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Supramolecular polymers represent a family of polymeric materials that are held together with dynamic, noncovalent interactions. In contrast to conventional functional polymers that usually have high melt-viscosity due to their covalent nature and chain entanglement, supramolecular polymers combine excellent physical properties with low melt-viscosity, allowing for less energy-intensive processability and recyclability. Dynamic bonding with multiple binding sites, such as multiple hydrogen bonding or multiple ionic bonding, exhibits much stronger binding strength compared to the counterparts containing only a single binding site, thereby allowing for enhanced mechanical integrity to the polymers and facilitate self-assembly. This dissertation focuses on the design of novel supramolecular polymers building from the doubly-charged or quadruple hydrogen bonding (QHB) scaffolds utilizing chain-growth polymerization or step-growth polymerization, as well as elucidate the structure-property-morphology relationships of the polymers. A 2-step nucleophilic substitution reaction afforded a series of 1,4-diazabicyclo[2.2.2]octane (DABCO)-based styrenic monomers with two pairs of charged groups. An optimized 2-step reversible-addition-fragmentation chain-transfer (RAFT) polymerization synthesized ABA triblock thermoplastic elastomers (TPEs) with a low Tg poly (n-butyl acrylate) central block and a high Tg external charged blocks. Strong ionic interactions between doubly-charged units drove molecular self-assembly to form densely packed, hierarchical microstructures, which contributed to a robust, crosslinked physical network that allows the polymer to retain thermomechanical integrity until degradation. High-resolution single-crystal X-ray diffraction (SCXRD) coupled with powder X-ray diffraction (PXRD) further disclosed a detailed 3-D structural information of molecular arrangement and ion distribution within the charged phase through comparing DABCO-salt monomer single-crystal structure and the corresponding homopolymer XRD pattern. It was found that the physical properties of the DABCO-salt copolymers not only relied on their charge content and architectures but also dependent on their electrostatically-bonded counterions. The size and structure of the counterion determined the strength of dipole-dipole interaction, which significantly impact on thermal property, (thermo)mechanical performance, water affinity, and microstructure. A cytosine-functionalized monomer, cytosine acrylate (CyA), allowed the synthesis of acrylic ABA triblock TPEs with pendant nucleobase moieties in the external blocks and a low Tg central polymer matrix through RAFT polymerization. Post-functionalization of cytosine (Cyt) bidentate hydrogen bonding sites with alkyl isocyanate, allowed the formation of ureido-cytosine (UCyt) groups in the external block that were readily dimerized through QHB interactions. The UCyt units in the external block enhanced mechanical strength and induced stronger phase-separation of the block copolymers compared to the corresponding Cyt-containing TPE analogs. Facile conventional free-radical polymerization using CyA and subsequent post-functionalization enabled accessibility to random copolymers containing pendant UCyt QHB moieties in the soft polymer matrix. The synergy of the flexible polymer matrix and the dynamic character of QHB groups contributed to the ultra-high elasticity of the polymer and rapid self-healing properties. QHB interactions enabled efficient mechanical recovery upon deformation by facilitating elastic chain retraction to regenerate the original physical network. Finally, one-pot step-growth polymerization through chain extending a novel bis-Cyt monomer and a commercially available polyether diamine using a di-isocyanate extender afforded segmented polyurea series for extrusion additive manufacturing. The molecular design of the polyureas featured soft segments containing flexible polyether chain and a relatively weak urea hydrogen bonding sites in the soft segment and rigid UCyt hydrogen bonding groups in the hard segment. The reversible characteristics of QHB enabled low viscosity at the processing temperature while providing mechanical integrity after processing and reinforced bonding between the interlayers, which contributed to the remarkable strength, elasticity, toughness, and interlayer adhesion of the printed parts.

