Diaminopyridine functionalized

Triazine or diaminopyridine bithiophene copolymerization triazine or diaminopyridine functionalized biothiophene with bithiophene integrated current from cyclic voltammogram 21... 

Fig. 22 Schematic illustration of the immobilization of diaminopyridin-functionalized Au nanoparticles onto thymine-modified self-assembled 8-sheet nanofiber through comple-mental base-pairing in apolar solvent. (Adapted from [75])...

Random polynorbomene-based terpolymer 5 (Fig. 5.8) functionalized with SCS palladated pincer complexes, dibenzo[24]crown-8 (DB24C8) rings, and 2,6-diaminopyridine units was synthesized by ROMP (South et al. 2006). The palladium complex serves as the anchoring unit for metal coordination, 2,6-diaminopyridine as the DAD hydrogen bonding moiety, and DB24C8 as the precursor for pseudorotaxane formation, which has been smdied extensively by Stoddart and his group... 

Figure 5.16 2,6-Diaminopyridine side chain functionalized polystyrene cross-linked via bis-thymine cross-linking agents.

Figure 5.8 Three recognition motifs based on (a) hydrogen bonding interactions between 2,6-diaminopyridine and thymine, (b) metal coordination of sulfur-carbon-sulfur (SCS) Pd pincer with pyridine, (c) pseudorotaxane formation between dibenzo[24]crown-8 (DB24C8) and dibenzylammonium ions, and (d) fully functionalized terpolymer 5.

The aminopyridines (4-aminopyridine 3,4-diaminopyri-dine) accelerate spontaneous exocytosis at central and peripheral synapses. There is also an increase in the number of transmitter quanta released by a nerve action potential. This is probably the result of increased Ca++ inflow at the terminals due to a reduction of K+ conductance and prolongation of the nerve action potential. Muscle strength is increased in patients with the Lambert-Eaton myasthenic syndrome and in others poisoned with botuUnum E toxin (discussed later). Improvement in uncontrolled spasms, muscle tone, and pulmonary function is noted in patients with multiple sclerosis or long-standing spinal cord damage. Side effects that limit clinical utility include convulsions, restlessness, insomnia, and elevated blood pressure. Of the two agents, 3,4-diaminopyridine is the more potent and crosses the blood-brain barrier less readily. 

In 2004, Week and co-workers demonstrated that both mono- and multifunctional self-assembly could be employed simultaneously independently and reversibly on the same side-chain functionalized polymer [96]. A random terpolymer of poly(norbornene) was synthesized consisting of diaminopyridine (DAP) hydrogen-bonding receptors and a palladium-functionalized SCS-type pincer ligand for metal coordination-based self-assembly (Fig. 7.18). 

Two of the reactions summarized in Tables VI and VII require some comment. The reaction of 3-hydroxypyridine with an excess of sodamide at 210° results in the elimination of the hydroxyl group and the formation of 2,6-diaminopyridine. Plazek288 attributed this to the reduction of the phenolic function by nascent hydrogen. More recently, however, this reaction has been interpreted as providing evidence for the intermediacy of a 2,3-pyridyne species in this reaction271 ... 

N,N -dimethylacetamide was prepared from pyromellitic dianhydride and the functional diamines, 3,S-diamino-l,2,4-triazole 2,5-diaminobenzoic acid 2,5-diaminobenzene sulfonic acid or 2,6-diaminopyridine. Each pre-polymer solution was then dispersed as droplets in paraffin oil containing poly(maleic anhydride-co-octadec-l-eneXl l) as a suspension stabilizer, and imidization induced at 60C by addition of a mixture of acetic anhydride and pyridine (Figure 1). 

The reaction can be extended to other dinucleophiles like aliphatic diamines, diaminopyridines, diaminopyrimidines <85S867>, 2-aminothiophenol, or 2-aminophenol <87S368>. Isocyanatothiazoles are highly reactive compounds which upon treatment with nucleophiles afford the corresponding adducts <91JHC1003>. These adducts can be elaborated to further functionalized compounds <91JHC1013>. 

The dc electrical conductivity of a number of N-(2-pyridyl)benzamide and N, N -dibenzoyl-2,6-diaminopyridine metal complexes, as a function of temperature (to 388 K) and radiation, was studied by Abou Sekkina et al. (61). Linear log versus l/T plots were obtained for all the Cu(II) and Ni(II) complexes, from which the activation energy, Ea, and other parameters could be calculated, using the expression... 

The most commonly used ADA modules contain the pyrimidine-2,4-dione nucleus. Not surprisingly, N-alkylation of thymine or uracil with an alkyl halide provides a simple, one-step method of functionalizing this module. Other ADA units include simple imides (e.g., 10), heterocycle 13, which was used by Kelly in a bisubstrate reaction template [17], and the anthyridinone or anthyridan units in 15 and 18, respectively. The latter modules are synthesized by double Friedlander condensation of 2,6-diaminopyridine-3,5-dicarboxal-... 

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