distorted square pyramid with one nitrogen and four oxygen atoms from three ligands. Variable-temperature magnetic susceptibility measurements on the two tetranuclear complexes 1 and 2 in the range 2–300 K indicate ferromagnetic exchange coupling between copper(II) centers. The magnetic susceptibility data were analyzed by using a simple two-J model with J′ and J″ representing the magnetic exchange couplings through the short and long Cu···Cu exchange pathways, respectively. The J values were as follows: J′ = +28.7 cm–1 and J″ = +7.8 cm–1 for 1, and J′ = +39.8 cm–1 and J″ = +10.2 cm–1 for 2. The sign and magnitude of the exchange coupling constants were justified on the basis of the structural geometric factors of the bridging Cu(O)2Cu fragments, the overlap of the magnetic orbitals, and DFT calculations.

Çoban, Mustafa Burak (Balikesir Author), In this study, the synthesis, X-ray crystal structure and magnetic properties of a new hexanuclear Fe(III) complex, 2[OFe6(thme)(4)Cl-6].4[C6H15N].6[H2O] (1), (H(3)thme = 1,1,1-Tris(hydroxymethyl)ethane) is reported. The structure of 1 is described as the hexametalate core [OFe6(thme)(4)Cl-6] consisting of an octahedral arrangement by four alkoxo oxygen atom from thme ligand, a terminal chloride atom and one mu(6)-oxo group at the center. Variable-temperature magnetic susceptibility measurements of 1 indicate an antiferromagnetic interaction between the Fe(III) centers.

Two novel binuclear Mn(III) [C22H26Cl4Mn2N2O6] (1) and Cu(II) [C26H14Cl4Cu2N2O4] (2) Schiff base complexes have been synthesized and their crystal structures have been determined by single crystal X-ray diffraction analysis. Structural analysis of (1) and (2) shows that the Schiff base ligand of dimers coordinates toward one metal atom in a tridentate mode and each Mn atom is six-coordinated while each Cu atom is four-coordinated. The two halves of the dimers are related by a crystallographic inversion center. The intramolecular non-bonding Mn⋯Mn separation is 2.994 A for complex (1) and Cu⋯Cu separation is 2.994 A for complex (2). Magnetic susceptibilities for (1) and (2) in the solid state have been measured over the temperature range 2–350 K as a function of temperature and the magnetic parameters have been determined with fitting procedure. Magnetic measurements on (1) and (2) reveal the presence of antiferromagnetic spin–exchange interactions between the transition metal ions.

Schiff base-metal complexes have been used widely as catalysts for many organic reactions, such as ring-opening polymerization and oxidation. In view of the importance of Cd(II) coordination polymers and in an effort to enlarge the library of such complexes, the title novel polymeric Cd(II) tridentate Schiff base complex, [Cd3(C13H16BrN2O)2Cl4(CH4O)2]n, has been synthesized and characterized by elemental analyses, UV and IR spectroscopies, and single-crystal X-ray diffraction. The complex crystallizes in the triclinic P-1 space group with two symmetry-independent Cd(II) atoms, one of which lies on an inversion centre, and analysis of the crystal structure shows that both Cd(II) atoms are six-coordinated; the environment around one Cd(II) atom can be described as distorted octahedral, while that around the second Cd(II) atom is octahedral. The Cd(II) atoms are linked by chloride ligands to form a one-dimensional coordination polymer. The nonbonding intermolecular Cd...Cd distances are 3.7009 (4) and 4.3563 (5) Å. Furthermore, the photoluminescence properties of the complex have been investigated and it displays a strong red emission in the solid state at room temperature.

Çoban, Mustafa Burak (Balikesir Author), A trinuclear cyanide-bridged Mn-III-Fe-III compound, [NEt4][Mn(3,5-ClL)(2)(MeOH)](2)Fe(CN)(6)], [3,5-ClLH2 = N, N'-bis(3,5-chlorosalicylidenato)-1,2-diamino propane)], 1, has been characterized by X-ray analyses, magnetic and photoluminescence measurements. The structure assumes a two-dimensional network consisting of Mn-NC-Fe-CN-Mn (Fe1-C19-N4 = 175.9(3)degrees, C19-N4-Mn1 = 145.5 (3)degrees). The magnetic properties of this compound indicate antiferromagnetic coupling between low-spin Fe(III) and high-spin Mn(III) through the cyanide bridges. Furthermore, solid state photoluminescence properties of complex 1 have been investigated at room temperature.

