Unsymmetrical secondary and tertiary phosphines and their derivatives

Conclusions Previously unknown secondary and tertiary phosphines with various functional groups have been obtained and described.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 414–415, February, 1967.     

Unsymmetrical azaporphyrins. Synthesis,structure, and properties

Given are data on the synthesis and spectral and other physicochemical properties of unsymmetrically substituted azaporphyrins containing peripheral fused benzene and sulfur- or nitrogen-containing rings or phenyl substituents.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 11, 2004, pp. 1912–1928.Original Russian Text Copyright © 2004 by Maizlish, Kulinich, Shaposhnikov.This revised version was published online in April 2005 with a corrected cover date.     

Synthesis of Symmetrical and Unsymmetrical Ureas Using Unsymmetrical Diaryl Carbonates

Appropriately substituted unsymmetrical diaryl carbonates react smoothly with primary amines to give the carbamates derived by nucleophilic displacement of the less electron rich aromatic substituent. Subsequent treatment of the carbamates with primary and secondary amines gives either symmetrical or unsymmetrical ureas in excellent yield and the overall process can be carried out as a “one pot” operation. Acetonitrile is the preferred solvent and addition of DBU facilitates the carbamate → urea transformation.     

Unsymmetrical tetraarenoporphines

Zinc complexes of unsymmetrical tetraarenoporphines and their oxidized forms were synthesized by condensation of mixtures of phthalic and naphthalene-2,3-dicarboxylic acid imides with sodium acetate or malonic acid in the presence of zinc acetate. Metal-free compounds were obtained by treatment of benzene solutions of the zinc complexes with gaseous hydrogen chloride. The electronic, PMR, x-ray electron, IR, and mass spectra of the synthesized compounds are discussed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1351–1357, October, 1988.     

Unsymmetrical (R)PNP(R') pincer ligands and their group 10 complexes

Two new unsymmetrical (R)PNP(R')-type pincer ligands based on a bis(tolyl)amine framework have been synthesized and characterized by a variety of techniques, including X-ray crystallography. These ligands have been coordinated to Ni, Pd, and Pt precursors to provide a number of well-characterized group 10 halides. Conversion of these metal halides to metal hydrides was accomplished using borohydride reagents, or by direct interaction of the ligand with the zerovalent metal precursor. The insertion of oxygen into these hydrides in an attempt to prepare metal hydroperoxides has been examined; however, we were unable to obtain stable and isolable hydroperoxide species.     

Unsymmetrical Pentoxy-Substituted Porphyrazines

The reactions of 3,6-dipentoxyphthalonitrile (A) in the 1-pentanol - magnesium pentylate medium with phthalonitrile, 2,3-di(methylsulfanyl)-2-butenedinitrile, and 2,3-dihydro-1,4-dithiin-5,6-dicarbonitrile (B) were performed. Unsymmetrically substituted porphyrazines A₃B were prepared and studied. The influence of the structure of fragment B on the spectral characteristics of the porphyrazines was examined.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 3, 2005, pp. 504–508.Original Russian Text Copyright © 2005 by Nikolaev, Kudrik, Kulinich, Shaposhnikov.     

Unsymmetrical fluorine-containing disulfides

Russian Chemical Bulletin -     

Unsymmetrical Pyridoxal-Based Bisazomethines

Russian Journal of General Chemistry - The reaction of equimolar amounts of pyridoxal and 1,2-propylenediamine leads to the formation of monoimine, which exists as a cyclic imidazolidine tautomer....     

Oxazoloanthrapyridines and their properties

Acylation of 1-aminoanthrapyridones gives oxazoloanthrapyridines, for which reactions with opening of the oxazole ring are characteristic: 1-acylaminoanthrapyridones are formed in acid and alkaline hydrolysis, while 1-anthrapyridonylamidines and 1-anthrapyridonylimino esters, respectively, are formed by the action of amines and alkoxides. Similarly, dioxazoloanthradipyridines, which have similar properties, are formed from 1,8-diaminoanthra [1,9-4, 10]- and 1,7-diaminoanthra[1,95,10] dipyridones. Problems associated with the mechanism of formation of the oxazoloanthrapyridines are examined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 610–616, May, 1973.     

Aryloxypentachlorocyclotriphosphazenes and their properties

Compounds of the general formula N₃P₃Cl₅(OC₆H₄-4-R), where R = H, F, Cl, CH₃, or OCH₃, have been prepared under anhydrous conditions. The cyclic trimers were characterized by IR spectroscopy, mass spectrometry and elemental analysis. IR data indicated that both chloro and aryloxy groups are bonded to the phosphorus atoms of the N₃P₃ ring. The mass spectra of the various compounds were found to be similar with the loss of the aryloxy group the dominant fragmentation process. Each spectrum exhibited a molecular ion peak and no evidence was found for contamination by other partially substituted aryloxychlorocyclotriphosphazenes. Elemental analysis further verified the general formula N₃P₃Cl₅(OC₆H₄-4-R) for each of the compounds.     

