Yazar "Gumgum, Bahattin" seçeneğine göre listele

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    Aminophosphine-palladium(II) complexes: Synthsesis, structure and applications in Suzuki and Heck cross-coupling reactions
    (Elsevier Science Sa, 2011) Aydemir, Murat; Baysal, Akin; Sahin, Ertan; Gumgum, Bahattin; Ozkar, Saim
    Reaction of furfurylamine with 1 or 2 equivalents of PPh2Cl in the presence of Et3N, proceeds under anaerobic conditions in thf to give furfuryl-2-(N-diphenylphosphino)amine, Ph2PNHCH2-C4H3O, 1 and furfuryl-2-(N,N-bis(diphenylphosphino)amine), (Ph2P)(2)NCH2-C4H3O, 2, respectively. The reactions of 1 and 2 with MCl2(cod) (M = Pd, Pt; cod = 1,5-cyclooctadiene) or Pt(CH3)(2)(cod) yield complexes [M(Ph2PNHCH2-C4H3O)(2)Cl-2] (M= Pd 1a, Pt 1b), [Pt(Ph2PNHCH2-C4H3O)(2)(CH3)(2)] (1c), and [M((Ph2P)(2) NCH2-C4H3O)Cl-2] (M= Pd 2a, Pt 2b), [Pt((Ph2P)(2)NCH2-C4H3O)(CH3)(2)] (2c), respectively. All the compounds were isolated as analytically pure substances and characterized by NMR, IR spectroscopy and elemental analysis. Representative solid-state structures of 2a and 2b were also determined by X-ray single crystal diffraction technique. Furthermore, the palladium complexes 1a and 2a were tested and found to be highly active catalysts in the Suzuki coupling and Heck reaction affording biphenyls and trans-stilbenes, respectively. (C) 2011 Elsevier B.V. All rights reserved.
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    Comparison of microwave and conventional digestion of copper ores and determination of heavy metals by ICP-AES
    (Asian Journal Of Chemistry, 2006) Akba, Osman; Ozturk, Gulsen; Biricik, Nermin; Gumgum, Bahattin
    This paper summarizes the results obtained in applying conventional and microwave digestion techniques to Maden and Hazro copper materials for subsequent analysis by inductively coupled plasma (ICP-AES).
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    A modular design of ruthenium(II) catalysts with chiral C2-symmetric phosphinite ligands for effective asymmetric transfer hydrogenation of aromatic ketones
    (Pergamon-Elsevier Science Ltd, 2010) Aydemir, Murat; Meric, Nermin; Baysal, Akin; Gumgum, Bahattin; Togrul, Mahmut; Turgut, Yilmaz
    Hydrogen-transfer reduction processes are attracting increasing interest from synthetic chemists in view of their operational simplicity. The new chiral C-2-symmetric ligands N,N'-bis-[(1S)-1-sec-butyl-2-O-(diphenylphosphinite)ethyl]ethanediamide, 1 and N,N'-bis-[(1S)-1-phenyl-2-O-(diphenylphosphinite)ethyl]ethanediamide, 2 and the corresponding ruthenium complexes 3 and 4 have been prepared and their structures have been elucidated by a combination of multi-nuclear NMR spectroscopy, IR spectroscopy, and elemental analysis. H-1-P-31 NMR, DEPT, H-1-C-13 HETCOR, or H-1-H-1 COSY correlation experiments were used to confirm the spectral assignments. The catalytic activity of complexes 3 and 4 in transfer hydrogenation of acetophenone derivatives by iso-PrOH has also been studied. Under optimized conditions, these chiral ruthenium complexes serve as catalyst precursors for the asymmetric transfer hydrogenation of acetophenone derivatives in iso-PrOH and act as excellent catalysts, giving the corresponding chiral alcohols in 99% yield and up to 75% ee. This transfer hydrogenation is characterized by low reversibility under these conditions. (C) 2010 Elsevier Ltd. All rights reserved.