Kara, Hülya (Balikesir Author), Six N, N, O-donor Schiff-base ligands, HL1-HL6, [HL1/HL2/HL3= {2-(2-piperazin-1-yl) ethylimino) methyl)-4-(Cl/H/Me)-phenol}; HL4/HL5/HL6={2-(2-morpholine/piperidine/pyrrolidine 1-yl) ethylimino) methyl)-4-chlorophenol}, have been designed by combining 5-R-2-hydroxy-benzaldehyde, (R= Cl/H/Me) and N-(2-aminoethyl)- Y,(Y=piperazin/morpholine/piperidine/pyrrolidine) with the view to explore the role of R and X (part of Y excluding coordinating N) on the coordination chemistry of Cu (II) in presence of bromide as counter anion. HL1-HL6 formed in situ on reaction with Cu(II) Br-2 produce complexes 1-6, re-spectively. Complex 1, [Cu(II)(2)Cu(I)(2)(L1)(MeOH)(2)Br-7.30], is a mixed valence Cu(I)-Cu(II) species having phenyl ring brominated at ortho position with 0.65 occupancy. Complexes 2-4 are mononuclear species with general formula [Cu{L2/L3/L4)} Br2]. Complexes [Cu-3(L5)Br-4] (5) and [Cu-3(L6) Br-4] (6) are trinuclear species having similar structure but exhibit different magnetic property, 5 is ferro-(J= + 16.64 cm(-1)) and 6 is antiferromegnetic (J= -11.76 cm (-1)). The influence of R and X on bromonation, magnetic property and nuclearity issues have been rationalized by DFT calculations., MINECO of Spain CSD2010-0065 UGC/729/Jr Fellow(Sc) UGC, India

N-(p-benzoyl)-anthranilic acid (BAA) derivatives have been synthesized with different substituents (X: Br, Cl, OCH3, CH3), and their crystal structures have been analyzed in order to understand the variations in their molecular geometries with respect to the substituents by using H-1 NMR, C-13 NMR, IR and X-ray single-crystal diffraction. The carboxylic acid group forms classic O-H center dot center dot center dot O hydrogen bonded dimers in a centrosymmetric R-2(2)(8) ring motifs for BAA-Br and BAA-Cl. However, no carboxylic add group forms classic O-H center dot center dot center dot O hydrogen bonded dimers in BAA-OCH3 and BAA-CH3. The asymmetric unit consists of two crystallographically independent molecules in BAA-OCH3. DFT computations show that the interaction energies between monomer and dimer are in the range of 0.5-3.8 kcal/mol with the B3LYP/6-31 + G*, B3LYP/6-31 ++G*, B3LYP/6-31 ++G**, and B3LYP/AUG-cc-pVDZ levels of theory. The presence of different hydrogen bond patterns is also governed by the substrate. For monomeric compounds studied herein, theoretical calculations lead to two low-energy conformers; trans (a) and cis (b). Former one is more stable than latter by about 4 kcal/mol. (C) 2016 Elsevier B.V. All rights reserved.

Kara, Hülya (Balikesir Author), Two "end-off" compartmental ligands, 2-formyl-4-chloro-6-N-ethylmorpholine-iminomethyl-phenol (HL1) and 2-formyl-4-methyl-6-N-ethylpyrrolidine-iminomethyl-phenol (HL2) have been designed and three complexes of Mn(II), one mono-, one di-and a polynuclear, namely Mn(L1)(SCN)(2)(H2O)] (1), [Mn-2(L1)-(OAc)(2)](BPh4)] (2), and [Mn-2(L-2)(OAc)(2)(dca)](n) (3) have been synthesized and structurally characterized. Variable temperature magnetic studies of 2 and 3 have been performed and data analyses reveal that Mn centers are antiferromagnetic coupled with J = -9.15 cm(-1) and J = -46.89, respectively. Catecholase activity of all the complexes has been investigated using 3,5-di-tert-butyl catechol (3,5-DTBC). All are highly active and the activity order on the basis of the k(cat) value is 2 > 1 > 3. In order to unveil whether the metal centered redox participation or the radical pathway is responsible for the catecholase-like activity of the complexes, detailed EPR and cyclic voltammetric (CV) studies have been performed. In addition to the six-line EPR spectrum characteristic to Mn(II), an additional peak at g similar to 2 is observed when the EPR study is done with the mixture of 3,5-DTBC and the catalyst, suggesting the formation of an organic radical, most likely ligand centered. The CV experiment with the mixture of 3,5-DTBC and the catalyst reveals ligand centered reduction rather than reduction of Mn(II) to Mn(I). It is thus inferred that complexes 1-3 show catecholase-like activity due to radical generation., Council of Scientific & Industrial Research (CSIR) - India - 01(2464)/11/EMR-II University Grants Commission, India - UGC/729/Jr Fellow(Sc)

