Mixed Phenyl Research Articles

Mixed Phenyl and Thiophene Oligomers for Bridging Nitronyl Nitroxides.

The synthesis of four nitronyl nitroxide (NN) biradicals is described which are conjugatively linked through p-ter-phenyl (PPP), ter-thiophene (TTT) and alternating phenylene (P) and thiophene (T) units as PTP and TPT. We first utilized Suzuki and Stille coupling reactions through protection and deprotection protocols to synthesize these (NN) biradicals. Single crystals were efficiently grown for radical precursors of 3, 5, 6, PPP-NNSi, PTP-NNSi, and final biradicals of TTT-NN, TPT-NN, and PPP-NN, whose structures and molecular packing were examined by X-ray diffraction studies. As a result, much smaller torsions between the NN and thiophene units (∼10°) in TTT-NN and TPT-NN than for NN and phenyl units (∼29°) in PPP-NN were observed due to smaller hindrance for a five vs a six membered ring. All four biradicals TTT-NN, TPT-NN, PTP-NN, and PPP-NN were investigated by EPR and optical spectroscopy combined with DFT calculations. The magnetic susceptibility was studied by SQUID measurements for TTT-NN and TPT-NN. The intramolecular exchange interactions for TPT-NN and TTT-NN were found in good agreement with the ones calculated by broken symmetry DFT calculations.

A Novel Approach Toward the Synthesis and Characterization of Pyrimidyl Chalcogen Compounds

A variety of hitherto unknown symmetrical and unsymmetrical pyrimidyl chalcogen compounds have been synthesized and characterized by elemental analysis using various spectroscopic techniques viz. NMR 1 H, 13 C, 77 Se and infrared. Two different methodologies were employed. The first method involves the use of hydrazine hydrate as reducing agent to generate dichalcogenide anions followed by reaction with 2, 4-dichloropyrimidine to give the dichalcogenide compounds in good yield. The second method employs chlorine-magnesium exchange of 2,4-dichloropyrimidine using iso propyl magnesium chloride. The synthesis of the mixed phenyl pyrimidyl selenides have been achieved using sodium borohydride in ethanol as a reductive reagent to cleave Se-Se bond followed by alkylation with 2-chloro-4, 6-dimethylpyrimidine and 2, 4-dichloropyrimidine.

The catalytic dimerization of acrylonitrile: III. Activity and selectivity of homogeneous catalysts derived from substituted aromatic phosphinites and phosphonites

The incorporation of electron-releasing substituents into the para-positions of alkyl diarylphosphinites, Ar 2POR, and dialkyl arylphosphonites, ArP(OR) 2, causes a marked increase in the rate of reaction compared with that of the unsubstituted derivatives in the catalysis of the linear dimerization of acrylonitrile in toluene/alcohol solution. The magnitude of the effect is approximately proportional to the electron-releasing capability of the substituent. This enhancement in rate is offset by an associated reduction in the selectivity to the desired linear dimer. However, optimisation of reaction conditions provides a satisfactory combination of rate and selectivity. In contrast, when electron-withdrawing substituents are incorporated into the ortho position of the aryl ring, there are distinct disadvantages in that the rate of dimerization is significantly reduced and the selectivity to the linear dimer is unacceptably low. The most promising catalysts, from both rate of reaction and selectivity considerations, are the bis- p-tolylphosphinite, ( p-MeC 6H 4) 2POPr i, the mixed phenyl p-methoxyphenylphosphinite, ( p-MeOC 6H 4)PhPOPr i at 60°C, and the bis- p-methoxyphenylphosphinite, ( p-MeOC 6H 4) 2POPr i at 20°C.

Cleavage of phosphorus–phenyl and phosphorus-2-pyridyl bonds in the reactions of mixed phenyl-(2-pyridyl) phosphines with [Ru3(CO)12

The compound [Ru3(CO)12] reacts at room temperature in tetrahydrofuran with tri(2-pyridyl)phosphine, P(2-C5H4N)3′ when catalysed by [N(PPh3)2]Cl, to give a product derived by cleavage of a phosphorus-2-pyridyl bond, [Ru3(µ-2-C5H4N){µ3-P(2-C5H4N)2}(CO)9]1. No simple substitution compounds could be isolated. The likely intermediates [Ru3(CO)n{P(2-C5H4N)3}](n= 10 and/or 11) spontaneously decarbonylate while a 2-pyridyl group migrates from phosphorus to ruthenium atoms. A similar reaction using phenyldi(2-pyridyl) phosphine, PPh(2-C5H4N)2′ leads to the competitive transfer of 2-pyridyl and pheyl groups to give almost equal quantities of two products, [Ru3(µ-2-C5H4N){µ3-PPh(2-C5H4N)}-(CO)9] and [Ru3(µ-PhCO){µ3-P(2-C5H4N)2}(CO)9]. The crystal structure of 1 shows that the 2-pyridyl group that has migrated bridges two ruthenium atoms with no Ru-Ru bond between them and that the di(2-pyridyl) phosphido ligand is triply bridging with one nitrogen co-ordinated and one free. As in the reported reaction of [Ru3(CO)12] with PPh2(2-C5H4N) to give [Ru3(µ-PhCO){µ3-PPh(2-C5H4N)}(CO)9], the reason why P-C bond cleavage occurs under remarkably mild conditions and the mechanism of the processes have still to be determined.

