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491.
Tushar S. Basu Baul Archana Mizar George Eng Michal Hol?apek Monique Biesemans Ray Butcher 《Journal of organometallic chemistry》2006,691(12):2605-2613
A series of cis-bis{5-[(E)-2-(aryl)-1-diazenyl]quinolinolato}dibenzyltin(IV) complexes have been synthesized by reacting sodium salts of 5-[(E)-2-(aryl)-1-diazenyl]quinolin-8-ol (LH) and dibenzyltin dichloride. These complexes have been characterized by 1H, 13C, 119Sn NMR, ESI-MS in solution and by IR and 119mSn Mössbauer, 117Sn CP-MAS NMR spectroscopy in solid state. In addition, the structures of three of the dibenzyltin(IV) complexes, viz., Bz2Sn(L2)2 (2), Bz2Sn(L3)2 (3), and Bz2Sn(L5)2 (5) (L = 5-[(E)-2-(aryl)-1-diazenyl]quinolin-8-ol: aryl = 4′-methylphenyl- (L2H), 4′-methoxylphenyl- (L3H) and 4′-bromophenyl- (L5H)) were determined by single-crystal X-ray diffraction. In general, the complexes were found to adopt a distorted cis-octahedral arrangement around the tin atom in both solution and solid state. 相似文献
492.
Brewer C Brewer G Butcher RJ Carpenter EE Cuenca L Noll BC Scheidt WR Viragh C Zavalij PY Zielaski D 《Dalton transactions (Cambridge, England : 2003)》2006,(8):1009-1019
The 1 : 3 Schiff base condensates of tris(2-aminoethyl)amine (tren) or tris(3-aminopropyl)amine (trpn) with 4-methyl-5-imidazolecarboxaldehyde, H3L1 and H3L2, respectively, were generated in situ and used to prepare complexes with manganese(II) and iron(III). The resultant complexes, [MnH3L1](ClO4)2, [MnH3L1](ClO4)2.EtOH.H2O, [MnH3L2](ClO4)2, [FeH3L1](ClO4)3.1.5(EtOH) and [FeHL1](I3) (0.525)(I)(0.475).2.625H2O, have been characterized by EA, IR, ES MS, variable temperature magnetic susceptibility, X-ray crystallography, and M?ssbauer spectroscopy for the iron complexes. The three manganese(II) complexes are high spin with [MnH3L2](ClO4)2 exhibiting coordination number seven while the others are six coordinate. [FeH3L1](ClO4)3.1.5(EtOH) has two iron sites, a seven coordinate and a pseudo seven coordinate site. The complex is high spin at room temperature but exhibits a magnetic moment that decreases with temperature corresponding to conversion of one of the sites to low spin. [FeHL1](I3) (0.525)(I)(0.475).2.625H2O is low spin even at room temperature. In the present complexes the apical nitrogen atom, N(ap), of the tripodal ligand is pyramidal and directed toward the metal atom. The data show that the M-N(ap) distance decreases as the oxidation state of the metal increases, as the number of bound imidazole protons on the ligand increases, and as the number of carbon atoms in the backbone of the ligand (tren vs. trpn) increases. In a limiting sense, short M-N(ap) distances result in high spin seven coordinate mono capped octahedral complexes and long M-N(ap) distances result in low spin six coordinate octahedral complexes. 相似文献
493.
Lin W Tryder N Su F Zercher CK Jasinski JP Butcher RJ 《The Journal of organic chemistry》2006,71(21):8140-8145
A zinc-mediated chain extension reaction is the key step in the preparation of gamma-keto amides derived from amino acids. The use of tandem reaction sequences, in which the intermediate zinc enolate is trapped with electrophilic reagents, results in the incorporation of alpha-substituents, which mimic the side chains found in natural amino acid systems. Use of the chiral amino acid L-proline as a stereo-directing element provides a diastereoselective route to various ketomethylene isosteres. 相似文献
494.