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    New active ruthenium(II) complexes based N3,N3?-bis(diphenylphosphino)-2,2?-bipyridine-3,3?-diamine and P,P?-diphenylphosphinous acid-P,P?-[2,2?-bipyridine]-3,3?-diyl ester ligands for transfer hydrogenation of aromatic ketones by propan-2-ol
    (Elsevier Science Sa, 2009) Aydemir, Murat; Baysal, Akin; Meric, Nermin; Gumgum, Bahattin
    The dimeric starting material [Ru(eta(6)-p-cymene)(mu-Cl)Cl](2) reacts with N3,N3'-bis(diphenylphosphino)-2,2'-bipyridine-3,3'-diamine, 1 and P,P'-diphenylphosphinous acid-P,P'-[2,2'-bipyridine]-3,3'-diyl ester, 2 ligands to afford bridged dinuclear complexes [C10H6N2{NHPPh2-Ru(eta(6)-p-cymene)Cl-2}(2)], 3 and [C10H6N2{OPPh2-Ru(eta(6)-p-cymene)Cl-22], 4 in quantitative yields. These bis(aminophosphine) and bis(phosphinite) based Ru(II) complexes serve as active catalyst precursors for the transfer hydrogenation of acetophenone derivatives in 2-propanol and especially 4 acts as a good catalyst, giving the corresponding alcohols in 99% yield in 20 min (TOF <= 280 h(-1)). (C) 2009 Elsevier B.V. All rights reserved.
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    Off-line determination of trace silver in water samples and standard reference materials by cloud point extraction-atomic absorption spectrometry
    (Estonian Acad Publishers, 2009) Kilinc, Ersin; Lepane, Viia; Viitak, Anu; Gumgum, Bahattin
    An off-line method for the determination of trace silver in water samples and certified reference materials by cloud point extraction (CPE) followed by flame atomic absorption spectrometry (FAAS) has been worked out. Preconcentration of CPE was based on complex formation of silver with dithizone in the presence of non-ionic micelles of octylphenoxy polyethoxy ethanol (Triton X-114) at pH 4.0. Optimization was performed on the variables influencing complexation and phase separation. The detection limit of silver in certified samples was 1.42 ng mL(-1), the quantification limit was 4.72 ng mL(-1), and precision expressed as relative standard deviation was 2.2% (n = 3, for silver concentration of 50 ng mL(-1)). The method was applied for the determination of trace silver in certified reference materials with satisfactory results.
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    Organometallic ruthenium, rhodium and iridium complexes containing a P-bound thiophene-2-(N-diphenylphosphino)methylamine ligand: Synthesis, molecular structure and catalytic activity
    (Elsevier Science Sa, 2011) Aydemir, Murat; Baysal, Akin; Meric, Nermin; Kayan, Cezmi; Gumgum, Bahattin; Ozkar, Saim; Sahin, Ertan
    Reaction of Ph2PNHCH2-C4H3S with [Ru(eta(6)-p-cymene)(mu-Cl)Cl](2), [Ru(eta(6)-benzene)(mu-Cl)Cl](2), [Rh(mu-Cl)(cod)](2) and [Ir(eta(5)-C5Me5)(mu-Cl)Cl](2) yields complexes [Ru(Ph2PNHCH2-C4H3S)(eta(6)-p-cymene)Cl-2], 1, [Ru(Ph2PNHCH2-C4H3S)(eta(6)-benzene)Cl-2], 2, [Rh(Ph2PNHCH2-C4H3S)(cod)Cl], 3 and [Ir(Ph2PNHCH2-C4H3S)(eta(5)-C5Me5)Cl-2], 4, respectively. All complexes were isolated from the reaction solution and fully characterized by analytical and spectroscopic methods. The structure of [Ru(Ph2PNHCH2-C4H3S)(eta(6)-benzene)Cl-2], 2 was also determined by single crystal X-ray diffraction. 1-4 are suitable precursors forming highly active catalyst in the transfer hydrogenation of a variety of simple ketones. Notably, the catalysts obtained by using the ruthenium complexes [Ru(Ph2PNHCH2-C4H3S)(eta(6)-p-cymene)Cl-2], 1 and [Ru(Ph2PNHCH2-C4H3S)(eta(6)-benzene)Cl-2], 2 are much more active in the transfer hydrogenation converting the carbonyls to the corresponding alcohols in 98-99% yields (TOF <= 200 h(-1)) in comparison to analogous rhodium and iridium complexes. (C) 2011 Elsevier B.V. All rights reserved.
