A comparative study of diaryl carbene insertion reactions at polymer surfaces

Abstract

A detailed investigation of the reactions of diaryldiazo compounds for the surface modification of several polymers has been conducted. This has revealed that the rate of reaction of diaryldiazo compounds is influenced by their substituents, that the reaction is exothermic, and that the polymer itself exerts an influence on the surface modification. The results are consistent with the formation and insertion of a carbene intermediate at the polymer surface. It was further shown that such surface modified polymers, characterized using surface sensitive techniques, display macroscopic behavior consistent with the presence of the newly introduced surface chemical functionality, characterized using a combination of surface sensitive and bulk analytical techniques. This approach is complementary to directed energy deposition approaches, offers an alternative route to functional polymers, and provide a direct link between surface chemistry and observable macroscopic properties.

Ag NP-Loaded Cotton Fiber Materials: Preparation, Surface Deposition, and Antibacterial Activity with Different Chemical Structures

“…The diazomethane 5 is suitable for conversion into carbene 6 by heating, which could react with many materials and introduce various functional groups onto the substrate efficiently. 35,36 As shown in Scheme 2, cotton fiber 7 (cotton-OH) was mixed with bis(diaryldiazomethane) 5 evenly before being heated to 120 °C, from which carbenes were generated. The insertion of carbene with O−H bonds on the cotton gave the modified cotton fiber 8 (cotton-NH 2 ), now with amino groups on the surface.…”

“…As shown in Scheme , amino-substituted bis­(diaryldiazomethane) 5 was synthesized from 4-phenoxyaniline through Friedel–Crafts acylation with isophthaloyl chloride, reduction with hydrazine monohydrate, and oxidation with manganese dioxide. The diazomethane 5 is suitable for conversion into carbene 6 by heating, which could react with many materials and introduce various functional groups onto the substrate efficiently. , …”

Carbene modification and reversible crosslinking of silver nanoparticles for controlled antibacterial activity

“…The hydrazone was then oxidized with manganese dioxide to obtain furyl diazomethane 3. 4-Chloro-4′-hydroxybenzophenone is chosen as substrate because the phenolic hydroxyl group provides convenient conditions to permit introduction of the furyl side chain, but unfortunately also activates the diazomethane towards carbene formation; the electron withdrawing chloro group on the other aromatic ring helps to provide some additional stability to the diazomethane 26 . This protocol is designed to introduce furyl groups into the diazomethane by mild reaction conditions.…”

Surface modified materials for active capture of enzymes

“…8 We have earlier shown that surface modification of a variety of substrates, i.e. polymeric beads and powder using diaryldiazomethane derivatives leads to surface loading values of 10 13 -10 15 molecules per cm 2 , 9 and of 10 11 -10 13 molecules per cm 2 via using bisdiazo derivatives for filter paper and Hybond TM membrane. 10 Of interest to us was whether this process might be successfully applied to macromolecule (enzyme) capture, and whether this loading level would give measurable and useful activity sufficient for bioengineering applications.…”