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Öğe Antimicrobial activity of carbene complexes of rhodium(I) and ruthenium(II)(Ecv-Editio Cantor Verlag Medizin Naturwissenschaften, 1996) Cetinkaya, B; Cetinkaya, E; Kucukbay, H; Durmaz, RTwenty-four carbene-rhodium(I), carbene-ruthenium(II) complexes and related compounds were evaluated for their in vitro antimicrobial activity against the Cram-positive bacteria Enterococcus faecalis (ATCC 29212) and Staphylococcus aureus (ATCC 29213) and Gram-negative bacteria Escherichia coli (ATCC 25922), Pseudmonas aeruginosa (ATCC 27853).Öğe cis-1,1'-Dimethyl-3,3'-diphenyl-2,2'-biimidazolidinylidene(Munksgaard Int Publ Ltd, 1997) Ulku, D; Tahir, MN; Cetinkaya, B; Ozdemir, IThe structure of the air-sensitive title compound consists of C20H24N4 molecules connected through a hydrogen bond. Neither the molecule as a whole nor the individual five-membered rings have a planar geometry. The dihedral angle between the best planes of the two phenyl rings is 50.87 (14)degrees. Weak intermolecular hydrogen bonding is observed between a C atom and an imidazolidine N atom.Öğe Crystal structure of [RuCl2[N-(2,4,6-trimethyl-benzyl)N-(n-butyl)]-imidazolidin-2-ylidene] and [RuCl2[N-(2,4,6-trimethyl-benzyl)-N-(2-methoxyethyl)]imidazolidin-2-ylidene](Springer/Plenum Publishers, 2005) Arslan, H; VanDerveer, D; Ozdemir, I; Cetinkaya, B; Demir, STwo imidazolidin ruthenium complexes, [RuCl2[N-(2,4,6-trimethyl-benzyl)-N-(n-butyl)]imidazolidin-2-ylidene], 1, and [RuCl2[N-(2,4,6-trimethyl-benzyl)-N-(2-methoxyethyl)]imidazolidin-2-ylidene], 2, have been synthesised and their crystal structures have been determined from single crystal X-ray diffraction data. Compound I is monoclinic, of space group C2/c with a = 18.466(4) angstrom, b = 14.816(3) angstrom, c = 15.413(3) angstrom, beta = 118.067(2)degrees, and V = 3720.9(12) angstrom(3) with Z = 8 for d(calc) = 1.536 g/cm(3). Compound 2 is monoclinic, of space group P2(1)/c with a = 8.1800(5) angstrom, b = 14.344(8) angstrom, c = 14.809(9), beta = 91.604(10)degrees, and V = 1736.7(18) angstrom(3) with Z = 4 for d(calc) = 1.653 g/cm(3). In each complex the ligand functions as an arene and carbene, occupying four coordination sites. The two chlorines in each compound complete a distorted octahedron.Öğe Crystal structure of dichlorido(N-(biphenyl-2-ylmethyl)-N-(2-ethoxy-ethyl)]-imidazolidin-2-ylidene(?6-hexamethylbenzene)ruthenium, Ru(C12H18)(C20H24N2O)Cl2(R Oldenbourg Verlag, 2004) Arslan, H; Vanderveer, D; Özdemir, I; Cetinkaya, B; Yasar, SC32H42Cl2N2ORu, monoclinic, P12(1)/cl (no. 14), a = 12.930(4) Angstrom, b = 18.094(6) Angstrom, c = 13.655(4) Angstrom, beta = 114.00(2)degrees, V = 2918.4 Angstrom(3), Z = 4, R-gt(F) = 0.046, wR(ref)(F-2) = 0.133, T = 193 K.Öğe Crystal structure of dichloro-N-(3,4,5-trimethoxy-benzyl)-N-(n-butyl)]imidazolidin-2-ylideneruthenium(II), RuCl2(C17H26N2O3)(R Oldenbourg Verlag, 2004) Arslan, H; Vanderveer, D; Özdemir, I; Cetinkaya, B; Demir, SC17H26Cl2N2O3Ru, monoclinic, P12(1)/nl (no. 14), a = 10.180(1) A, b = 11.985(1) A, c = 16.017(2) A, beta = 106.419(2)degrees, V = 1874.5 A(3), Z = 4, R-gt(F) = 0.037, wR(ref)(F-2) = 0.109, T = 193 K.