Search results for "ionic"

Nucleophilic attack by 2-pyridylpalladium(II) and platinum(II) complexes on the organic chlorides ClCH2R (R  COMe, CN, Ph, Cl)

1992

Abstract The 2-pyridyl complexes trans-[MCl(C5H4NC2)(PPh3)2] (M = Pd, 1a; M = Pt, 1b), [MCl(C5H4NC2)(dppe)] (M = Pd, 2a; M = Pt, 2b) and [M(dmtc)(C5H4NC2) (PPh3)] (M = Pd, 3a; M = Pt,3b) react with the chlorides ClCH2R(R  COMe, CN, Ph) to give cationic products containing the 2-pyridylium ligands (1-CH2R)C5H4NC2. The rate of nucleophilic displacement of the chloride ion from ClCH2R depends on the central metal (Pt > Pd), on the coordination geometry (1 ~ 3) and on the substituent R (COMe > CN > Ph for the reactions with 3b). Like 1b and 2b, complex 3b also reacts with dichloromethane to give [Pt(dmtc){(1-CH2Cl)C5H4NC2}(PPh3)]+. The reaction of the binuclear compound [{PdCl(μ-C5H4NC2,…

Silicatein conjugation inside nanoconfined geometries through immobilized NTA–Ni(ii) chelates

2013

The chemical modification and bioconjugation processes inside confined geometries by His-tagged silicatein promote sensitive changes in the polarity and surface charge density that mainly contribute to the ionic current rectification properties of the single conical nanopores.

Growth of polyoxymethylene crystals during cationic polymerization of trioxane in nitrobenzene

1973

Aminolysis of monoacetyl derivatives of 2,2′ -dihydroxydiphenylmethanes

1974

A neighboring group effect was found for the aminolysis of the second acetyl group in acetates of 2,2′-dihydroxydiphenylmethane derivatives containing a nitrophenol and a methylphenol unit. Kinetic measurements with an excess of n-butylamine in dioxane were done with 2-(2-hydroxy-3, 5-dinitrobenzyl)-4-methylphenyl acetate (1), 2-(2-hydroxy-5-nitro-benzyl)-4-methylphenyl acetate (2), and 2-(2-hydroxy-3-nitro-5-methylbenzyl)-4-methyl-phenyl acetate (3). The maximum rate was found for compound 2. When the concentration of n-butylamine was varied over a large range, the results obtained for compound 2 could be explained best, by assuming that the acetyl group in the methylphenol unit is aminoli…

1993

Hexachlororhenate(IV) salts of organic radical cations

2005

Abstract The ionic salts ( p -rad) 2 [ReCl 6 ] ( 1 ) and ( m -rad) 2 [ReCl 6 ] ( 2 ) ( p / m -rad = 2-(4/3- N -methylpyridinium)-4,4,5,5-tetramethyl-4,5-dihydro-1 H -imidazol-1-oxyl-3- N -oxide) have been prepared and their crystal structures determined by single-crystal X-ray diffraction. The nitronyl nitroxide cations in compound 1 show a layered disposition, whereas the [ReCl 6 ] 2− units are placed between these layers. The nitronyl nitroxide cations in compound 2 adopt an hexagonal array but they do not result in layers. Bulk magnetic properties of 1 and 2 have been investigated in the temperature range 2–300 K. Both compounds show weak but significant intermolecular antiferromagnetic …

Polyoxometalate salts of cationic nitronyl nitroxide free radicals

2008

The cationic nitronyl nitroxide free radical of the N-methylpyridinium type p-MepyNN + has been combined with [Mo 8 0 26 ] 4- and Keggin [SiW 12 0 40 ] 4- polyanions to afford salts ( p-MepyNN) 4 [Mo 8 0 26 ] DMSO (DMSO = dimethylsulfoxide) (1) and (p-MepyNN)4[SiW 12 0 40 ] 6DMF (DMF = dimethylformamide) (2). Herein, their structural and magnetic properties are described.

Layered ferromagnets hosting tetraalkylammonium-substituted nitronyl nitroxide free radicals

2008

This paper describes the structural, magnetic and EPR properties of hybrid organic/inorganic magnets formed by anionic heterometallic oxalato-based layers and cationic nitronyl nitroxide (NN) free radicals of the tetraalkylammonium type. A series of compounds of formula nBu3NCH2NN[MCr(ox)3] (M = Mn (1), Ni (2), Zn (3)) has been prepared and studied by AC and DC magnetic susceptibility measurements and EPR spectroscopy. Magnetic order with critical temperatures ranging from 5 K to 15 K was confirmed. EPR measurements show that the organic spin carriers interact significantly with the inorganic network.

Star-Like Polymers of tert -Butyl Acrylate via Controlled Radical Polymerization - Synthesis and Properties

2011

Summary: Star polymers with different numbers and lengths of poly(tert-butyl acrylate) arms were obtained by the core-first method via atom transfer and iodine mediated radical polymerization. Multifunctional initiators with different numbers of initiating groups (from 3 to 28) were used to initiate the polymerization of tert-butyl acrylate, yielding stars with different numbers of arms. The structures of the stars were characterized by NMR and gel permeation chromatography with refractive index, multiangle laser light scattering and viscosimetric detectors.

Tailored Semiconducting Polymers: Living Radical Polymerization and NLO-Functionalization of Triphenylamines

2002

This paper describes the preparation of various polymers with triarylamine side groups. High molecular weight materials were obtained by free radical polymerization utilizing the gel effect. Polymers with a marrow polydispersity and a predetermined molecular weight could be prepared by living radical polymerization. The T g could, thereby, be controlled between 50 and 140°C either by using different monomers or by varying the molecular weight. Living radical polymerization allowed in addition the preparation of block copolymers. The triarylamine side groups could be transformed into NLO-chromophores by reaction with tetracyanoethylene. This leads to the incorporation of tricyanoethylene. Th…