H3l23
in which intermolecular complementary hydrogen bonding with two sets of NH-donors and N-acceptors plays pivotal roles Scheme 10 .41'4 Various guest molecules can be included in the cavities of molecular aggregates in the crystals. Another feature of benzimidazole-containing ligands is the ability to tune the redox potential by remote site deprotonation.15'43 The oxidation potential of the Ru complex Ru H2L5 2 2 is sensitive to solution pH.44 This change arises from the proton-coupled electron...
Info Ogf
The tetraphosphine Ph2P 2CHC6H4CH PPh2 2 109 could readily be prepared by nucleophilic reaction of Ph2PCH2C6H4CH2PPh2 with BuLi at -40 C, followed by quenching of the lithiated intermediate with Ph2PCl.225 The same conditions could then be applied to the intermediate triphosphine, affording 109 as an air-sensitive white solid.225 Alternatively, albeit in lower yield, slow addition of LiPPh2 to a,a,a',a'-tetrabromo-p-xylene also gave 109 . The penultimate step in the synthesis of the new...
Synthetic Methods For Benzimidazole Derivatives
Most 2-substituted benzimidazoles have been obtained by the Phillips condensation reaction of o-phenylenediamine with aliphatic or aryl acids either in aqueous mineral acid or in polyphos-phoric acid as a condensing agent.3 Several efficient synthetic routes to substituted benzimidazoles have been reported and are shown in Scheme 3. i Scheme 3 1 . Condensation reactions of o-phenylenediamine with aliphatic or aryl acids can afford the benzimidazole derivatives. This synthetic method was applied...
Nh3
There is a characteristic strongly absorbing ligand-to-metal charge transfer band in the visible region of these complexes' electronic absorption spectra that has been assigned to the cyanamido-Ru111 chromophore. The effect of conjugation on the electronic properties of the cyanamido-Ru111 chromophore was explored by the synthesis and characterization of Ru NH3 5 NCNR 2 , where NCNR is cyanamido, phenylcyanamido, 4-cyanamidobiphenyl, 1-cyanamidonaphthalene, 2-cyanamidonaphthalene,...
Syntheses Of Metal Diketonates
Although the synthesis of a metal -diketonate and its stoichiometry depend largely on the reaction conditions, such as choice of solvent, temperature, and pH of the solution, as well as on the mode of isolation of the pure complex, some general conditions can be outlined.1'2'7'8'61 This method is useful only for electropositive elements such as alkali metals, alkaline earths, and aluminum. Diketones react with these metals, in anhydrous aromatic solvents, with evolution of molecular hydrogen...
Metalcatalyzed Coupling Reactions 11221 Homocoupling of halopyridines
The most useful transition metal-mediated halopyridine homocouplings make use of a Ni0 catalyst,20 most often generated in situ through reduction of a Ni11 complex. This method provides product in much higher yield than the classic Ullmann reaction and is compatible with many functional groups. For example, the chiral bipyridine 8 was generated in 91 yield via Ni-catalyzed homocoupling of the pyridyl chloride, 7 Scheme 1 .21 Reactions that employ
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1. Blau, F. Her. 1888, 21, 1077-1078. 2. Gerdeissen, Her. 1889, 22, 244-254. 3. Waiden, Jr., G. H. Hammett, L. P. Chapman, R. P. J. Am. Chem. Soc. 1931, 53, 3908. 4. Richter, F. Smith, G. F. J. Am. Chem. Soc. 1944, 66, 396-398. 5. Smith, G. F. Cagle, F. W., Jr. J. Am. Chem. Soc. 1947, 69, 781-784. 6. Smith, G. F. Richter, F. P. Phenanthroline and Substituted Phenanthroline Indicators, their Preparation, Properties, and Applications to Analysis G. F. Smith Chemical Co, Columbus, OH, 1944. 7....
Introduction Rtl
The pyridopyridines, also called benzodiazines, and more commonly naphthyridines, consist of a group of diazanaphthalenes with one nitrogen in each ring and none at the bridgehead position. From the six possible isomers, one example of each of the series 1-X and 2-X, and the numbering scheme, are represented in 1 and 2 . The naphthyridines and their derivatives exhibit various types of biological activity, and the organic chemistry has been frequently reviewed.1-6 The preparation of the ligands...