Öğe New (carbene)ruthenium-arene complexes: Preparation and uses in catalytic synthesis of furans(Amer Chemical Soc, 1996) Kucukbay, H; Cetinkaya, B; Guesmi, S; Dixneuf, PHA variety of neutral ruthenium-carbene complexes RuCl2(carbene)(arene) 1 (carbene=C(NR)C6H4(NR), R=Me (a), Et (b); arene=p-Me-C6H4-Pr-i (1), C(6)H(3)Me(3) (2), C(6)Me(6) (3)) have been prepared by reaction of [RuCl2(arene)](2) precursors with the enetetraamines (RN)C6H4(RN)C=C(NR)C6H4(NR) I (R=Me) and II (R=Et). Ru=C(NCH(2)Ph)CH2CH2(NCH(2)Ph)Cl-2(p-cymene) (4) was prepared similarly, whereas the reaction of [RuCl2-(cycloocta-1,5-diene)](n) with I led to the formation of the 16-electron neutral complex RuCl2[=C(NMe)C6H4(NMe)](3) (6). One of them (3a) was transformed into the dihydride derivative RuH2(C(NMe)C(6)H(4)NMe)(C(6)Me(6)) (5). The cyclic voltammograms of derivatives 1-3 show that they are oxidized in the range E(1/2)=1.03-1.31 V vs SCE and are more electrophilic than the isoelectronic RuCl2(PR(3))(arene) complexes. Derivatives 1a, 3a, and 3b act as efficient catalyst precursors for the electrophilic activation of the C=C bond of (Z)-3-methylpent-2-en-4-yn-1-ol to afford 2,3-dimethylfuran in good yield via intramolecular cyclization.Öğe Reactions of electron-rich olefins with proton-active compounds(Marcel Dekker Inc, 1997) Kucukbay, H; Cetinkaya, E; Cetinkaya, B; Lappert, MFFrom the reaction of electron-rich olefins, bis(1,3-dimethylbenzimidazolidine-2-ylidene), I, or bis(3-methylbenzothiazolidine-2-ylidene), LI with proton active compounds, such as dimethyl phosphite, diethyl phosphite, acetonitrile and benzaldehyde were obtained 2-substituted benzimidazole or benzothiazole derivatives. The compounds synthesized were identified by H-1, C-13, P-31-NMR, mass, FT-LR spectroscopic techniques and micro analysis.Öğe Ruthenium-carbene catalysts for the synthesis of 2,3-dimethylfuran(Elsevier Science Bv, 1997) Cetinkaya, B; Ozdemir, I; Bruneau, C; Dixneuf, PHA variety of neutral arene-ruthenium-carbenes of type (arene)RuCl2(=C(NR)CH(2)CH(2)NR) have been used for the catalytic transformation of (Z)-3-methylpent-2-en-4-yn-l-ol into 2,3-dimethylfuran. The catalytic reaction takes place at 80 degrees C with mononuclear complexes III-V to afford the furan in similar to 90% yield. The binuclear catalysts VIa and VIIa having a linked bis-carbene bridge operate at room temperature to initiate an exothermic reaction offering 90-97% of furan.Öğe Synthesis and antimicrobial activity of electron rich olefin derived cyclic ureas(Ecv-Editio Cantor Verlag Medizin Naturwissenschaften, 1996) Cetinkaya, B; Cetinkaya, E; Kucukbay, H; Durmaz, RSeventeen cyclic ureas containing imidazolidine and benzimidazoline nuclei were synthesised by the reaction of electron-rich olefins with appropriate group 16 elements (O, S, Se, Te). The compounds synthesised were identified by H-1, C-13-NMR, FT-IR and mass spectroscopic techniques and micro analysis. All compounds studied in this work were screened for their in vitro antimicrobial activity against standard strains: Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (ATCC 29213), Escherichia coli (ATCC) 25922) and Pseudomonas aeruginosa (ATCC 27853). Eight of the compounds were found effective to inhibit the growth of Gram-positive bacteria (Enterococcus Faecalis and Staphylococcus aureus) at MIC values between 25-400 mu g/ml. None of the compounds exhibit antimicrobial activity against gram-negative bacteria (Escherichia coli; and Pseudmonas aeruginosa) at the concentrations studied (6.25-800 mu g/ml).