Cucurbit[n]urils (CB[n]) are hollow pumpkin-shaped molecular containers that can act as molecular hosts in the presence of specific guest molecules in water, and consequently self-assemble into host-guest inclusion complexes. Their versatility and exceptional molecular recognition properties have prompted researchers to utilize them for a variety of purposes such as protein conjugation, drug delivery, pharmaceuticals, and supramolecular polymerization. Here, we show that the recognition properties of CB[8] can be harnessed to prepare water-soluble metallosupramolecular polymers, and indeed sequence-specific polymers can be obtained in the presence of negative and positive monomers in solution. In the course of this study, we found that CB[n] can inhibit ligand exchanges in metal-ligand complexes. We also demonstrate that ditopic organic guests can self-assemble into short oligomers in the presence of CB[8], and possibly be used in protein-targeting dynamic combinatorial libraries.

Main-chain poly[n]catenanes are topological macromolecules constructed by mechanicallyinterlocking many small cyclic monomer rings into a long chain. The mechanical bonds provide alarge degree of freedom to the polymer backbone and poly[n]catenanes are predicted to haveexceptional molecular flexibility and robustness. However, the synthesis of main-chainpoly[n]catenanes has not been achieved. This dissertation will discuss the first successful syntheticapproach toward main-chain poly[n]catenanes, utilizing the ring-closing reaction of a preassembledmetallosupramolecular polymer (MSP) template from rationally designed componentswith an isolation yield of 75~80%. Nuclear magnetic resonance (NMR) and gel permeationchromatography-multiangle laser light scattering (GPC-MALLS) confirms the mechanicalinterlocking structure and high molecular weight of the polycatenanes. Further study shows theproduct is a mixture of linear, branched and cyclic polycatenanes, which can be separated by sizeexclusion chromatography. Progress toward increasing the yield of polycatenane synthesis andimproving the formation of linear polycatenane will also be described.

Over the last two decades, calix[4]pyrroles – teterapyrrolic macrocycle linked through α or meso-like positions by sp³-hybridized carbon atoms – have been exploited as strong and selective receptors and as extractants for both anions and ion pairs. In particular, complexation of an anion to calix[4]pyrrole via four hydrogen bonds drives conformational changes from the 1,3- alternate to the cone conformation. This conversion provides a concave, bowl-like cavity that permits recognition of charge diffuse cations, such as cesium and imidazolium, through cation– interactions. This structural flexibility is a characteristic of calix[4]pyrrole chemistry. The work described in this dissertation takes advantage of molecular switching phenomena. In particular, it details efforts to realize self-assembly using functionalized calix[4]pyrroles. In the context of theses efforts, a variety of secondary forces, such as hydrogen bonding interaction, - (CH-) interactions, and charge transfer (CT) interactions are exploited and studied in detail. Also included in this dissertation is a summary of studies of stimulus-responsive behavior, wherein systems constructed from calix[4]pyrroles are exposed to external stimuli that includes anions, acid/base, and electrochemical triggers. Chapter 1 gives a brief overview of the use of calix[4]pyrroles as molecular carriers stressing the transport of ion pairs. Chapter 2 details a multi-stage molecular equilibrium system that exploits two kinds of cali[4]pyrroles as well as appropriately chosen chemical inputs, and the conseqyent construction of a NAND logic gate. Chapter 3 describes factors that affect the self-assembly process under condition where the interactions are relatively weak. Chapter 4 focuses on orthogonal self-assembly from calix[4]pyrrole and a functionalized fullerene. Chapter 5 details formation of metal-containing 1D arrays and molecular capsules. Lastly, chapter 6 demonstrates the syntheses and the characterization data of all compounds used in these studies.