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    Spectroscopic and Thermogravimetric Investigation of Cd(II) Dinonyldithiophosphate: Removal of Cadmium from Aqueous Solutions
    (Hindawi Ltd, 2015) Biricik, Nermin; Gumgum, Hadice Budak; Gumgum, Bahattin
    Dinonyldithiophosphoric acid (HDDTP) was synthesised from the reaction of phosphorus pentasulphide and nonyl alcohol. Dinonyldithiophosphate complex of cadmium [Cd(DDTP)(2)] was prepared by mixing solutions of Cd(II) with HDDTP in ethanol at room temperature. The acid and its complex were characterised by elemental analysis and spectroscopy. The thermal behaviour of Cd(DNDTP)(2) was investigated by thermogravimetric analysis. Removal of Cd(II) from aqueous media by HDDTP solution was also studied. The optimum conditions for removal of Cd(II) were investigated for effects of solvent, pH, contact time, concentration, and inorganic anions. Cd(II) was quantitatively removed from aqueous solutions at the pH range of 0.5 < pH < 6, under the conditions that the stoichiometric ratio of HDDTP/Cd(II) = 2/1. It can be stated that contact of the Cd(II) with HDDTP was sufficient for quantitative removing of cadmium from acidic aqueous solutions.
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    Synthesis and characterization of ether-derivatized aminophosphines and their application in C-C coupling reactions
    (Elsevier Science Sa, 2010) Biricik, Nermin; Kayan, Cezmi; Gumgum, Bahattin; Fei, Zhaofu; Scopelliti, Rosario; Dyson, Paul J.; Gurbuz, Nevin
    Four new bis(phosphino) amine ligands (Ph2P)(2)N-C6H3-R, where R = 3,5-OMe (1), 2,5-OMe (2), 2,4-OMe (3) or 3,4-OMe (4), were prepared via aminolysis of the corresponding dimethoxyanilines with 2 equiv. of diphenylphosphine chloride in the presence of triethyl amine. Oxidation of these ligands with aqueous H2O2, elemental S-8 or Se powder afforded the corresponding chalcogen oxides 1a-4a, sulfides 1b-4b and selenides 1c-4c in good yields. Reaction of 1-4 with [MCl2(cod)] (M = Pt, Pd; cod = cycloocta-1,5-diene) in equimolar ratios afforded cis-[MCl2{(Ph2P)(2)N-C6H3-R}] (M = Pt; R = 3,5-OMe 1d, R = 2,5-OMe 2d, R = 2,4-OMe 3d, and R = 3,4-OMe 4d. M = Pd; R = 3,5-OMe 1e, R = 2,5-OMe 2e, R = 2,4-OMe 3e, and R = 3,4-OMe 4e). Similarly, reaction of [Cu(CH3CN)(4)]PF6 with the 1-4 in 1:2 ratio gave [Cu{(Ph2P)(2)N-C6H3-R}(2)]PF6 (R = 3,5-OMe 1f, 2,5-OMe 2f, 2,4-OMe 3f and 3,4-OMe 4f). All new compounds were fully characterized by spectroscopy and elemental analysis and the molecular structures of seven representative compounds were determined by single-crystal X-ray crystallography. In addition, the palladium complexes were investigated as pre-catalysts in C-C coupling reactions. (C) 2009 Elsevier B.V. All rights reserved.
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    Synthesis and characterization of new bis(diphenylphosphino)aniline ligands and their complexes: X-ray crystal structure of palladium(II) and platinum(II) complexes, and application of palladium(II) complexes as pre-catalysts in Heck and Suzuki cross-coupling reactions
    (Pergamon-Elsevier Science Ltd, 2009) Aydemir, Murat; Durap, Feyyaz; Baysal, Akin; Akba, Osman; Gumgum, Bahattin; Ozkar, Saim; Yildirim, Leyla Tatar
    Two new bis(diphenylphosphino)isopropylphenylamines, (PPh2)(2)N-C6H4-CH(CH3)(2), having the isopropyl substituent at the carbon atom 2 (1) or 4 (2), were prepared by the aminolysis of chlorodiphenylphosphine with isopropyl substituted aniline at the ortho- or para-position, respectively, under anaerobic conditions. Oxidation of 1 and 2 with either aqueous hydrogen peroxide, elemental sulfur or grey selenium in thf gave the corresponding oxides, sulfides and selenides (Ph2P=E)(2)N-C6H4-CH(CH3)(2), where E = O, S or Se, respectively. The palladium and platinum complexes [M{(Ph2P)(2)N-C6H4-CH(CH3)(2))Cl-2] (M = Pd, Pt) and the copper complex [Cu((Ph2P)(2)N-C6H4-CH(CH3)(2))(2)]PF6 were isolated from the reaction of the bis(phosphino)anilines with MCl2(cod) or [Cu(CH3CN)(4)]PF6, respectively. The new compounds were characterized by NMR, IR spectroscopy and elemental analysis. Furthermore, the solid-state structures of two representative complexes were determined using single crystal X-ray diffraction analysis. The compounds of palladium (1d) and platinum (1e), both mononuclear complexes, crystallize in the monoclinic P2(1)/c space group. In both compounds the metal ion has a distorted square-planar coordination geometry. The structural properties of complexes Id and le in the solid state are very similar. The palladium complexes were also tested for their catalytic activities in C-C coupling reactions. (C) 2009 Elsevier Ltd. All rights reserved.
