Supramacromolecular self‐assembly: Chain extension, star and block polymers via pseudorotaxane formation from well‐defined end‐functionalized polymers

Abstract

Dibenzo‐24‐crown‐8‐terminated polystyrene (5) was chain extended to “dimeric” 8 by pseudorotaxane formation with a ditopic guest, α,ω‐bis[p‐(N‐benzylammoniomethyl)phenoxy]heptane bis(hexafluorophosphate) (7). The three‐armed star polymer 11 was similarly formed by complexation of the dibenzo‐24‐crown‐8‐terminated polystyrene (5) with a tritopic secondary ammonium salt, 1,3,5‐tris[p‐(benzylammoniomethyl)phenyl]benzene tris(hexafluorophosphate) (10). Another three‐armed star polymer 13 was self‐assembled from dibenzo‐24‐crown‐8‐terminated polystyrene (5) and a tetratopic paraquat compound, 1,2,4,5‐tetrakis{p‐N‐[(N′‐methyl‐4,4′‐bipyridinium)methylphenyl]}benzene octakis(hexafluorophosphate) (12). The above chain extension and star polymer formation processes seemed to be cooperative; that is, the second and third complexation steps proceed with stepwise higher efficiencies than statistically expected. Dibenzo‐24‐crown‐8‐terminated polystyrene (5) was chain extended with secondary ammonium terminated polystyrene 14, forming 16, and also self‐assembled with a secondary ammonium ion terminated polyisoprene 15 to form supramolecular block copolymer 17. These processes were examined by NMR, mass spectrometry and viscometery. Thus, although binding in these systems is not particularly strong (association constants <104 M−1), these examples provide proof‐of‐principle that pseudorotaxane formation is a viable concept for chain extension and self‐assembly of novel types of block copolymers and star polymers. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3518–3543, 2009

Terminology and nomenclature for macromolecular rotaxanes and pseudorotaxanes (IUPAC Recommendations 2012)

“…[3][4][5][6][7][8][9][10][11]). Unlike the generic names introduced in Table 1, the names presented in this section are complete names including the names of end-groups of the macromolecular components, and they demonstrate the applicability of the nomenclature rules given in this document for highly complex macromolecular rotaxane assemblies.…”

“…Materials composed of these assemblies are known as "rotaxane polymers" and "pseudo rotaxane polymers" or, shortly but ambiguously (see further, MRO-1.9 and MRO-1.18), "poly rotaxanes" and "polypseudorotaxanes" [2][3][4][5][6][7]. These polymeric counterparts of rotaxanes and pseudorotaxanes have been reviewed, particularly in 1994 [3], 1999 [4], 2001 [5], 2005 [6], 2007 [7], 2009 [8][9][10], and 2010 [11].…”

“…α-group: 4-[ (6,7,9,10,12,13,20,21,23,24,26,27-dodecahydro dibenzo[b,n] [1,4,7,10,13,16,19,22] octaoxacyclotetracosin-2-yl)carbamoyl]benzoyl ω-group: (6,7,9,10,12,13,20,21, 23,24,26,27-dodecahydrodibenzo[b,n] [1,4,7,10,13,16,19,22] octaoxacyclotetracosin-2-yl)amino…”

Phase Behavior of Complementary Multiply Hydrogen Bonded End-Functional Polymer Blends

“…19 The nature of the interaction varies widely and most commonly consists of either metal-ligand, 20,21 ionic, 22,23 or hydrogen bonding. 24,25 Incorporation of these into various macromolecular architectures such as diblock, [26][27][28][29][30][31][32][33][34][35] triblock, [36][37][38] multiblock, [39][40][41] star 42 and graft copolymers, [43][44][45] blends, 35,46 and gels 47,48 has resulted in remarkably simple thermal control over the polymer structure and related properties.…”

Crown Ether‐Based Polymeric Rotaxanes

“…Recently, a chain extension was reported by Gibson et al which displayed cooperativity [32]. The chain extension system employed a DB24C8-terminated polystyrene 56 with the guest 57 to bring about the formation of a pseudorotaxane.…”