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Amine Nitrogen (amine + nitrogen)
Selected AbstractsOne-Dimensional Coordination Polymers of MnII, CuII, and ZnII Supported by Carboxylate-Appended (2-Pyridyl)alkylamine Ligands , Structure and MagnetismEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 22 2009Himanshu Arora Abstract Four new complexes [MnII(L1OO)(H2O)][ClO4]·2H2O (1), [ZnII(L1OO)][ClO4]·2H2O (2), [CuII(L3OO)][CF3SO3]·H2O (3), and [ZnII(L3OO)][ClO4] (4) (L1OO, = 3-[(2-(pyridine-2-yl)ethyl){2-(pyridine-2-yl)methyl}amino]propionate; L3OO, = 3-[(2-(pyridine-2-yl)ethyl){(dimethylamino)ethyl}amino]propionate) have been synthesized and characterized by elemental analysis, IR, and UV/Vis spectroscopy. Structural analysis revealed that 1, 3, and 4 are one-dimensional chain-like coordination polymers. In 1 distorted octahedral MnN3O3 and in 3 square-pyramidal CuN3O2 coordination is satisfied by three nitrogen atoms and an appended carboxylate oxygen atom of the ligand, and an oxygen atom belonging to the carboxylate group of an adjacent molecule. In 4 trigonal bipyramidal ZnN3O2 coordination environment is provided by two nitrogen atoms and an appended carboxylate oxygen atom of the ligand in the equatorial plane, and the two axial positions are satisfied by a tertiary amine nitrogen and an oxygen atom belonging to the carboxylate group of an adjacent molecule. In 1 the MnII center is coordinated by an additional water molecule. In these complexes each monomeric unit is sequentially connected by syn - anti carboxylate bridges. Temperature-dependent magnetic susceptibilities for 1 and 3 are measured, revealing antiferromagnetic interactions through syn - anti carboxylate bridges between the MII centers. Analysis of the crystal packing diagram reveals that in 1 extensive ,,, stacking involving alternate pyridine rings of adjacent 1D chain exists, which eventually lead to the formation of a 2D network structure. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Synthesis of (E)-3-Alkylidene-1-pyrrolines by the Rhodium- Catalyzed Cyclization of Terminal Alkynes with Homopropargylic AminesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14-15 2009Yoshiya Fukumoto Abstract The cyclization of terminal alkynes with homopropargylic amines in the presence of a rhodium complex as catalyst leads to the formation of (E)-3-alkylidene-1-pyrrolines. The reaction tolerates a wide range of functional groups on the terminal alkynes. The formation of a vinylidene-rhodium complex, followed by the intermolecular nucleophilic attack of a homopropargylic amine nitrogen on the ,-carbon atom of the vinylidene-rhodium complex, is proposed as a key step in the catalytic reaction. [source] Proton transportation in an organic,inorganic hybrid polymer electrolyte based on a polysiloxane/poly(allylamine) networkJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 15 2005Ping-Lin Kuo Abstract A new class of proton-conducting polymer was developed via the sol,gel process from amino-containing organic,inorganic hybrids by the treatment of poly(allylamine) with 3-glycidoxypropyltrimethoxysilane doped with ortho -phosphoric acid. The polymer matrix contains many hydrophilic sites and consists of a double-crosslinked framework of polysiloxane and amine/epoxide. Differential scanning calorimetry results suggest that hydrogen bonding or electrostatic forces are present between H3PO4 and the amine nitrogen, resulting in an increase in the glass-transition temperature of the poly(allylamine) chain with an increasing P/N ratio. The 31P magic-angle spinning NMR spectra indicate that three types of phosphate species are involved in the proton conduction, and the motional freedom of H3PO4 is increased with increasing P/N ratios. The conductivity above 80 °C does not drop off but increases instead. Under a dry atmosphere, a high conductivity of 10,3 S/cm at temperatures up to 130 °C has been achieved. The maximum activation energy obtained at P/N = 0.5 suggests that a transition of proton-conducting behavior exits between Grotthus- and vehicle-type mechanisms. The dependence of conductivity on relative humidity (RH) above 50% is smaller for H3PO4 -doped membranes compared with H3PO4 -free ones. These hybrid polymers have characteristics of low water content (23 wt %) and high conductivity (10,2 S/cm at 95% RH), making them promising candidates as electrolytes for fuel cells. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3359,3367, 2005 [source] Mass spectral studies on aryl-substituted N -carbamoyl/N -thiocarbamoyl narcotine and related compoundsRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 10 2002Shefali Aggarwal Positive ion mass spectral fragmentation of new N-carbamoyl/N-thiocarbamoyl derivatives of narcotine and compounds closely related to it are reported and discussed. The techniques used include electron impact (EI), fast-atom bombardment (FAB), matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) and electrospray ionization tandem mass spectrometry (ESI-MS/MS). Prominent peaks in the mass spectra of these compounds appear to involve C-C bond cleavage , to the amine nitrogen with loss of the 4,5-dimethoxy(1H)isobenzofuranone moiety from their molecular ions, along with another prominent peak at m/z 382. No molecular ion peaks of these compounds were recorded in EI, whereas intense [M,+,H]+ ion peaks were observed in FAB and ESI spectra. MALDI also yielded [M,+,H]+ ion peaks in good agreement with FAB and ESI studies. Copyright © 2002 John Wiley & Sons, Ltd. [source] Two novel molybdenum complexes containing [Mo2O2S2]2+ fragment: synthesis, crystal structures and catalytic studiesAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 12 2007Jun-Feng Wu Abstract Mo2O2S2(HGly)(Gly)21 and K6[Mo2O2S2(nta)2][Mo2O2S2(ntaH)2]·4H2O 2 were synthesized by the reactions of (NH4)2MoS4 and amino acids L (L = glycine, nitrilotriacetic acid) in ethanol,water medium at ambient temperature. The two complexes were characterized by elemental analysis, infrared spectra, UV,visible spectra, TG,DTA and XPS. X-ray crystallographic structural analyses revealed that compound 1 is a binuclear MoSglycinate complex, a glycinate ligand is coordinated to each molybdenum atom through its amine nitrogen and carboxylato oxygen, respectively, and the third glycinate acts as a bridge through its two carboxylato oxygens linking the two molybdenum atoms. Compound 2 is also a binuclear MoS complex with two nitrilotriacetate ligands, each of which is coordinated to a molybdenum atom via its two ,-carboxylato oxygens and a nitrogen atom. Simultaneously, each molybdenum atom in 1 and 2 is chelated to a terminal oxygen and two bridging sulfurs to complete the octahedral configuration. Their catalytic activities in the reduction from C2H2 to C2H4 as well as other binuclear MoSpolycarboxylate complexes, a [Fe4S4] single cubane and a chainlike MoFeS compound were investigated and it was found that 1 exhibited relatively good catalytic activity. Copyright © 2007 John Wiley & Sons, Ltd. [source] Synthesis and solution properties of a new pH-responsive polymer containing amino propanesulfonic acid residuesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 1 2003Sk. Asrof Ali Abstract The reaction of diallyl amine with 1,3-propane sultone led to the synthesis of the zwitterionic monomer 3-(N,N -diallylammonio)propanesulfonate. The sulfobetaine was cyclopolymerized in water in the presence of sodium chloride with t -butylhydroperoxide as an initiator to afford a polysulfobetaine (PSB) in very good yield. PSB, upon treatment with sodium hydroxide, was converted into an anionic polyelectrolyte (APE). Although APE was readily soluble in salt-free water, PSB needed the presence of low-molecular-weight salts (e.g., NaCl, KI, etc., in the range of 0.135,1.04 N) for its dissolution. The solution properties of PSB and APE were investigated with potentiometric and viscometric techniques. The basicity constant of the amine was apparent and followed the modified Henderson,Hasselbalch equation; as the degree of protonation (,) of the whole macromolecule increases, the protonation of the amine nitrogens becomes increasingly more difficult. The composition and phase diagram of the aqueous two-phase systems of APE/PSB and poly(ethylene glycol) were also explored. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 172,184, 2003 [source] Separation and measurement of plant alkaloid enantiomers by RP-HPLC analysis of their Fmoc-Alanine analogs ,PHYTOCHEMICAL ANALYSIS, Issue 5 2008Stephen T. Lee Abstract Introduction. Ammodendrine (1), anabasine (2) and coniine (3) can cause congenital malformations in livestock. They appear naturally in both enantiomeric forms, and can cause variable physiological responses. A method to measure the enantiomeric ratio of these natural toxins is needed. Objective. To develop a simple and economical method in order to determine the enantiomeric ratios of piperidine and pyrrolidine alkaloids in small samples of plant material. Methodology. Mixtures of isolated or purified plant alkaloids were converted to their Fmoc- l -Ala-alkaloid analogues forming diastereomeric mixtures, which were then analysed by high pressure liquid chromatography (HPLC) with mass spectrometry (MS) and ultraviolet (UV) detection to determine enantiomeric ratios. Results. The diastereomeric analogs for ammodendrine, anabasine and nornicotine could be separated and the enantiomeric ratios determined. The Fmoc- l -Ala-coniine analogue was not resolved under the HPLC conditions studied. The enantiomeric ratios of the selected plant alkaloids were measured and found to differ between both location within a species and location between species. Conclusion. A low-cost HPLC method to analyse the enantiomeric ratio of plant alkaloids containing primary or secondary amine nitrogens via conversion to their respective diastereomeric analogues has been developed. Published in 2008 by John Wiley & Sons. [source] 15N NMR spectroscopy as a method for comparing the rates of imidization of several diamines,POLYMER COMPOSITES, Issue 6 2006James C. Johnston The relative rates of the conversion of amide-acid to imide were measured for a series or aromatic diamines that have been identified as potential replacements for 4,4,-methylene dianiline (MDA) in high-temperature polyimides and polymer composites. These rates were compared with the 15N NMR resonances of the unreacted amines. The initial rates of imidization track with the difference in chemical shift between the amine nitrogens in MDA and those in the subject diamines. This comparison demonstrated that 15N NMR spectroscopy is appropriate for the rapid screening of candidate diamines to determine their reactivity relative to MDA, and can serve to provide guidance to the process of creating the time,temperature profiles used in processing these materials into polymer matrix composites. POLYM. COMPOS. 27:723,729, 2006. © 2006 Society of Plastics Engineers [source] | |||||||||||||