Supramolecular block copolymers, which are the supramolecular analog of covalently-bonded block copolymers, consist of individual polymer blocks connected by non-covalent bonds. They can be produced by self-assembly of telechelic oligomers or polymers with complementary end-groups, e.g., hydrogen bonding or acid-base interactions, such that a variety of block combinations may be achieved by simple mixing of the appropriate polymers. Supramolecular block copolymers are advantageous for fabricating nanostructured functional materials, since they can exhibit morphologies mimicking conventional covalently-bonded block copolymers and the reversible nature of the supramolecular bonds between blocks allows for unique responses to external stimuli. Various applications of these materials have been explored, such as self-healing, thermally tunable nanostructures, nanoporous materials, and nanostructured assemblies.In the first part, a supramolecular multiblock copolymer, was synthesized by mixing two telechelic oligomers, a,¿-sulfonated polystyrene, HO3S-PS-SO3H, derived from a polymer prepared by reversible addition-fragmentation chain-transfer (RAFT) polymerization, and a,¿-amino-polyisobutylene, H2N-PIB-NH2, prepared by cationic polymerization. During solvent casting, proton transfer from the sulfonic acid to the amine formed ionic bonds that produced a multiblock copolymer that formed free-standing flexible films with a modulus of 90 MPa, a yield point at 4% strain and a strain energy density of 15 MJ/m3. Small angle X-ray scattering characterization showed a lamellar morphology, whose domain spacing was consistent with the formation of a multiblock copolymer based on comparison to the chain dimensions. A reversible order-disorder transition occurred between 190°C and 210°C, but the sulfonic acid and amine functional groups decomposed at those elevated temperatures based on companion optical microscopy and spectroscopy measurements. For high non-linear strains, the dynamic modulus, G’, decreased by nearly an order of magnitude and the loss modulus, G”, decreased by a factor of 1.4, but both recovered to their original values once the strain was reduced to within the linear response region. In the second part, two groups of RAFT agents that contain either quaternary ammonium or quaternary phosphonium groups were prepared. At first, a series of trithiocarbonate RAFT agents containing quaternary ammonium functionality in the “R-group” (RAFT-NR3) were synthesized via a facile and high-yield approach. The synthetic route first involves the optimized synthesis of 4-(bromomethyl)-N,N,N-trialkyl benzyl ammonium bromide compounds, which were subsequently reacted with the alkyl trithiocarbonate anion to directly produce the trithiocarbonate RAFT agent. However, quaternary ammonium group partially degraded when the RAFT agents were used in polymerizations at 120 oC. This issue was overcome by using lower polymerization temperature. On the other hand, quaternary phosphonium-containing, trithiocarbonate RAFT agents (RAFT-PR3) were also synthesized via similar synthetic method. It was found that the thermal stabilities of RAFT-PR3 were enhanced compared to comparable quaternary ammonium-containing RAFT agents, which significantly improved the retention of the cationic end-functionality of the polystyrene obtained at 120 oC. For both classes of RAFT agents, the crude polystyrene can be further purified via column chromatography to afford high purity hemi-telechelic cationomers.In the third part, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-ToF MS) was used to quantify the sulfonation level and sulfonation distribution of sulfonated polystyrene ionomers prepared by homogeneous solution sulfonation. The sulfonation levels obtained by MALDI ToF-MS and acid-base titration were compared, and the sulfonate distributions determined by MALDI-ToF MS were compared with theoretical random distributions. The results indicate that the sulfonation reaction used produces a sample with a random sulfonate distribution.

Block copolymers consist of two or more incompatible polymer chains linked by covalent bonds. These block copolymer can separate into nanometer sized domains whose morphology depends upon the size of the block and interactions between them. The properties of block copolymers can be modified and potentially improved by introducing noncovalent interactions to replace covalent linkages between blocks to form supramolecular block copolymers. These kinds of materials combine the microphase separation inherent to block copolymers with the facile synthesis of supramolecular materials thereby affording new and unique materials. This dissertation focuses on synthesis and characterization of PS-b-PMA block copolymers with ion-pair junctions.Firstly, the chain-end sulfonated polystyrene (¿-sulfonated PS) was synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization and postpolymerization modification. In the postpolymerization modification two methods were investigated: in the first one, the polymer was converted to a