Home  About us  Contact
 

Primary Amine Groups (primary + amine_groups)

Distribution by Scientific Domains
Polymers and Materials Science75%

Selected Abstracts

Oxidation of CH3NH2 and (CH3)2NH by NiIII(cyclam)(H2O)23+ in Aqueous Solutions

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 20 2004
Dror Shamir
Abstract NiII(1,4,8,11-tetraazacyclotetradecane)2+, NiIIL2+, is a good electrocatalyst for the oxidation of CH3NH2 and (CH3)2NH but not of (CH3)3N. The oxidation kinetics of the amines by NiIIIL(H2O)23+ indicate that the amines are good axial ligands to the tervalent nickel complex. The complexes NiIIIL[N(CH3)iH3,i](H2O)3+ are stronger oxidants than the complexes NiIIIL[N(CH3)iH3,i]23+. The oxidation is base-catalyzed and obeys a second-order rate law in NiIIILX2. It is proposed that the key step is NiIII,L(H2O)[N(CH3)iH2,i]2+ + NiIIILX2 , LNiII,N(=CH2)(CH3)i,1H2,i + NiIIL2+ + H3O+ + 2 X. Naturally, N(CH3)3 is not oxidized by this mechanism. Of special interest is the observation that the axial ligands CH3NH2 and (CH3)2NH are oxidized by the central cation, while the cyclam ligand, which has four secondary amine groups bound to the nickel(III) ion, and axially bound pendant primary amine groups, which are covalently linked to the macrocyclic ligand, are relatively stable. This difference in the behavior of axially bound amine groups is attributed to the free rotation of the axially bound N(CH3)iH3,i ligands that is required for the oxidation to proceed. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source]

Efficient Synthesis of Protein-Drug Conjugates Using a Functionalizable Recombinant Elastin-Mimetic Polypeptide

MACROMOLECULAR BIOSCIENCE, Issue 11 2006
Doris Kaufmann
Abstract Summary: This report describes the efficient conjugation of doxorubicin-glycine-phenylalanine-leucine-glycine (1a) and rhodamine-glycine-phenylalanine-leucine-glycine (1b) units to a monodisperse elastin-mimetic polypeptide (EMM)7 bearing eight primary amine groups for chemical attachment. The synthetic approach is based on the solid-phase synthesis of 1a and 1b followed by chemical conjugation to the elastin-mimetic polypeptide in the presence of HOBt/PyBob as activating agents to form the polypeptide conjugates 2a and 2b. Conjugation efficiency was 61.2% (4.9 doxorubicin units per polypeptide chain) for 2a and 53.7% (4.3 rhodamine units per polypeptide chain) for 2b, demonstrating the feasibility of using these tailor-made, recombinant polypeptides as potential drug carriers for cancer therapy. Schematic structure of the elastin-mimetic polypeptide (EMM)7. [source]

Pulsed-Plasma Polymeric Allylamine Thin Films

PLASMA PROCESSES AND POLYMERS, Issue 8 2009
Zhilu Yang
Abstract High surface functional groups concentration, excellent dynamical stability and mechanical properties are ideal for biomedical plasma polymers. Herein, we report a simple and effective approach to fabricating such an ideal plasma polymeric allylamine film on 316L stainless steel (SS) by pulsed plasma polymerization. The experimental results show that the concentration of the primary amine groups (NH2/C) of the plasma polymeric allylamine film was 2.4,±,0.4%. The plasma polymeric allylamine film possesses not only high surface NH2 concentration, but also high cross-linking degree and close-knit network structure that could well resist hydrolysis, and dissolution in the aqueous solution. Furthermore, the plasma polymeric allylamine film was used as a stent coating that shows a good resistance to the deformation behaviour of compression and expansion of the stent. [source]

Organic ion exchangers as beads.

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 7-8 2006
Synthesis, applications, characterization
Abstract Two less explored strategies in the preparation of porous organic ion exchangers in bead form are presented in this paper: the preparation of macroporous strong base anion exchangers with N,N -diethyl-2-hydroxyethyl benzylammonium chloride units, a less explored chloromethylation reagent of the styrene-divinylbenzene copolymers being used, and the preparation of anion exchangers with primary amine groups by the aminolysis-hydrolysis reaction with 1,2-diaminoethane of the nitrile groups, contained in some porous copolymers of acrylonitrile-divinylbenzene, followed by the carboxymethylation of the primary amine groups to prepare chelating ion exchangers. The influence of porogen nature, monomers dilution and crosslinking degree on the properties of the ion exchangers was examined. Structural characterization, functionalization-morphology correlations, the ion exchange properties, and potential applications for the ion exchangers thus prepared have been discussed. Copyright © 2006 John Wiley & Sons, Ltd. [source]