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111.
Complex formation equilibria involving [Pd(bpy)(H2O)2]2+ (bpy = 2,2-bipyridine) and the cyclobutanedicarboxylate ligand (cbdca), ethylenediamine and DNA have been investigated. Mixed ligand complexes of [Pd(bpy)(cbdca)] with inosine, inosine-5-monophosphate (5-IMP), uracil, uridine and adenine have been studied. The results show ring opening of the cbdca and monodentate chelation of the DNA components. Stoichiometries and stability constants for the complexes were determined at 25 °C and at constant 0.1 M ionic strength (adjusted using NaNO3). The coordination sites were found to be pH-dependent. The [Pd(bpy)Cl2], [Pd(bpy)(cbdca)] and [Pd(bpy)(inosine)](NO3) complexes were isolated. 相似文献
112.
Detlef Gabel Claudia Bauer Mohamed E. El-Zaria Afaf R. Genady Udo Drfler 《Journal of organometallic chemistry》2003,680(1-2):23-26
The preparation and properties of the R1R2NH---B8H11NHR cluster are described. The cluster is stable to aqueous solutions and can be made water-soluble by the introduction of a few hydrophilic groups. This makes the cluster a good candidate as the boron moiety in compounds for boron neutron capture therapy. The chemistry of the cluster preparation, the stability of the cluster, and conditions for reactions of the organic moieties are reviewed. Pyridine derivatives of the cluster show electronic interaction between the cluster and the pyridine. 相似文献
113.
Christelle Titier Jean-Pierre Pascault Mohamed Taha Boris Rozenberg 《Journal of polymer science. Part A, Polymer chemistry》1995,33(1):175-184
Epoxy-amine methacrylated prepolymers are prepared in a 1-step synthesis by the reaction of Bisphenol A diglycidyl ether, glycidyl methacrylate, and different diamines. The adaptation of these reactions to production processes with a reduced reaction time requires a kinetic control and the use of efficient catalysts. The comparative kinetic treatment of the epoxy-amine reaction in the frame of Horie's and Rozenberg's kinetic schemes have been made. Cases where an efficient acid catalyst is used are also examined. Structural studies of these reactions established the occurrence of a Michael amine/double bond addition, when some amines are used. © 1995 John Wiley & Sons, Inc. 相似文献
114.
Ahmad M. Farag Abdelgawad A. Fahmi Abdou O. Abdelhamid Ahmad S. Shawali Mohamed S. Algharib 《Journal of heterocyclic chemistry》1987,24(5):1341-1344
The reaction of diazotized 3-phenyl-5-aminopyrazole with phenacyl thiocyanate 1a and phenacyl selenocyanate 1b afforded directly 2-imino-3-(3-phenyl-5-pyrazolyl)-5-benzoyl-2,3-dihydro-1,3,4-thiadiazole monohydrate 9a and 2-imino-3-(3-phenyl-5-pyrazolyl)-5-benzoyl-2,3-dihydro-1,3,4-selenadiazole monohydrate 9b , respectively. The products 9a and 9b were also obtained from the reaction of C-benzoyl-N-(3-phenyl-5-pyrazolyl)formohydrazidoyl bromide 10 with potassium thiocyanate and potassium selenocyanate, respectively. Acetylation, benzoylation, and nitrosation of 9 afforded the corresponding diacetyl, dibenzoyl, and nitroso derivatives 11-13 , respectively. Cyclization of C-benzoyl-N-(3-phenyl-5-pyrazolyl)-nitrilimine 6 was shown to give the pyrazolo [5,1-d]triazole 8 and not the pyrazolo[5,1-c]-as-triazine derivative 7 , as previously reported. 相似文献
115.
A mixed ligand 12 complex of copper(II) azide with 3,5-lutidine, namely di-(1,1)-azido-di(0,0)-nitrato)tetrakis(3,5-lutidine)dicopper(II) has been prepared and characterized by X-ray crystallographic and spectroscopic methods. The dimeric molecule, which possesses a crystallographic inversion center, contains two(1,1) bridging azido ligands. Each copper(II) atom in the cyclic Cu2N2 unit is further coordinated by two oxygen atoms from two(0,0-nitrato) bridges at Cu-O distances of 2.465(3) and 2.568(3) Å and two nitrogen atoms from the lutidine molecules [Cu-N=2.003(3) and 2.012(3) Å] to give a distorted tetragonal bipyramid. Both azido ligands are linear [N-N-N angle=179.0(4) and asymmetric N-N=1.207(4) and N-N=1.135(5) Å]. The azido bridges produce a rather short Cu Cu distance of 3.013(2) Å. Infrared and electronic data are presented and discussed. 相似文献
116.