thiol-terminated polymer by aminolysis. Then a sulfonic acid end-group was produced then by oxidation of the thiol end-group with m-chloroperoxybenzoicacid (m-CPBA); in the second method, the RAFT-polymerized polymer was directly sulfonated by oxidation with m-CPBA. After purification by column chromatography, ¿-sulfonated PS was obtained by both methods with greater than 95% end-group functionality as measured by titration. The sulfonic acid end-group could be neutralized with various ammonium or imidazolium counter ions through acid–base or ionic metathesis reactions. These polymers with ionic end-group can be used as model supramolecular building blocks.Secondly, ammonium end functionalized polymethylacrylate (PMA) was synthesized directly by RAFT polymerization using functional RAFT agent. Then chain-end sulfonated polystyrene and ammonium end functionalized polymethylacrylate (PMA) were used to synthesize A-B block copolymers by two different methods: the first method was by mixing two oppositely charged end group functionalized polymers; the second method was to ionically bond a RAFT agent to the chain end of an end sulfonated polymer to generate a supramolecular macro RAFT agent then an A-B block copolymer was prepared by RAFT polymerization using supramolecular macro-RAFT agent. The polymerization kinetics were investigated and the molecular weight and the chemical structure of the block copolymers were characterized by 1H-NMR and SEC. The results show that the ion-bonded supramolecular block copolymer, PS-PMA, have been successfully prepared with controlled molecular weight and narrow distribution.Thirdly, the morphology of the ion-bonded supramolecular PS-PMA diblock copolymers were investigated by small-angle X-ray scattering (SAXS) and rheological techniques. Several covalently bonded PS-PMA block copolymers were synthesized by RAFT polymerization and their micro domain structures and rheology behaviors were also investigated. The results showed that the electrostatic interactions between the end ion groups are able to overcome the thermodynamic repulsion of two blocks result in the formation of diblock copolymers with similar behaviors and morphology of traditional covalent bonded diblock copolymers and their micro domain structures remain to high temperatures.

Design and preparation of novel host/guest systems, such as pseudorotaxanes, semirotaxanes, rotaxanes and catenanes, with high association constants, enhanced yields and the abilities to respond to external stimuli are of great importance and significance due to their topological novelty and potential application. The convergence of supramolecular chemistry with polymer science provides an important way to extend the scope of polymer and material sciences by incorporating designed host/guest systems into polymers, and the resulting non-covalently linked supramolecular polymers are expected to have unusual properties due to their unique architectures compared with traditional polymers. After discovery of bis(meta-phenylene)-32-crown-10 (BMP32C10) derivative/paraquat complexes, for about a quarter century only “taco”-shaped complexes were observed by X-ray crystallography. Here, by the self-assembly of a BMP32C10 bearing two electron-donating groups (carbazoles) with electron-accepting paraquat derivatives, the first [2]pseudorotaxane and the first pseudocryptand-type poly[2]pseudorotaxane based on BMP32C10 were isolated as crystalline solids as shown by X-ray analyses. The first dual component pseudocryptand-type [2]pseudorotaxanes were designed and prepared via the self-assembly of synthetically easily accessible BMP32C10 pyridyl, quinolyl and naphthyridyl derivatives with paraquat. The formation of the pseudocryptand structures in the complexes remarkably improved the association constants by forming the third pseudo-bridge via H-bonding with the guest and π-stacking of the heterocyclic units. A pseudocryptand-type [2]pseudorotaxane was formed via the self-assembly of a dipyridyl BMP32C10 derivative and a paraquat derivative. Due to the basicity of the pyridyl group, which forms the third pseudo-bridge of the pseudocryptand, this pseudorotaxane represents the first system with acid-base adjustable association constants, i. e., finite both under acidic and neutral conditions. The first pseudocryptand-type supramolecular [3]pseudorotaxane was designed and prepared via the self-assembly of a bispicolinate BMP32C10 derivative and a bisparaquat. The complexation behavior was cooperative. In addition, the complex comprised of the BMP32C10 derivative and a cyclic bisparaquat demonstrated strong binding; interestingly, a poly[2]pseudocatenane structure was formed in the solid state for the first time. Two novel BMP32C10 cryptands, bearing covalent and metal complex linkages, were designed and prepared. By employing the self-assembly of these biscryptands, which can be viewed as AA monomers, and a bisparaquat, which can be viewed as a BB monomer, the first AA/BB-type linear supramolecular polymers with relatively high molecular weights