Öğe Synthesis and catalytic properties of arene complexes of ruthenium(II) prepared from Si, Zr, Ti and Al alkoxides by the sol-gel process(Royal Soc Chemistry, 1998) Cetinkaya, B; Seckin, T; Ozdemir, I; Alici, BMethods of synthesizing materials for catalysis were developed by synthesizing eta-arene complexes of ruthenium(II) coordinated to vinylpyridine that was followed by sol-gel polymerization with 3-methacryloxypropyltriethoxysilane. To enforce sufficient catalytic properties, a series of hybrid materials from Si, Zr, Ti and Al alkoxides were prepared by co-condensation. The hydrolysis and polycondensation of materials were performed at different experimental conditions. The monomeric compounds were identified and catalytic activities were tested for cyclization of (Z)-3-methylpent-2-en-4-yn-1-ol to 2,3-dimethylfuran.Öğe Synthesis and catalytic properties of N-functionalized carbene complexes of rhodium(I) and ruthenium(II)(Elsevier Science Sa, 1997) Cetinkaya, B; Ozdemir, I; Dixneuf, PHImidazolidin-2-ylidene derivatives of rhodium(I) and ruthenium(II), having 2-methoxyethyl substituent on the N-atom, [Rh(L)Cl(PPh3)(2)], [Rh(L)Cl(COD)] or [Ru(L)Cl-2(arene)] (L-1 = CN(Me)CH2CH2NCH2CH2OMe and L-2 = CN(CH2CH2OMe)CH2CH2NCH2CH2OMe) have been prepared by treatment of [RhCl(PPh3)(3)], [RhCl(COD)](2) or [RuCl2(arene)](2) with the N-functionalized electron-rich olefins L-1 = L-1 or L-2 = L-2. All of the new carbene rhodium(I) or ruthenium(II) complexes have proved to be effective catalysts for the cyclopropanation reactions of diazoalkane derivatives with styrene and the rhodium(I) precursors lead to the highest catalytic activity.Öğe A synthesis and properties of 1-substituted 1,4,5,6-tetrahydropyrimidines(Pergamon-Elsevier Science Ltd, 1997) Alici, B; Cetinkaya, E; Cetinkaya, BThe condensation of 1-substituted 1,3-diaminopropane with N,N-dimethylformamide dimethylacetal gives 1-alkyl- or aryl-1,4,5,6-tetrahydropyrimidines (2) and (3). Alkylation of the tetrahydropyrimidine derivatives with alkyl halides produces the 1,3-dialkyltetrahydropyrimidinium salts (4 and 5). The attempted dehydrogenation of 2 with sulfur leads to insertion of sulfur on the molecule.Öğe Synthesis of a water-soluble carbene complex and its use as catalyst for the synthesis of 2,3-dimethylfuran(Elsevier Science Sa, 2001) Özdemir, I; Yigit, B; Cetinkaya, B; Ülkü, D; Tahir, MN; Arici, C1,1,3,3'-Tetrakis(p-dimethylaminobenzyl)-2,2'-biimidazolidinylidene, L-2(R) (R = CH2C6H4NMe2-p) which contains four peripheral NMe2 substituents, was obtained from 4-dimethylaminobenzaldehyde by a three-step reaction sequence, and was used for the preparation of imidazolidin-2-ylidene Ru(II) and Rh(I) complexes 1 and 2. Etherial HCl readily protonates the NMe2 functionality on the carbene ligand of 1 to give the corresponding salt, 1'; whereas the reaction of 2 with HCl gave a hygroscopic and ill-defined rhodium species. In aqueous