Installation of Zwitterionic α‐Amino Phosphonic Acid Moieties on Surfaces via a Kabachnik‐Fields Post‐Polymerization Modification

Abstract

An organic-inorganic hybrid polymer, composed of poly(methylsilsesquioxane) (PMSSQ) and poly(4-vinyl benzaldehyde) (PStCHO), is prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization of 4-vinyl benzaldehyde (StCHO) using a macro-chain transfer agent (CTA) based on PMSSQ. The obtained PMSSQ-PStCHO is spin-coated on substrates such as silicon wafers or copper plates to afford aldehyde-functionalized surfaces. Successful Kabachnik-Fields post-polymerization modifi cation (KF-PMR) of the aldehyde-functionalized surfaces is conducted with amines and dialkyl phosphonates, and characterized by surface analysis techniques including IR, energy-dispersive X-ray (EDX), and X-ray photoelectron spectroscopy (XPS) measurements, documenting the installation of α-amino phosphonates onto surfaces with practically quantitative conversion of aldehydes. In addition, the generated α-amino phosphonates are successfully deprotected to afford the corresponding α-amino phosphonic acids on surfaces, which make this route a reliable tool-enabling surface functionalization with α-amino phosphonic acids.surfaces. To expand the scope of functional materials featuring designed surface characteristics, a number of highly reactive and selective reactions, so-called "click reactions", have been employed. This includes Cu(I)-catalyzed and metal-free 1,3-dipolar cycloaddition (CuCAAC) reaction of organo-azides and alkynes, [ 1,2 ] thiol-ene, thiol-maleimide, [ 3 ] nucleophile-isocyanate, [ 4 ] and activated ester-amine reactions, which all realize a facile functionalization of substrate surfaces. [5][6][7][8] In spite of the fact that these click reactions have been employed in surface modifi cation chemistry, the intrinsic drawbacks of these conventional "click reactions" are: 1) only one functionality per one reaction can be achieved and 2) no functionality owing to linkages that are generated via reactions. In order to target material surfaces featuring more sophisticated functionalities, chemists need to propose a synthetic strategy realizing installation two or more functional molecules per single reactive site accompanied with a generation of an attracting linkage.

Investigation of Antifouling Properties of Surfaces Featuring Zwitterionic α‐Aminophosphonic Acid Moieties

“…For this, we conducted a surface Kabachnik–Fields reaction ( sur ‐KFR) to install polymeric α‐aminophosphonates starting from a poly(methylsilsesquioxane)‐poly(4‐vinyl‐benzaldehyde) (PMSSQ–PStCHO) coating. Next, the deprotection of polymeric α‐aminophosphonates immobilized on a silicon substrate was conducted …”

“…4‐Vinyl benzaldehyde (StCHO) and poly(4‐vinyl benzaldehyde) (PStCHO) were synthesized according to previous reports . PMSSQ Macro‐CTA and PMSSQ–PStCHO were synthesized as described in ref …”

Antioxidant Polymers via the Kabachnik‐Fields Reaction to Control Cellular Oxidative Stress

“…[ 37–40 ] However, the KF reaction has been used only recently in polymer chemistry. [ 26,28,29,41–45 ] Some new polymers have been prepared via the KF reaction and used as flame‐resistant and antibacterial materials. [ 43–45 ] However, the preparation of antioxidant polymers via the KF reaction has not been reported.…”

“…[ 26,28,29,41–45 ] Some new polymers have been prepared via the KF reaction and used as flame‐resistant and antibacterial materials. [ 43–45 ] However, the preparation of antioxidant polymers via the KF reaction has not been reported. In this research, water‐soluble KF copolymers have been prepared through a one‐pot KF‐FRP method using aliphatic and aromatic aldehydes for the KF reaction.…”

Versatile side chain modification via isocyanide-based multicomponent reactions: tuning the LCST of poly(2-oxazoline)s

“…[23][24][25][26] Especially the latter Ugi-4CR found its way into the field of biomedical chemistry as PEGylation method of proteins under simultaneous introduction of fluorescent agents or other functional groups. 27,28 Nonetheless, many other multicomponent reactions were introduced to polymer science as well, such as the Kabachnik-Fields, [29][30][31] Biginelli, 32,33 Asinger, 34 Hantzsch, 35 or the Cu-catalyzed reaction of alkynes, sulfonyl azides and amines. 36 In most of these reactions, the MCRs were used for the polymer synthesis by a monomeric or polymeric approach, whereas post-polymerization modifications with MCRs were only rarely applied.…”