2‐Nitro‐1,4‐diaminobenzene‐Functionalized Poly(vinyl amine)s as Water‐Soluble UV‐Vis‐Sensitive pH Sensors

Abstract

Summary: Nucleophilic aromatic substitution of 2,6‐O‐dimethyl‐β‐cyclodextrin (β‐DMCD)‐complexed 4‐fluoro‐3‐nitroaniline derivatives with poly(vinyl amine) (PVAm) in water results in 2‐nitro‐1,4‐benzenediamine‐functionalized water‐soluble PVAms in one step. The 2‐nitro‐1,4‐benzenediamine moiety linked to the polymer is solvatochromic and undergoes protonation and deprotonation as function of pH as shown by UV‐Vis spectroscopy. The occurrence of an isosbestic point in the UV‐Vis spectrum is suitable to directly determine the pKa value using the Henderson‐Hasselbalch equation. The influence of the methyl group substitution of the polymer and the 2‐nitro‐1,4‐benzenediamine moiety on the pKa is discussed.Structure of the 4‐N,N‐dimethyl‐2‐nitro‐1,4‐benzenediamine‐functionalized PVAm and its solution in water at varying pH.imageStructure of the 4‐N,N‐dimethyl‐2‐nitro‐1,4‐benzenediamine‐functionalized PVAm and its solution in water at varying pH.

Synthesis of 2-{5-[4-((4-nitrophenyl)diazenyl)phenyl]-1,3,4-oxadiazol-2-ylthio}ethyl acrylate monomer and its application in a dual pH and temperature responsive soluble polymeric sensor

“…The design and development of 'smart' functional materials, which have a wide range of applications in various fields, such as DNA-sequence detection, [1,2] biotechnology, [3,4] drug delivery, [5][6][7] organic analysis, [8] particle transport, [9] thermometers, [10][11][12] bar codes [13] and optical imaging, [14][15][16] has gained a great deal of attention in the last years.…”

Influence of the Reaction Conditions and Molecular Structure on the Kinetic of the Nucleophilic Aromatic Substitution of Fluoro Compounds with Poly(vinyl amine) in Water

“…In addition, the non‐protonated primary amino groups of PVAm are suitable for many post‐derivatization reactions 1, 6b, 9, 10. Nucleophilic aromatic substitution (NAS) reaction of fluoroaromatics with PVAm offers a great synthetical potential to incorporate chromophores into the polymer backbone whereby a push‐pull substituted aromatic system is formed in only one step (Scheme ) 11…”

“…According to recent studies,11 it is of importance how substituents on the FC have an effect on the reactivity. Especially, the introduction of the ortho ‐nitro‐ para phenylenediamine moiety into PVAm chains is of special interest because of the indicator property 11c.…”

“…According to recent studies,11 it is of importance how substituents on the FC have an effect on the reactivity. Especially, the introduction of the ortho ‐nitro‐ para phenylenediamine moiety into PVAm chains is of special interest because of the indicator property 11c. Due to the amino substituent of 5 has an negative effect on the reactivity of aromatics for the NAS reaction, the reversible arresting of the primary amino group associated with an enhancement of the reactivity of FCs by chemical reaction has been studied in this work.…”

Bioactive Phenylenediamine Derivatives of Dehydroacetic Acid: Synthesis, Structural Characterization and Deuterium Isotope Effects

“…9 They were also reported to be used in polymerization reactions, as biosensor and as chelating ligands for coordination of transition metal cations. 10,11 In this paper we report on preparation of ortho (1)-, meta (2)-and para (3)-N,N´-phenylene-diylbis [3-(1-aminoethyl)-6-methyl-2H-pyran-2,4(3H)-diones] ( Figure 1) and their deuterated isotopomers (4)(5)(6) in order to study possible hydrogen bonding interactions and tautomeric keto-enol equilibria these compounds might undergo which in turn could affect their biological properties.…”