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    Synthesis and characterization of polyoxometallate compounds of amine and phosphine with molybdovanadophosphoric acid in Keggin type
    (Asian Journal Of Chemistry, 2006) Gumgum, Bahattin; Akba, Osman; Baysal, Akin; Hamamci, Candan
    Four novel compounds were synthesized by the reaction of tertiary amines (triphenyl amine, triethyl amine, tributyl amine) and triphenyl phosphine with freshly prepared molybdovanadophosphoric acid (H4PMO11VO40 center dot 32H(2)O). The products were characterized by elemental analysis, spectroscopic techniques (UV, IR, ICP-AES) and thermal analysis (TG/DTA). The experimental data indicated that the synthesized compounds retain the Keggin structure.
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    Synthesis and characterization of tris{2-(N,N-bis(diphenylphosphino) aminoethyl} amine derivatives: Application of a palladium(II) complex as a pre-catalyst in the Heck and Suzuki cross-coupling reactions
    (Elsevier Science Sa, 2008) Aydemir, Murat; Baysal, Akin; Gumgum, Bahattin
    The polydendate bis(phosphino) amine, tris{2-(N,N-bis(diphenylphosphino) aminoethyl} amine 1 has been prepared in a single step from the reaction of tris( 2- aminoethyl) amine with six equivalents of PPh2Cl in the presence of NEt3 in THF. Oxidation of 1 with aqueous H2O2, elemental sulfur or grey selenium gave the corresponding oxide, sulfide or selenide derivatives. [{(P(E)Ph-2)(2)NCH2CH2}(3)N] (E: 2a O, 2b S, 2c Se), respectively. Reactionof [{(PPh2)(2)NCH2CH2}(3)N] with 3 equiv. of PdCl2(cod) or PtCl2(cod) gave the corresponding chelate complexes, [Pd(3)Cl(6)1] or [Pt(3)Cl(6)1]. The new compounds were fully characterized by NMR, IR spectroscopy and elemental analysis. The catalytic activity of the Pd(II) complex was tested in the Suzuki coupling and Heck reactions. The Pd(II) complex catalyzed the Suzuki coupling and Heck reaction affording biphenyls and stilbenes, respectively, in high yields. (c) 2008 Elsevier B.V. All rights reserved.
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    Synthesis and reactivity of N,N-bis(diphenylphosphino)dimethylaniline compounds
    (Springer, 2007) Biricik, Nermin; Durap, Feyyaz; Gumgum, Bahattin; Fei, Zhaofu; Scopelliti, Rosario
    New chalcogenides and complexes of N,N-bis(diphenylphosphino)dimethylanilines were prepared by the reaction of N,N-bis(diphenylphosphino)dimethylaniline ligands with aqueous H2O2, elemental S and Se and transition metal complexes based on Cu, Pd and Pt. All the new compounds have been characterised by spectroscopy and the molecular structures of the three complexes of N,N-bis(diphenylphosphino)dimethylanilines have been determined by X-ray crystallography.