were successfully prepared. Via the self-assembly of two BMP32C10-based cryptands, bearing covalent and metal complex (ferrocene) linkages, with dimethyl paraquat, novel [3]pseudorotaxanes were formed statistically and anticooperatively, respectively. From a hydroxyl-functionalized secondary ammonium salt a [2]semirotaxane and a [2]rotaxane were prepared successfully with dibenzo-24-crown-8 (DB24C8). X-ray analysis of a single crystal of the [2]semirotaxane confirmed its semirotaxane nature. In addition, the formation of the [2]semirotaxane can be reversibly controlled by adding KPF6 and 18C6 sequentially. This system affords a way to prepare novel supramolecular polymers. Dibenzo-30-crown-10 (DB30C10) derivatives and pyridine-based DB30C10 cryptands were prepared by employing the templating method established by our group. A [2]pseudorotaxane was prepared based on DB30C10 diol and paraquat diol. The [3]pseudorotaxane formed via the self-assembly between DB30C10 cryptand and bisparaquat diol occurred in a cooperative manner. In addition, a bromo-functionalized DB30C10 cryptand was successfully designed and prepared. An alkyne-functionalized DB30C10 cryptand was designed and is under preparation; its precursors have been prepared successfully. In the future, based on these functionalized cryptands and paraquat salts, AA and AB type monomers will be prepared. Via the self-assembly between these monomers, non-covalent supramolecular polymers with high molecular weight will be afforded. A novel DB30C10 cryptand bearing an organometallic bridge, ferrocene, was prepared via 1-(3'-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI) coupling of the crown ether diol with ferrocene dicarboxylic acid. The cryptand is dimerized in the solid state via π, π-stacking and hydrogen bonds. The ferrocene-based cryptand formed novel [2]pseudorotaxanes with paraquat and diquat PF₆ salts with association constants (Kₐ) of 1.7 ± 0.1 x 10³ and 4.2 ± 0.3 x 10⁴ M⁻¹ in acetone-d₆, respectively. In order to prepare linear polycatenanes, the preparation of which represent a real synthetic challenge, a series phenanthroline derivatives were designed and prepared. A “U” shaped monomer was successfully prepared in relative high yield with good solubility. In the future, real linear polycatenanes will be prepared. In addition, a novel diphenanthroline-based BMP32C10 derivative was prepared in high yield and the complexation behavior between it and dimethyl paraquat was studied.

We studied the self-assembly dynamics of two polymeric systems, block copolymer micelles and supramolecular polymer solutions using computer simulation.Dissipative Particle Dynamics simulations were applied to study the equilibrium properties, kinetics of micellization and equilibrium chain-exchange in A2B3 and A4Bx(x=4,6,8) diblock copolymer micelle solutions. The critical micelle concentration, micelle aggregation number distribution and micelle structure were found to agree well with previous experimental and theoretical studies. The time-evolution of micelles from unimers is found to follow three stages: unimer consumption, equilibration of the number of micelles progressing mainly by the fusion/fission mechanism and slow adjustment of the weight-average aggregation number by micelle fusion, unimer and small aggregate exchange. The effect of polymer concentration, hydrophobic interaction energy and block length on the kinetics of micellization were also considered. By performing micelle hybridization simulations, we found the equilibrium chain exchange follows a first-order kinetic process and the characteristic time, mainly determined by chain expulsion and does not depend on polymer concentration. The chain exchange characteristic time, τ, increases exponentially with core block length, NA and interaction parameter between blocks, χAB as τ ~ exp(0.67χABNA). We also found that in contrast to theoretical predictions, chain exchange between micelles occurs more rapidly for micelles with a longer corona-block length due to a higher compatibility of diblock copolymers and therefore a lower potential barrier for chain expulsion.Using coarse-grained molecular dynamics simulations we studied the equilibrium and rheological properties of dilute and semi-dilute solutions of head-to-tail associating supramolecular polymers with our newly-developed model for spontaneous reversible association. We found that for a given spacer length all shear-rate-dependent reduced viscosity data collapse into one master curve with two power-law regions with increasingslopes due to change of the degree of self-assembling under shear. The equilibrium viscosity is found to obey a power-law scaling dependence with exponent 1.5 on oligomer volume fraction, in agreement with experimental observations for several dilute or semi-dilute solutions of supramolecular polymers, implying that dilute and semi-dilute supramolecular polymer solutions exhibit high polydispersity, but may not be sufficientlyentangled to follow the reptation mechanism of relaxation, expected for wormlike micelles.