Unsymmetrical Sandwich Diphthalocyanine and Similar Complexes

Data on the synthesis and spectral and physicochemical properties of unsymmetrical sandwich diphathalocyanine and similar complexes are presented.     

Unsymmetrical, oxazolinyl-containing achiral and chiral NCN pincer ligand precursors and their complexes with palladium(II)

The unsymmetrical, achiral and chiral NCN pincer ligand precursors (3a-3d) with oxazoline and pyrazole as N donors as well as (3e) which has oxazolinyl and amino group have been synthesized in a facile manner in four steps starting from commercially available isophthalaldehyde. Direct C2 metallation of the precursors (3a-3e) with Pd(OAc)₂ in refluxing HOAc, followed by treatment with LiCl at room temperature provided convenient access to the corresponding pincer palladium(II) complexes (4a-4e). The molecular structure of complex 4e has been determined by X-ray single-crystal diffraction. The obtained Pd complexes exhibited good activities in the Suzuki reactions of aryl bromides and activated aryl chlorides with phenylboronic acid.     

Microporous carbons and their properties

Thermal degradation of saw dust impregnated with phosphorus-and nitrogen-containing solution with ammonium, lithium, and cesium additives in the 20–700°C range was studied by physicochemical methods. The conditions of preparing activated carbon were determined and its adsorption and structural characteristics were studied.     

Waterborne polyurethanes and their properties

Anionomer-type waterborne polyurethanes (PUs) were obtained from poly(β-methyl-δ-valerolactone) glycol (PMVL) and isophorone diisocyanate, following a prepolymer mixing process. The soft-hard segment phase separation in response to the variations of composition and structure of PU has been studied from the dynamic mechanical measurements of the emulsion cast films. The structural variation included ionic and hard segment content, molecular weight of NCO-terminated prepolymer, and type and length of the soft segment. It was found that phase separation is more sensitive to the soft segment length, rather than the soft segment content. With only phase separation, the rubbery modulus was significant even with lower hard segment content. Phase separation was much more pronounced with PU from poly(tetramethylene adipate) glycol, rather than from PMVL and poly(caprolactone) © 1996 John Wiley & Sons, Inc.     

Alternant systems and their properties

Neutral, ionic, and complete alternant systems are studied using the alternancy symmetry adapted (ASA ) approach. This approach is based on an explicit construction of ASA operators that are up to the sign invariant with respect to the particle-hole symmetry transformation. These operators serve as building blocks of alternant systems, and they determine their characteristic properties. All Hamiltonians describing neutral alternant systems are explicitly constructed. Up to some minor restrictions, all Hamiltonians describing ionic and complete alternant systems are also explicitly constructed. Inversely, given a Hamiltonian ? in a second quantization notation, one can easily check whether or not this Hamiltonian describes a neutral (ionic, complete) alternant system. All linear properties characteristic to neutral (ionic, complete) alternant systems are obtained. In particular, all one- and two-particle properties are derived in an explicit form. The properties obtained substantially generalize “classical” properties of alternant systems such as, in the case of neutral alternant systems, uniform charge density distribution, vanishing bond orders between atomic sites of the same parity, and alternancy selection rules for the electric dipole transitions.     

Organozeolite materials and their properties

Attempts in developing organozeolites, namely microporous and mesoporous crystalline inorganic-organic composites with a zeolite-like three-dimensional framework and organic moieties covalently connected to the framework, are briefly reviewed. MCM-41 type mesoporous materials modified by organic functional groups have been prepared by use of organosiloxane as a part of Si sources and by post-modification of the purely inorganic materials using organosiloxane. Also, the incorporation of organic moieties into the zeolite frameworks has been tried. Recently, several novel metal organophosphonates with a three-dimensional framework, which can be regarded as organozeolites, have been prepared. Along with these new attempts, the authors' studies in preparation, structural analysis and gas adsorption properties of microporous aluminomethylphosphonates are introduced.     

Unsymmetrical β-diketones, monothio-β-diketones and their nickel(II) and cobalt(III) complexes

Summary Unsymmetrically substituted β-diketones, RCOCH₂COR′ (R and R′ = aryl) have been synthesized and used to prepare their monothio-β-diketone derivatives. Because of the similar basicities of the carbonyl oxygen due to the electronic effects of the R and R′ groups, a mixture of the monothio-β-diketones, RCSCH₂COR′ and R′CSCH₂-COR, is formed. Several of the monothio-β-diketones have been used to prepare their corresponding Ni^II and Co^II complexes. Mass spectral and ¹³C-n.m.r. data are used to confirm the formation of isomers of the monothio-β-diketonate ligands and their metal complexes.     

New Bromine-Containing Symmetrical and Unsymmetrical Cage Phosphonates

Russian Journal of General Chemistry - As a result of brominating of symmetrical and unsymmetrical cage phosphonates, new mono- and dibromo-containing derivatives were obtained. Composition and...