Synthesis of phenyl(perfluoroorgano)mercury derivatives C 6H 5Hg(R f) [R f = C nF 2n + 1 ( n = 1–4 or 6) or C 6F 5] by the reactions of bis(perfluoroorgano)cadmium compounds with phenylmercury chloride

The mixed phenyl(perfluoroorgano)mercury derivatives C 6H 5Hg(R f) [R f = C nF 2n+1 ( n = 1–4 of 6), C 6F 5] have been prepared by reactions of C 6H 5HgCl with Cd(R f) 2 compounds, and their 19F NMR, 199Hg and (in some cases) 13C NMR spectra and mass spectra recorded.

Electronic and steric effects in the dissociative displacement of thioethers from mixed phenyl(thioether)platinum(II) complexes

A series of compounds of the types cis-[PtPh 2 L 2 ], where L encompasses a wide range of thioethers of different steric and electron-donating characteristics, have been prepared and characterized. Most of these monomeric compounds exist in solution in equilibrium with the sulfur-bridged dimer [Pt 2 Ph 4 (μ-L) 2 ] and the free thioether. Addition of small amounts of ligand in solution allows the stabilization of the monomeric form

Reactions of titana- and zircona-cyclopentadienes with alkynes

Expanded metallacycles of up to 17 members have been obtained from insertion reactions of acetylenic molecules into the M–C bonds of various substituted dicyclopentadienyl-titana- and -zircona-cyclopentadienes; in one case, a zirconacyclononatetraene with mixed phenyl and methyl substituents was isolated.

Group 4 organometallic compounds. Part 8. Preparation and Mössbauer spectra of five- and six-co-ordinate di- and tri-organotin compounds containing mixed phenyl and butyl groups on tin

Mossbauer spectroscopic data and preparative details are reported for a range of [SnIVBuPh], [SnIVBu2Ph], and [SnIVBuPh2] compounds. The stereochemical preferences of the butyl and phenyl groups in octahedral and trigonal-bipyramidal co-ordination in these mixed-ligand complexes, relative to their symmetrical analogues, have been examined on the additivity model, with comparison between theory and experiment based on our previously reported data on ligand partial quadrupole splittings. For the derivatives of the two triorganotins, trends in centre shift (c.s.) and quadrupole splitting (q.s.) parameters are reported, which are consistent with the additivity model. An approximate inverse correlation has been noted between q.s. and element–oxygen stretching frequency in comparing complexes of [SnBuxPh3–x](x= 0, 1, or 2) with PPh3O and AsPh3O.

Organosubstituted phosphazenes. Part 9. Mass spectra of phenyl-substituted chlorocyclophosphazenes

Mass-spectral data for a series of phenylcyclotri-λ5-phosphazenes, N3P3PhnCl6-n(n= 2–4 or 6), and isomeric tetrachlorotetraphenylcyclotetra-λ5-phosphazenes, N4P4Ph4Cl4, of known structure are reported and discussed. Particular attention has been directed to developing correlations between fragmentation pattern and structure. Differentiation of molecules with diphenyl-substituted phosphorus atoms and molecules with mixed phenyl- and chloro-substituted phosphorus atoms is most clearly demonstrated in the tendency of the former derivatives to exhibit loss of hydrogen atoms and for the latter to undergo ready loss of chlorine atoms. Rearrangements, especially in the tetrameric series, make structural assignments based on low-mass fragments unreliable. With the aid of these correlations, the structure of a trace product from the reaction of MgBrPh and N4P4Cl8 has been assigned from the mass-spectral data.

Quantum efficiency of the 2537 A. Photolysis of a mixed phenyl–methyl polysiloxane

AbstractThe ultraviolet (λ = 2537 A.) photolysis of a degassed mixed phenyl and methyl polysiloxane liquid is examined in terms of gas and crosslinking yields. Results are compared to the published values obtained by ionizing irradiation of this type of molecule. It is shown that ultraviolet radiation is less efficient by two orders of magnitude in producing decomposition (i.e., gaseous products) than is ionizing radiation. The comparisons for crosslinking efficiencies are less certain, but the yields seem to have much more similar values in this case based on a spectroscopic estimation of crosslinking (i.e., analysis for substituted phenylcyclohexadiene formation). The gas quantum yields were ϕH2 = 2.6 × 10−5, ϕCH4 = 0.63 × 10−5, ϕC2H6 ≈ 0.12 × 10−5, and ϕC2H2 ≈ 0.06 × 10−5.

Organo-silicon Chemistry. I. The Mixed Phenyl- and p-Biphenylyl-substituted Silanes, their Physical Properties and Infrared Absorption Spectra1

Organo-silicon Chemistry. I. The Mixed Phenyl- and p-Biphenylyl-substituted Silanes, their Physical Properties and Infrared Absorption Spectra¹

Estimation of Mixed Phenyl and Ethyl Mercuric Compounds

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEstimation of Mixed Phenyl and Ethyl Mercuric CompoundsDorothy Polley and V. L. MillerCite this: Anal. Chem. 1952, 24, 10, 1622–1623Publication Date (Print):October 1, 1952Publication History Published online1 May 2002Published inissue 1 October 1952https://doi.org/10.1021/ac60070a030RIGHTS & PERMISSIONSArticle Views18Altmetric-Citations10LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (257 KB) Get e-Alerts Get e-Alerts

The Synthesis of Some Tertiary Amine Derivatives of Mixed Phenyl Alkyl Sulfides

The Synthesis of Some Tertiary Amine Derivatives of Mixed Phenyl Alkyl Sulfides