Frustrated Lewis Pair Polymers as Responsive Self-Healing Gels.

Steric bulk prevents the formation of strong bonds between Lewis acids and bases in frustrated Lewis pairs (FLPs), where latent reactivity makes these reagents transformative in small molecule activations and metal-free catalysis. However, their use as a platform for developing materials chemistry is unexplored. Here we report a fully macromolecular FLP, built from linear copolymers that containing either a sterically encumbered Lewis base or Lewis acid as a pendant functional group. The target functional copolymers were prepared by a controlled radical copolymerization of styrene with designer boron or phosphorus containing monomers. Mixtures of the B- and P-functionalized polystyrenes do not react, with the steric bulk of the functional monomers preventing the favorable Lewis acid base interaction. Addition of a small molecule (diethyl azodicarboxylate) promotes rapid network formation, cross-linking the reactive polymer chains. The resulting gel is dynamic, can self-heal, is heat responsive, and can be reshaped by postgelation processing.

[1]  Arne Thomas,et al.  Room-Temperature Activation of Hydrogen by Semi-immobilized Frustrated Lewis Pairs in Microporous Polymer Networks. , 2017, Journal of the American Chemical Society.

[2]  Xiaochu Ding,et al.  Weak Bond-Based Injectable and Stimuli Responsive Hydrogels for Biomedical Applications. , 2017, Journal of materials chemistry. B.

[3]  D. Stephan.  The broadening reach of frustrated Lewis pair chemistry , 2016, Science.

[4]  D. Stephan.  Frustrated Lewis pairs: from concept to catalysis. , 2015, Accounts of chemical research.

[5]  T. Nishida,et al.  2,6-Diphospha-s-indacene-1,3,5,7(2 H,6 H)-tetraone: a phosphorus analogue of aromatic diimides with the minimal core exhibiting high electron-accepting ability. , 2014, Chemistry.

[6]  I. Sivaev,et al.  Lewis acidity of boron compounds , 2014 .

[7]  F. Jäkle,et al.  Electron-deficient triarylborane block copolymers: synthesis by controlled free radical polymerization and application in the detection of fluoride ions. , 2013, Journal of the American Chemical Society.

[8]  C. Bowman,et al.  Covalent adaptable networks: smart, reconfigurable and responsive network systems. , 2013, Chemical Society reviews.

[9]  E. Carmona,et al.  Cyclometalated iridium complexes of bis(aryl) phosphine ligands: catalytic C-H/C-D exchanges and C-C coupling reactions. , 2013, Inorganic chemistry.

[10]  C. Bowman,et al.  Covalent adaptable networks: reversible bond structures incorporated in polymer networks. , 2012, Angewandte Chemie.

[11]  Justin R. Kumpfer,et al.  Optically healable supramolecular polymers , 2011, Nature.

[12]  Brian J. Adzima,et al.  Covalent Adaptable Networks (CANs): A Unique Paradigm in Crosslinked Polymers. , 2010, Macromolecules.

[13]  Douglas W Stephan,et al.  Frustrated Lewis pairs: metal-free hydrogen activation and more. , 2010, Angewandte Chemie.

[14]  Tibor András Rokob,et al.  Rationalizing the reactivity of frustrated Lewis pairs: thermodynamics of H(2) activation and the role of acid-base properties. , 2009, Journal of the American Chemical Society.

[15]  Brian J. Adzima,et al.  Rheological and chemical analysis of reverse gelation in a covalently crosslinked Diels-Alder polymer network. , 2008, Macromolecules.

[16]  D. Leznoff,et al.  The use of aurophilic and other metal-metal interactions as crystal engineering design elements to increase structural dimensionality. , 2008, Chemical Society reviews.

[17]  D. Bourissou,et al.  Tracking reactive intermediates in phosphine-promoted reactions with ambiphilic phosphino-boranes. , 2008, Chemical communications.

[18]  C. L. Drian,et al.  Development of Efficient and Reusable Diarylphosphinopolystyrene-Supported Palladium Catalysts for C ? C Bond Forming Cross-Coupling Reactions , 2007 .

[19]  Gregory C. Welch,et al.  Facile heterolytic cleavage of dihydrogen by phosphines and boranes. , 2007, Journal of the American Chemical Society.

[20]  Jason D. Masuda,et al.  Reversible, Metal-Free Hydrogen Activation , 2006, Science.

[21]  S. Kitagawa,et al.  Dynamic porous properties of coordination polymers inspired by hydrogen bonds. , 2005, Chemical Society reviews.

[22]  C. Janiak.  Engineering coordination polymers towards applications , 2003 .

[23]  Yang Qin,et al.  Well-defined boron-containing polymeric lewis acids. , 2002, Journal of the American Chemical Society.

[24]  J. Chiefari,et al.  Living free-radical polymerization by reversible addition - Fragmentation chain transfer: The RAFT process , 1998 .

[25]  M. Beckett,et al.  A convenient n.m.r. method for the measurement of Lewis acidity at boron centres: correlation of reaction rates of Lewis acid initiated epoxide polymerizations with Lewis acidity , 1996 .

[26]  ボミ・ピー・パテル.  Diaryl (pyridinio and isoquinolinio) boron fungicides , 1994 .

[27]  V. Gutmann.  Solvent effects on the reactivities of organometallic compounds , 1976 .

[28]  V. Gutmann,et al.  The acceptor number — A quantitative empirical parameter for the electrophilic properties of solvents , 1975 .

[29]  W. Hayes,et al.  Donor–Acceptor π–π Stacking Interactions: From Small Molecule Complexes to Healable Supramolecular Polymer Networks , 2015 .

[30]  M. Anthamatten.  Hydrogen Bonding in Supramolecular Polymer Networks: Glasses, Melts, and Elastomers , 2015 .

[31]  G. Erker,et al.  Intramolecular frustrated lewis pairs: formation and chemical features. , 2013, Topics in current chemistry.

[32]  N. Peppas,et al.  Structure and Interactions in Covalently and Ionically Crosslinked Chitosan Hydrogels for Biomedical Applications , 2003 .