Mohamed M. Shoukry Kamal Aziz Eman M. Shoukry Samia Hamdallah 《Transition Metal Chemistry》1989,14(2):115-118
Summary The formation constants of 1-phenyl-3-thiazole-2-ylthiourea complexes with some bivalent metal ions (CuII, NiII, ZnII and MnII) have been determined in 75% EtOH–H2O. Complexes of CuII, NiII, ZnII, HgII and PdII have been isolated and characterized by conductance, i.r., electronic spectra and magnetic measurements. The ligand forms ML complexes with CuII and HgII and ML2 with NiII, ZnII and PdII, where L is the uninegatively charged bidentate ligand and binds through the ring nitrogen and thiocarbonyl sulphur atoms. 相似文献
117.
Pedro de Lima Neto Mohamed Atik Luis A. Avaca Michel A. Aegerter 《Journal of Sol-Gel Science and Technology》1994,1(2):177-184
ZrO2 coatings deposited on 316 L stainless steel sheets were synthesized by sol-gel method using Zr(OC3H7)4 as precursor and isopropanol, glacial acetic acid, and water as solvents for application with ultrasounds. Different solutions for dip-coating were prepared with compositions varying between 0.025 and 0.9 mol/dm3 of ZrO2. X-ray diffraction shows that the films densified at 800°C are crystalline with a tetragonal structure. The thickness of the coatings varied from 0.35–0.75 m. The influence of the ZrO2 coatings on the corrosion behavior of stainless steel substrates in aqueous NaCl was studied through potentiodynamic polarization curves at 1 mV/s. The values of the electrochemical parameters allow for an explanation of the role of the films in the increased resistance of steel against corrosion in moderately aggressive environments. 相似文献
118.
Two new lanthanide complexes of isonicotinic acid N-oxide (HL), namely [Ln(L)2(H2O)4]n·(NO3)n·n(H2O) for Ln = Sm or Tb, have been synthesized and characterized by spectroscopic and crystallographic methods. IR spectra suggest that isonicotinic acid N-oxide acts as a O,O′-bidentate ligand, the N-oxide group as well as the nitrate group are not involved in coordination. Single crystal analyses have shown that both complexes are isomorphous, where the Ln(III) centers are eight coordinated by four O atoms of four water ligands and other four O atoms of two isonicotinic acid N-oxide ligands. The carboxylate groups are only involved in the bidentate syn–syn bridging mode into infinite chains. Hydrogen bonds between aqua ligands, lattice molecules, nitrate and N-oxide groups are formed giving a three-dimensional network. 相似文献
119.
Two hydrophobic vinyl saccharide monomers based on D ‐glucose and D ‐fructose were polymerized by employing the reversible addition‐fragmentation transfer (RAFT) miniemulsion polymerization technique to prepare well‐designed glycopolymers. Three dithiobenzoate‐RAFT agents [S?C(Ph)S? R], 1‐phenylethyl dithiobenzoate (PED), 2‐phenylprop‐2‐yl dithiobenzoate (PPD), and 2‐cyanoprop‐2‐yl dithiobenzoate (CPD), were used to control the growth of polymer chains. The best results were obtained in the presence of the PPD‐RAFT agent and the formed polymers have polydispersity index's (PDI) lower than 1.15. Under adequate miniemulsion polymerization conditions, a glycopolymer with PDI of 1.1 and molecular weight of 5 × 104 g/mol has been successfully synthesized in a short reaction time of 100 min. Furthermore, some block copolymers containing saccharide segment with butyl or methyl methacrylate were prepared. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
120.
A novel monolithic stationary phase having long alkyl chain ligands (C17) was introduced and evaluated in capillary electrochromatography (CEC) of small neutral and charged species. The monolithic stationary phase was prepared by the in situ copolymerization of pentaerythritol diacrylate monostearate (PEDAS) and 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) in a ternary porogenic solvent consisting of cyclohexanol/ethylene-glycol/water. While AMPS was meant to support the electroosmotic flow (EOF) necessary for transporting the mobile phase through the monolithic capillary, the PEDAS was introduced to provide the nonpolar sites for chromatographic retention. Monolithic columns at various EOF velocities were readily prepared by conveniently adjusting the amount of AMPS in the polymerization solution as well as the composition of the porogenic solvent. The monolithic stationary phases thus obtained exhibited reversed-phase chromatography behavior toward neutral solutes and yielded a relatively strong EOF. For charged solutes (e.g., dansyl amino acids), nonpolar as well as electrostatic interaction/repulsion with the monoliths were observed in addition to electrophoretic migration. Therefore, for charged solutes, selectivity and migration can be readily manipulated by changing various parameters including the nature of the monolith and the composition of the mobile phase (e.g., pH, ionic strength and organic modifier). Ultrafast separation on the time scale of seconds of 17 different charged and neutral pesticides and metabolites were performed using short capillary columns of 8.5 cm x 100 microm ID. 相似文献