Yahşi, Yasemin ( Balikesir Author ), The mu-oxo-bridged Fe(III) dimer complex [{Fe(4-MeOL1)}(2)(mu-O)]center dot HOCH3, (H-2-4-MeOL1 = N,N'-bis(4-methoxy- 2-hydroxybenzylidene)-2,2-dimethylpropane-1,3-diamine), 1 is synthesized and characterized by single crystal X-ray diffraction. Complex 1 contains a [{Fe(4-MeOL1)}(2)(mu-O)] dimeric unit with a methanol solvent molecule of crystallization. Each Fe(III) ion has a distorted square-pyramidal coordination geometry. In the basal plane, the Fe(III) atom is coordinated by two N and two O atoms of the Schiff base ligand. The apical position is occupied by a bridging O2- ion, linking another Fe(III) ion in the complex. There are intermolecular C-H. O and C-H....pi interactions among the dinuclear complexes.

Çoban, Mustafa Burak (Balikesir Author), A new coordination polymer, {[Ho(2-stp)(2)(H2O)(2)]center dot 2(4,4'-bipy)(1/2)center dot 5(H2O)}(n), 1, (2-stp = 2-sulfoterephthalate anion and 4,4'-bipy = 4,4'-bipyridine) has been synthesized by hydrothermal method and characterized by elemental analysis, IR, single-crystal X-ray diffraction. The Ho(III) atoms are bridged by two 2-stp ligands to form infinite chains which are associated through O-H center dot center dot center dot O interactions to build up 3D network and the free 4,4'-bipyridine molecules occupy the channel of the 3-D network. pi-pi stacking interactions exist between 4,4'-bipy and 2-stp ligands rings, with the centroid-to-centroid distance of 3.847 angstrom Additionally, solid state photoluminescence properties of 1 at room temperature have been investigated. Under the excitation of UV light, the compound 1 exhibited characteristic emissions of Ho(III) ion in the visible and the near-infrared (NIR) regions., Royal Society of London Dokuz Eylul University - 2010.KB.FEN.13

The synthesis, crystal structure and magnetic properties of [Mn(III)L(H2O)]2(H2O)(ClO4) (1)(L = N,N'-bis(rac-5-chlorosalicylidenato)-1,2-diaminopropane) are reported. Compound 1 consists of a structurally dinuclear system in which two Mn ions are bridged by the oxygen atoms of μ-phenoxo ligands. Low temperature magnetic susceptibility measurements show a ferromagnetic intra-dimer interaction with J = +1.75 cm−1, g = 2.01 and α = −0.32.

Yahşi, Yasemin (Balikesir Author), N,N'-bis(5-bromosalicylidene)propane-1,2-diamine-O,O',N,N')-manganese(III) chloride transition metal complex has been synthesized and characterized by elemental analysis and UV-vis spectroscopy. Its crystal structure has been determined using X-ray diffraction analysis. To provide an insight into the optical limiting (OL) behavior of the title compound, the third-order nonlinear optical (NLO) properties, one-photon absorption (OPA) and two-photon absorption (TPA) characterizations have been theoretically investigated by means of the time-dependent Hartree-Fock (TDHF), AM1 and configuration interaction (CI) methods, respectively. According to ab initio calculation results, the examined molecule exhibits second hyperpolarizabilities (gamma) with non-zero values at the positions of TPA peaks, implying microscopic third-order optical nonlinearity. The maximum OPA wavelengths recorded by linear optical experiment and quantum mechanical computations are estimated in the UV region to be shorter than 400 nm, showing good optical transparency to the visible light. The TPA cross-sections (delta(omega)) at lambda((2))(max) values indicate that the synthesized compound might possess OL phenomena, which are in accord with the experimental observations on the manganese complexes in the literature.

Kara, Hülya (Balikesir Author), A five-coordinate chloroiron(III) complex has been synthesized and characterized by X-ray diffraction analysis and UV-Vis spectroscopy. The maximum one-photon absorption ( OPA) wavelengths recorded by both linear optical measurements and quantum mechanical computations using the configuration interaction ( CI) method are estimated to be shorter than 400 nm in the UV region, showing good optical transparency to visible light. To investigate the microscopic third-order nonlinear optical ( NLO) behavior of the title compound, we have computed both dispersion-free ( static) and also frequency-dependent( dynamic) linear polarizabilities (alpha) and second hyperpolarizabilities (gamma) at lambda = 825 - 1125 nm and 1050 - 1600 nm wavelength areas using the time- dependent Hartree - Fock ( TDHF) method. The ab- initio calculation results with non- zero values on ( hyper) polarizabilities indicate that the synthesized molecule might possess microscopic third- order NLO phenomena.