Synthesis and characterization of bioreactive‐end‐group‐containing azoinitiators and their use for preparing end‐functionalized polyvinylpyrrolidone

Abstract

SYNOPSISNew azonitrile initiators carrying N-hydroxysuccinimide (ACPS) or biotin derivative (ACP-LC-B) moieties were synthesized from 4,4'-azobis(4-~yanopentanoic acid) (ACPA) with a yield of around 60%. Special care was taken in the assignment of the l3C-NMR resonances of the ACP-LC-B. The kinetic and thermal parameters associated with these initiators were determined by UV spectroscopy and differential scanning calorimetry.

Polypeptide–polymer bioconjugates

“…213,214 In order to circumvent the need for postpolymerization modifications, biotin can already be incorporated into the initiator that is used for the synthesis of the polymer. This approach has been carried out for azonitrile initiators, 215 cyanoxyl-mediated polymerization, 216,217 ATRP [218][219][220] and RAFT. 221,222 Because the acid group is not involved in the complexation with the protein, these modifications do not change the binding characteristics much.…”

Chemically Induced Dynamic Electron Spin Polarization-Detected Energy Transfer. Substrate Size Effects and Solvent Dependence

“…The rate of photochemical decomposition of 1 in the presence of various sensitizers can be measured using UV/vis spectroscopy. This method has been used to study many polymeric free radical initiator systems. − Because the intensity of the absorption band of the azo moiety at 346 nm is directly proportional to the concentration of the nondecomposed azo compounds, the rate constant for decomposition can be determined with the following equation: 17 where A 0 and A t represent the absorbance of the azo moiety at times 0 and t , respectively, and k d is the rate constant of decomposition. Figure shows the graph of ln( A 0 / A t ) for three sensitizers, naphthalene, 1-methylnaphthalene, and 1-chloronaphthalene.…”

Thermal decomposition of some azo initiators. Influence of chemical structure

“…However, for occasional experiments, the elaborate equipment required turns out to be a drawback 31) . The UV spectrophotometry method is also widely used [32][33][34] . The absorption of the azo band at about 350 nm, is directly proportional to the concentration of undissociated initiator.…”