solution the salt 1' is an efficient and active catalyst for intramolecular cyclisation of (Z)-3-methylpent-2-en-4-yn-1-ol into 2,3-dimethylfuran. The catalyst 1' could be recovered by simple phase separation and the catalytic reaction was maintained for five different runs. All of the new compounds were characterised by elemental analyses, IR and NMR spectroscopy and the molecular structure of I was determined by X-ray crystallography. (C) 2001 Elsevier Science B.V. All rights reserved.Öğe Synthesis of cis- and trans-dichloro(dimethylphenylphosphine) x-(1-methyl-1,4,5,6-tetrahydropyrimidine)platinum(II) and their spectral and structural characterization(Elsevier Science Sa, 1998) Cetinkaya, B; Ozdemir, I; Tahir, MN; Ulku, DInteraction of [{Pt(mu-Cl)Cl(PMe2Ph)}(2)] with 1-methyl-1,4,5,6-tetrahydropyrimidine, L (R = Me), in boiling toluene produced a mixture of cis- and trans- isomers of [PtCl2(PMe2Ph){N = CH(Me)CH2CH2CH2}] trans-complex 2 isomerizes to give thermody-namically more stable corresponding cis-complex 1 in boiling ethanol. Spectroscopic and X-ray diffraction data permit generalizations about cis- and trans- isomeric pairs to be made. In addition, the trans influence of the ligand L is reliably assessed. (C) 1998 Elsevier Science S.A. All rights reserved.Öğe Synthesis of tetraaminoalkenes containing the reduced pyrimidine skeleton and the x-ray molecular structure of 1,1'-ethylene-3,3'-dibenzylbi(hexahydropyrimidin-2-ylidene)(Royal Soc Chemistry, 1996) Alici, B; Cetinkaya, E; Cetinkaya, B; Ulku, D; Tahir, MNDeprotonation of a 1,1'-bridged bis(1,3-diaikyl-1,4,5,6-tetrahydropyrimidinium) diiodide with NaH gives in high yield a tetraaminoalkene 4, whereas the corresponding non-bridged tetrahydropyrimidinium iodide reacts with NaH only in the presence of KOBu; the title bridged tetraaminoalkene 4f was structurally characterized by single-crystal X-ray diffraction.Öğe Unusual products in the reactions of hexachlorocyclotriphosphazatriene with sodium aryloxides(Wiley, 1996) Kilic, A; Begec, S; Cetinkaya, B; Hokelek, T; Kilic, Z; Gunduz, N; Yildiz, MReactions of hexachlorocyclotriphosphazatriene, N3P3Cl6 1, with sodium aryloxides have been studied. Compound 1 was found to react by the nucleophilic substitution path way to yield monocyclophosphazenes [N3P3Cl5(OC(6)H(2)Bu(3)(t)-2, 4, 6) 5 and N3P3Cl4(OC(6)H(2)Me-4-Bu(2)(t)-2, 6)(2) 6] and bi(cyclophosphazenes) ([Cl5N3P3-P3N3Cl4(OC(6)H(3)Bu(2)(t)-2, 6)] 7 and [N3P3(OC(6)H(3)Bu(2)(t)-2, 6)(5)](2) 8]. The unusual bi(cyclophosphazenes) 7 and 8 are the first examples of two cyclotriphosphazene rings linked by a P-P bond [2.193 (2) Angstrom], which have been obtained by reacting 1 with ArONa. The structures of compounds 5-8 ave ascertained by elemental analyses, H-1-, P-31-C-13-NMR, IR, and MS spectra. The molecular structure of monocyclic-phosphazene 5 was determined by X-ray diffraction techniques for further structural assignment. It crystallizes in the monoclinic space group P2(1)/m with a = 6.144(2), b = 17.079(9), c = 13.181(9) Angstrom, beta = 92.79(7), and Z = 2, R = 0.074. Compound 5 is on a crystallographic mirror plane, and there is only a half molecule in the asymmetric unit. (C) 1996 John Wiley & Sons, Inc.