Ashok K.S. Chauhan Anamika Puspendra Singh Ray J. Butcher Andrew Duthie 《Journal of organometallic chemistry》2006,691(9):1954-1964
Monomeric tellurides 4-RC6H4(SB)Te [SB = 2-(4,4′-NO2C6H4CHNC6H3-Me); R = H, 1a; Me, 1b; OMe, 1c], which incidentally represent the first example of a telluride with 1,4-Te?N intramolecular interaction, have been prepared and characterized by solution and solid-state 125Te NMR, 13C NMR and X-ray crystallography. Interplay of weak C-H?O and C-H?π interactions in the crystal lattice of 1b and 1c are responsible for the formation of supramolecular motifs. These tellurides undergo expected oxidative addition reactions with halogens and interhalogens and also interact coordinatively with mercury(II) halides to give 1:2 complexes, HgX2[4-RC6H4(SB)Te]2 (X = Cl, R = H, 2a; Me, 2b; OMe, 2c and X = Br, R = H, 3a; Me, 3b; and OMe, 3c) with no sign of Te-C bond cleavage, as has been reported for some 1,5-Te?N(O) intramolecularly bonded tellurides. The complexes 2a and 3c are the first structurally characterized monomeric 1:2 adducts of mercury(II) halides with Te ligands. The 1,4-Te?N intramolecular interactions in the solid-state are retained in the complexes highlighting simultaneously the Lewis acid and base character of the Te(II) atom. Packing of molecules in the crystal lattice of 2a and 3c reveals that non-covalent C-H?Cl/Br interactions involving metal-bound halogen atoms possess significant directionality and in combination with coordinative covalent interactions may be of potential use in creating inorganic supramolecular synthons. 相似文献
495.
Ali Akbar Khandar Ray J. Butcher Marjan Abedi Seyed Abolfazl Hosseini-Yazdi Mehmet Akkurt M. Nawaz Tahir 《Polyhedron》2010
Utilizing a new 20-membered macrocyclic Schiff base ligand with two coordination sites formed from the [2+2] condensation of 1,3-diaminopropane and benzene-1,3-dicarboxaldehyde in the presence of CuX (X = Cl−, Br−, I−) salts, air-stable dicopper(I) complexes were synthesized in acetonitrile, intramolecularly linked via two halide groups, and characterized by different physico-chemical techniques. The single crystal X-ray diffraction technique indicates these complexes consist of two N2X2 donor sets that have distorted tetrahedral coordination environments around the copper(I) ions. In these halogen-bridged binuclear Cu2LX2 systems the Cu?Cu separation can be controlled, as this distance is reduced on increasing the halide size and hence the X?X repulsion, with the rigidity of the macrocycle playing a significant role. 相似文献
496.
Nand K. Singh Manoj K. Bharty Surendra K. Kushawaha Raymond J. Butcher 《Transition Metal Chemistry》2010,35(2):205-211
The products obtained by the reactions of Ni(OAc)2·4H2O with Hpot (Hpot = 5-phenyl-1,3,4-oxadiazole-2-thione) and [K(H2fchc)] (potassium N′-(furan-2-carbonyl) hydrazine carbodithioate), on treatment with excess of ethylenediamine (en), gave
mixed ligand complexes [Ni(pot)2(en)2] (1) and [Ni(fot)2(en)2] (2) (fot = 5-furan-(1,3,4)-oxadiazole-2-thione). These complexes have been characterized with the aid of elemental analyses,
IR, magnetic susceptibility and single crystal X-ray studies. In both complexes, the heterocyclic ligand coordinates through
oxadiazole nitrogen, and the ligand exists as the thione form. The complexes 1 and 2 have distorted octahedral geometries around the centrosymmetric Ni(II) center with trans oxadiazole ligands. Both complexes show extended hydrogen bonding to give a supramolecular framework. 相似文献
497.
498.
Marimuthu Sangavi Narayanasamy Kumaraguru Colin D. McMillen Ray J. Butcher 《Acta Crystallographica. Section C, Structural Chemistry》2023,79(10):435-442
Four salts, namely, 2,4,6-triaminopyrimidinium 6-chloronicotinate dihydrate, C4H8N5+·C6H3ClNO2−·2H2O, (I), 2,4,6-triaminopyrimidinediium pyridine-2,6-dicarboxylate dihydrate, C4H9N52+·C7H3NO42−·2H2O, (II), 2,4,6-triaminopyrimidinediium sulfate monohydrate, C4H9N52+·SO42−·H2O, (III), and 2,4,6-triaminopyrimidinium 3,5-dinitrobenzoate dihydrate, C4H8N5+·C7H3N2O6−·2H2O, (IV), were synthesized and characterized by X-ray diffraction techniques. Proton transfer from the corresponding acid to the pyrimidine base has occurred in all four crystal structures. Of the four salts, two [(I) and (IV)] exist as monoprotonated bases and two [(II) and (III)] exist as diprotonated bases. In all four crystal structures, the acid interacts with the pyrimidine base through N—H…O hydrogen bonds, generating an R22(8) ring motif. The sulfate group mimics the role of the carboxylate anions. The water molecules present in compounds (I)–(IV) form water-mediated large ring motifs. The formation of water-mediated interactions in these crystal structures can be used as a model in the study of the hydration of nucleobases. Water molecules play an important role in building supramolecular structures. In addition to these strong hydrogen-bonding interactions, some of the crystal structures are further enriched by aromatic π–π stacking interactions [(I) and (II)]. 相似文献