Chromo- and fluorophoric water-soluble polymers and silica particles by nucleophilic substitution reaction of poly(vinyl amine)

Abstract

SummaryNovel chromophoric and fluorescent carbonitrile-functionalized poly(vinyl amine) (PVAm) and PVAm/silica particles were synthesized by means of nucleophilic aromatic substitution of 8-oxo-8H-acenaphtho[1,2-b]pyrrol-9-carbonitrile (1) with PVAm in water. The water solubility of 1 has been mediated by 2,6-O-β-dimethylcyclodextrin or by pre-adsorption onto silica particles. Furthermore, 1 was converted with isopropylamine into the model compound 1-M. All new compounds were characterized by NMR, FTIR, UV–vis and fluorescence spectroscopy. The solvent-dependent UV–vis absorption and fluorescence emission band positions of the model compound and the carbonitrile-functionalized PVAm were studied and interpreted using the empirical Kamlet–Taft solvent parameters π * (dipolarity/polarizability), α (hydrogen-bond donating capacity) and β (hydrogen-accepting ability) in terms of the linear solvation energy relationship (LSER). The solvent-independent regression coefficients a, b and s were determined using multiple linear correlation analysis. It is shown, that the chains of the polymer have a significant influence on the solvatochromic behavior of 1-P. The structure of the carbonitrile 1-Si bound to polymer-modified silica particles was studied by means of X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET) measurements. Fluorescent silica particles were obtained as shown by fluorescence spectroscopy with a diffuse reflectance technique.

Differences in Catalytic Activity of Poly(vinylamine) Introduced on Surface of Mesoporous SBA-15 by Grafting from and Grafting onto Methods in Knoevenagel Condensation

“…The spectra collected for SBA-15_VTS_PVAm_2.5 and SBA-15_GPTMS_PVAm_2.5 are shown in Figure B. After the modification, the appearance of new absorption bands characteristic of PVAm is observed in the ranges of 2800–3400 and 1300–1700 cm –1 . , The peaks at 3290 and 3350 cm –1 are assigned to the asymmetric and symmetric N–H stretching modes of −NH 2 groups, whereas the band at 1595 cm –1 appears because of the −NH 2 bending mode. Additionally, the stretching (2820–2980 cm –1 ) and deforming (1350–1460 cm –1 ) vibrations of C–H in the polymer backbone are noticeable.…”

A design approach to eliminate the toxic effect of insecticides to ensure human safety

“…Thioxanthone catechol-O,O-diacetic acid (TX-Ct) was prepared according to a reported method. 19 AVM (97.0% purity) was purchased from Aladdin Biochemical Technology Co. Ltd (Shanghai, China). AVM emulsifiable concentrate (AVM-EC) (5% mass ratio) was obtained from Hubei Xingbai Agricultural Technology Co. Ltd. Methanol was purchased from Honeywell International Inc. Epichlorohydrin, sodium hydroxide (96.0%), urea (99.0%), and ethanol (98.0%) were purchased from Cologne Chemicals Co. Ltd. Distilled water was prepared using a Milli-Q ultrapure water apparatus.…”

Discovery of a novel family of polycyclic aromatic molecules with unique reactivity and members valuable for fluorescent sensing and medicinal chemistry

“…Different from our strategy to synthesize a siloxane-substituted fluorophore for direct modification of silica nanoparticles, Spange et al 14 established a novel and convenient two-step approach toward fluorophore-functionalized silica particles. As demonstrated in Scheme 10, they used silica as a 'solubilizer' which could absorb the water insoluble precursor 1 and water soluble poly(vinyl amine) (PVAm) and simultaneously provided them a large specific surface area to undergo the S N Ar H reaction.…”