title: Engineering Functionalization in a Supramolecular Polymer: Hierarchical Self-Organization of Triply Orthogonal Non-covalent Interactions on a Supramolecular Coordination Complex Platform.
abstract: Here we present a method for the construction of functionalizable supramolecular polymers by controlling three orthogonal interactions within a single system: (i) coordination-driven self-assembly; (ii) H-bonding; and (iii) host-guest interactions between crown ether and dialkylammonium substrates. Three unique molecules constitute the supramolecular construct, including a 2-ureido-4-pyrimidinone (UPy)-functionalized rigid dipyridyl donor and a complementary organoplatinum(II) acceptor decorated with a crown ether moiety that provide the basis for self-assembly and polymerization. The final host-guest interaction is demonstrated by using one of two dialkylammonium molecules containing fluorophores that bind to the benzo-21-crown-7 (B21C7) groups of the acceptors, providing a spectroscopic handle to evaluate the functionalization. An initial coordination-driven self-assembly yields hexagonal metallacycles with alternating UPy and B21C7 groups at their vertices. The assembly does not interfere with H-bonding between the UPy groups, which link the discrete metallacycles into a supramolecular network, leaving the B21C7 groups free for functionalization via host-guest chemistry. The resultant network results in a cavity-cored metallogel at high concentrations or upon solvent swelling. The light-emitting properties of the dialkylammonium substrates were transferred to the network upon host-guest binding. This method is compatible with any dialkylammonium substrate that does not disrupt coordination nor H-bonding, and thus, the unification of these three orthogonal interactions represents a simple yet highly efficient strategy to obtain supramolecular polymeric materials with desirable functionality.
authors.affiliation: Department of Chemistry, University of Utah , 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112, United States.
authors.forename: Zhixuan
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Department of Chemistry, University of Utah , 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112, United States.
authors.forename: Xuzhou
authors.initials: X
authors.lastname: Yan
authors.affiliation: Department of Chemistry, University at Buffalo , 359 Natural Sciences Complex, Buffalo, New York 14260, United States.
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Cook
authors.affiliation: Department of Chemistry, University of Utah , 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112, United States.
authors.forename: Manik Lal
authors.initials: ML
authors.lastname: Saha
authors.affiliation: Department of Chemistry, University of Utah , 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112, United States.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Stang