Supramolecular chemistry has become a rapidly growing field since the Nobel Prize was awarded to the work of Lehn, Pedersen, and Cram in 1987 for their pioneering work on crown ethers and non-covalent host-guest interactions. Metal-ligand interactions represent a particularly useful and well-studied means of preparing supramolecular polymers from telechelic building blocks. This present work focuses on utilizing main-chain metallo-supramolecular polymers or small molecules, based on 2,6-bis(1’-methylbenzimidazolyly)pyridine (Mebip) ligands, to create materials aimed at applications such as light healable polymers, or the detection of chemical warfare agents.With the objective to develop new organic/inorganic hybrid materials, which combine good mechanical properties and other attractive properties with ease of processing, new classes of metallo-supramolecular polymers were explored. The general design approach merged the structure of known polymer systems, for example semiconducting polymers (poly(p-phenylene ethynylene)s) or thermally stable hydrocarbons (poly(p-xylyene)s), with the advantages of a dynamic (reversible) polymerization process, to allow access to materials that are otherwise difficult to process. The new telechelic metallo-supramolecular polymers could be readily solution-processed and represent illustrative examples for metallo-supramolecular polymers with good mechanical properties, while maintaining the properties of parent polymer. Polymers with the ability to repair themselves after sustaining damage are poised to extend the lifetime of materials used in a wide range of applications. Reported here is the development of metallo-supramolecular polymers that can be mended through exposure to light. Upon exposure to ultraviolet light, the metal-ligand motifs are electronically excited and the absorbed energy is converted into heat, causing reversible disengagement of the metal-ligand motif and a temporary reduction in the molecular weight. As a result, defects heal quickly, with high efficiency, and if needed repeatedly. A modular sensory system, for the detection of organophosphates, which utilizes a multi-metal/multi-ligand approach is presented. The sensing scheme relies on fluorescent sensor complexes of Mebip ligands and selected metal ions. Detection of organophosphates is accomplished through competitive coordination of the analyte with the metal. Mixing and matching consciously designed ligands and carefully selected metal ions allows the formation of sensor complexes, which allow organophosphate detection with high selectivity and sensitivity.

Production of efficiently synthesizable, strongly associating crown ether-based cryptands is desired for pseudorotaxane complexation of bipyridinium guests to produce suprapolymers and supramolecularly-linked block copolymers. Cryptands based on bis(meta-phenylene)-32-crown-10 (BMP32C10) were synthesized. The functionality of phenylenemethanol-BMP32C10 cryptand III-3 (Ka = 2.0 x 104 M-1) did not negatively affect binding strength, although the strength of complexation is marginal to achieve the desired suprapolymers. The cryptand dimethylpyridyl-BMP32C10 IV-2 was synthesized in an attempt to improve over the binding ability of the pyridyl-BMP32C10 cryptand IV-1; instead, interesting host design insights were discovered as binding strengths were reduced over 1000-fold. The crystal structure of IV-2 shows acyl-aryl conjugation which limits the host's ability to accept guests. Synthesis of larger cis-di(carbomethoxybenzo)-3n-crown-n crown ethers was explored using the high concentration, template technique previously reported for cDB24C8 diester. cDB30C10 diester (V-1c) was produced in 93% yield; the desired pyridyl-cDB30C10 cryptand V-12 binds paraquat strongly (Ka = 1-2x105 M-1) and diquat stronger than any other host (Ka = 1.9x106 M-1), both in 1:1 fashions; association constants were measured by ITC. X-ray crystallography of the complexes shows the cryptand's para arm is too far away to interact with paraquat and the host has numerous bifurcated interactions with diquat, explaining the difference in binding strengths. Syntheses of the regioisomers of cDB27C9 diester was also explored; the cyclization yields (cDB27C9S, VI-2: 59% and cDB27C9L, VI-3: 44%) are lower, likely due to poor attack angles due to mismatched arm length in cyclization, than the equivalent length ethyleneoxy-armed cDB24C8 and cDB30C10. Modeling of the cryptand isomers, pyridyl-cDB27C9S and pyridyl-cDB27C9L, showed that the former should improve para arm interaction with paraquat, but should be sterically hindered for diquat and the latter should have a highly flexible, poorly preorganized interaction with either type of guest. ITC, MS, and crystallography data supported the predictions. Derivatization of the pyridyl-cDB30C10 cryptand V-12 was explored using chelidamic acid (VII-1). Schemes yielding alcohol, alkyl halide, alkyne, and TEMPO functionality were followed, but failed. Currently, functionalized cryptand derivatives have not been achieved, future directions are proposed.

