Poly functional amines

Silane crosslinking Isocyanates Poly-functional amines High-energy radiation... 

Thermosetting acrylic copolymers containing epoxy groups are usually cross-linked by poly functional amines, e.g. ... 

It has been demonstrated that dendrimers can be used also as fluorescent sensors for metal ions. Poly(propylene amine) dendrimers functionalized with dansyl units at the periphery like 34 can coordinate metal ions by the aliphatic amine units contained in the interior of the dendrimer [80]. The advantage of a dendrimer for this kind of application is related to the fact that a single analyte can interact with a great number of fluorescent units, which results in signal amplification. For example, when a Co ion enters dendrimer 34, the fluorescence of all the 32 dansyl units is quenched with a 32-fold increase in sensitivity with respect to a normal dansyl sensor. This concept is illustrated in Fig. 3. 

A first generation poly(amido amine) dendrimer has been functionalized with three calyx[4]arenes, each carrying a pyrene fluorophore (4) [30]. In acetonitrile solution the emission spectrum shows both the monomer and the excimer emission band, typical of the pyrene chromophore. Upon addition of Al3+ as perchlorate salt, a decrease in the excimer emission and a consequent revival of the monomer emission is observed. This can be interpreted as a change in the dendrimer structure and flexibility upon metal ion complexation that inhibits close proximity of pyrenyl units, thus decreasing the excimer formation probability. 1H NMR studies of dendrimer 4 revealed marked differences upon Al3+ addition only in the chemical shifts of the CH2 protons linked to the central amine group, demonstrating that the metal ion is coordinated by the dendrimer core. MALDI-TOF experiments gave evidence of a 1 1 complex. Similar results have been obtained for In3+, while other cations such as Ag+, Cd2+, and Zn2+ do not affect the luminescence properties of... 

Figure 13.10 Synthesis of mannose-/glucose-functionalized dendrimers. For dendrimer loading, x + y = 50% loading was used because optimal activity for glycodendrimers with concanavalin A was previously determined to occur at 50% functionalization. Remaining amines from the poly(amido amine) (PAMAM) substrate were capped as alcohols.

We have prepared a wide series of Mo(VI)-grafted poly(amido amine) resins based on aminoacids with varying distances between the aminic and carboxylic groups. We have found that the catalytic activity of these resins is strongly dependent on that distance, maximum activity within this series being obtained when the resin supposedly co-ordinates to a Mo(VI)02 core in a quadridentate manner throught the use of two suitably located adjacent carboxylic functions. 

Figure 15.21 Synthesis of geometrically varied mono-functionalized poly (amino)-guanidine building blocks ( Libraires trom libraries ) tor the synthesis of geometrically varied lipo-poly-guanidinium-amines.

Byk, G., Soto, J., Mattler, C., Frederic, M. and Scherman, D. (1998b) Novel non-viral vectors for gene delivery Synthesis of a second generation library of mono-functionalized poly-(guanidinium)amines. Biotech. Bioeng., 61, 81-87. 

A series of chiral phosphine-functionalized poly(propyleneimine) (PPI) and poly(amido)amine (PAMAM) dendrimers was synthesized by reaction... 

The different situations of the block copolyampholyte as a function of pH are depicted in Scheme. 1. The same order of deprotonation was observed in copolymers of poly(methacrylic acid) and poly(2-(diethylamino)ethyl methacrylate) [70, 71, 72, 75-77]. In copolymers of poly(methacrylic acid) [78] and poly(2/4-vinylpyridine), on the other hand, deprotonation of the pyridine hydrochloride takes place prior to deprotonation of the carboxyl [79-83] because in comparison to carboxylic functionalities amine hydrochlorides are the weaker acids and vinylpyridinium hydrochlorides the stronger ones. Thus, in the latter systems an isoelectric point (iep) is not observable, while in the first case polyzwitterions are formed which possess the highest amount of charges at that pH resulting in a polyelectrolyte complex (PEC). In the second case polymers with a minimal net charge built the PEC which is stabilized by hydrophobic interactions often accompanied by hydrogen bonding [79, 84-88]. 

Poly(amido-amine)s are a class of polymers characterized by the presence of amido and amino groups regularly arranged along the macromolecular chain. Additional functional groups may be introduced as side substituents. 

Poly(amido amine)s carrying additional functions as side substituents can be easily obtained, starting with the appropriate monomers 38,44>. In fact, hydroxyl groups, tertiary amino groups, allyl groups, etc., if present in the monomers, do not interfere with the polymerization process. 

Fig. 1. (a) A chemical structure of a 2.5th generation carboxylic acid-terminated poly(amido amine) (PAMAM) dendrimer. (b) Transmission surface enhanced infrared absorption spectra (SEIRAS) of dendrimer adlayers prepared at 30 min adsorption from aqueous solutions (0.01 wt.%) of a dendrimer at different pHs. Numerical values are pHs of the solutions, (c) Adsorption-desorption profiles as a function of time at different pHs and adlayer thicknesses at adsorption and desorption equilibrium as a function of pH for aqueous solutions (0.1 wt.%) of the dendrimer. The symbols, j and J, in the top figure denote start of adsorption and desorption, respectively. In the bottom figure, filled circle and opened square denote adlayer thicknesses at adsorption and desorption equilibrium, respectively. The dark tie denotes the calculated dendrimer size width. A solid curve is drawn to be visual, (d) Schematic illustration of dendrimers adsorbed at different pHs. Reprinted with permission from Ref. [69], 2006, American Scientific Publishers. 

Ultrathin hydrogels are prepared from poly(vinyl amine-co-N-vinylformamide) and poly(acrylic acid) using EDC. Such soluble functionalized nanotube/PVA composites are used as an electrode for glucose sensing. ... 

The replacement reaetion by poly functional nitrogen-containing derivatives, in particular, makes it possible to introduce multiple RCH2 groups into the same molecule. Thus, the reaction of indole Mannich bases with ammonia y ields bis- and tris-(3-indolyl) amines. Likewise, primary amines, hydrazine, and hydroxylamine can be bis-alkylated by several Mannich bases. 

Most of the poly functional substrates belonging to this group of compounds have two (or more) active hydrogen atoms located on different positions of the molecule. Thus, in the case of symmetrical substrate with two identical reactive XH groups 109, the Mannich bases 110-115 (Rg. 42) arc obtained by reaction of the. substrate with formaldehyde and amine in the molar ratio 123. 

Dendrimers of the poly(propylene amine) family can be easily functionalized in the periphery with luminescent imits such as dansyl (31). The resulting dendrimers nD, where the generation number n goes from 1 to 5, comprise 2 " dansyl fimctions in the periphery and 2 tertiary amine units in the interior. 

Fig. 9. Formula of a dendrimer constituted by a poly(propylene amine) structure functionalized with 32 dansyl units at the periphery, capable of coordinating Co ions, and the corresponding scheme (Fig. 2d).

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