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    Synthesis of new thiol-derivatized aminophosphines and their catalytic activities in C-C coupling reactions
    (Tubitak Scientific & Technological Research Council Turkey, 2015) Biricik, Nermin; Meric, Nermin; Kayan, Cezmi; Ozgen, Zeynep; Azizoglu, Sevil Seker; Gumgum, Bahattin
    A series of new aminophosphines [Ph2PHN-C6H4-R, where R = o-SH (4a), m-SH (4b) or p-SH (4c)] were readily synthesized from cheap starting materials by the phosphorylation reaction of o, m, and p-aminothiophenols with Ph2PCl in the presence of triethyl amine. The new compounds were characterized by NMR and IR spectroscopy and microanalysis. In addition, aminophosphine ligands palladium systems were investigated as precatalysts in C-C coupling reactions. Compounds 4b and 4c were proved to be excellent catalysts for Suzuki and Heck cross-coupling reactions.
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    Synthesis, Characterization and Molecular Structure of a Novel Schiff Base, N3,N3?-di-2-hydroxybenzylidene-[2,2?]bipyridinyl-3,3?-diamine
    (Int Union Crystallography, 2007) Baysal, Akin; Buldag, Aysegul; Gumgum, Bahattin; Ozkar, Saim; Yildirim, Leyla Tatar
    [Abstract Not Available]
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    Synthesis, spectral characterization and electrochemical properties of new vic-dioxime complexes bearing carboxylate
    (Springer, 2006) Kilic, Ahmet; Tas, Esref; Gumgum, Bahattin; Yilmaz, Ismail
    Three new vic-dioxime ligands, [N-(ethyl-4-amino-1-piperidine carboxylate)-phenylglyoxime ((LH2)-H-1), N-(ethyl-4-amino-1-piperidine carboxylate)-glyoxime (L(2)pH(2)), and N,N'-bis(ethyl-4-amino-1-piperidine carboxylate)-glyoxime ((LH2)-H-3)], and their Co(II) with Cu(II) metal complexes, were synthesized for the first time. Mononuclear complexes of these ligands with a 1:2 metal-ligand ratio were prepared with Co(II) and Cu(II) salts. The BF2+-capped Co(II) and mononuclear complexes of the vic-dioxime were prepared for [Co(L-1 center dot BF2)(2)] and [Co(L-2 center dot BF2)(2)]. The ligands act in a polydentate fashion bonding through nitrogen atoms in the presence of a base, as do most vic-dioximes. The cobalt(II) and copper(II) complexes are non-electrolytes as shown by their molar conductivities (Lambda(M)) in DMF. The structures of the ligands and complexes were determined by elemental analyses, FT-i.r., u.v.-vis., H-1- and C-13-n.m.r. spectra, magnetic susceptibility measurements, and molar conductivity. The comparative electrochemical studies show that the stabilities of the reduced or oxidized species and the electrode potentials of the complexes are affected by the substituents attached on the oxime moieties of the complexes.
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    The synthesis, spectroscopic and voltametric studies of new metal complexes containing three different vic-dioximes
    (Taylor & Francis Ltd, 2007) Kilic, Ahmet; Tas, Esref; Gumgum, Bahattin; Yilmaz, Ismail
    The synthesis, spectroscopic, and redox properties of some metal complexes with three novel vic-dioxime ligands, N-(1-(2-aminoethyl) piperazine)-phenylglyoxime (L1H2), N-(1-(2-aminoethyl) piperazine)-glyoxime (L2H2), and N, N'-bis(1-(2-aminoethyl) piperazine)-glyoxime (L3H2)], prepared from different glyoxime and 1-(2-aminoethyl) piperazine are reported. The structure of these vic-dioximes have been determined as the anti-form according to H-1 NMR, C-13 NMR, and FT-IR data. The metal to ligand ratios of Co(II), Ni(II), and Cu(II) complexes were found to be 1:2. The Cu(II) complexes of these ligands are proposed to be square planar and Ni(II) complexes of these ligands are proposed to be square planar or octahedral, while the Co(II) complexes are proposed to be octahedral with water molecules as axial ligands. Ni(II), Co(II), and Cu(II) metal complexes are non-electrolytes as shown by their molar conductivities (Lambda(M)) in DMF (dimethyl formamide) at 10(-3) M. The structure of ligands and their complexes is proposed from elemental analysis, FT-IR, UV-VIS, H-1 NMR, C-13 NMR, magnetic susceptibility measurements, and molar conductivity measurements. The cyclic voltammetric measurements of the mononuclear complexes provide an understanding of the electrochemical behaviour of the reduced or oxidized species in DMSO solution.