The objective of this research is to use low DP poly(p-benzamide) (PBA) segments, terminated by units forming supramolecular bonds, able to extend the overall DP of the aromatic polyamide. PBA fibers, and the related industrially produced PPTA (Kevlar), exhibit their most interesting ultra-high strength properties only when a considerably large DP (>100) is attained. Use of cumbersome and expensive syntheses and solvents are required to attain DP in the range (~200-300) of industrial interest. Moreover, the fully covalent polymers thus far produced are highly insoluble in common organic solvents. On the other hand, easier processing becomes feasible if the DP of conventional PBA (prepared by the Yamazaki reaction) is increased by supramolecular bonding through ionic or hydrogen bond interactions. The effects of three different binding methods were first investigated on short rigid monomers with promising results the same binding was then used on rigid segments of PBA. The binding methods used two diamine binders triethylenediame (TED) and bipiperidine (Bipip) to form ionic bonds with the monomer, and polymer segments. The last method utilized a 2(6-iso cyanato hexylamino carbonyl amino)-6-methyl-4[1H]pyrimidinone (Upy) end group covalently bonded to the PBA polymer. This end group has the ability to form 4 hydrogen bonds with itself and thus could be used to increase the overall DP of the polymer starting material. This is believed to be the first recorded hydrogen bonded supramolecular interaction in amide type solvents. The novel and revolutionary idea of using low DP segments of PBA to increase the overall DP of polymer could be an industrially viable way to produce the highly sought after industrial polyamides.

Supramolecular host-guest chemistry is a topic of great current interest. However, the further development of host-guest chemistry is still limited by the number of available host-guest recognition motifs. This makes it necessary and valuable to find new host-guest recognition motifs and apply known host-guest recognition motifs in the preparation of novel supramolecular systems. By comparing the crystal structures of the host and its taco complex, we proved that folding is a necessary step during the formation of taco complexes. Based on the known bis(m-phenylene)-32-crown-10/paraquat recognition motif, the first solid-state supramolecular poly(taco complex) was prepared. We demonstrate not only that bis(m-phenylene)-32-crown-10-based cryptands are powerful hosts for paraquat derivatives compared with the simple crown ether, but also that cooperative complexation can be obtained with the cryptand structure. It was shown that the significant improvement in complexation was the result of the combination of the preorganization of the cryptand hosts and the introduction of additional and optimized binding sites. Furthermore, it was demonstrated that improved complexation of bis(secondary ammonium) and bisparaquat salts could also be achieved by the formation of the pseudocryptand structure. We also prepared two dimers of inclusion cryptand/paraquat complexes driven by dipole-dipole and face-to-face p-stacking interactions. An interesting complex based on dibenzo-24-crown-10 and diquat was prepared. In its crystal structure the diquat guest lies in the concave cavity provided by two dibenzo-24-crown-8 hosts. Monopyridinium-based [2]- and [3]-pseudorotaxanes were prepared based on the newly discovered bis(m-phenylene)-32-crown-10/monopyridinium salt and cryptand/monopyridinium salt recognition motifs. Inspired by the formation of solid-state taco complexes between bis(m-phenylene)-32-crown-10 and paraquat derivatives, we designed and synthesized the first cylindrical bis(crown ether) host for paraquat derivatives and studied its complexation with paraquat. We prepared three slow-exchange C3-symmetric inclusion complexes based on a newly discovered cryptand/trispyridinium recognition motif, in which 1,3,5-trispyridiniumbenzene salts act as guests. Finally the application of several new and known recognition motifs in the preparation of a supramolecular poly[3]pseudrotaxane, and the first pseudorotaxane-type supramolecular star-shaped polymer, and the first supramolecular hyperbranched polymer was discussed.