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The self-assembly of block polymers into well-ordered nanostructures underpins their utility across fundamental and applied polymer science, yet only a handful of equilibrium morphologies are known with the simplest AB-type materials. Here, we report the discovery of the A15 sphere phase in single-component diblock copolymer melts comprising poly(dodecyl acrylate)−block−poly(lactide). A systematic exploration of phase space revealed that A15 forms across a substantial range of minority lactide block volume fractions (f L = 0.25 − 0.33) situated between the σ-sphere phase and hexagonally close-packed cylinders. Self-consistent field theory rationalizes the thermodynamic stability of A15 as a consequence of extreme conformational asymmetry. The experimentally observed A15−disorder phase transition is not captured using mean-field approximations but instead arises due to composition fluctuations as evidenced by fully fluctuating field-theoretic simulations. This combination of experiments and field-theoretic simulations provides rational design rules that can be used to generate unique, polymer-based mesophases through self-assembly.

This thesis describes the synthesis and characterization of a new family of fluorescent and redox-active BF2 complexes of formazanate [R1-N-N=C(R3)-N=N-R5]− ligands. The complexes were easily synthesized in two high-yielding steps, from inexpensive starting materials and readily purified by conventional methods. The properties of the resulting complexes can be tuned through structural variation – for example, appending electron donating or withdrawing substituents, or extending π conjugation. These methods of structural variation can bathochromically or hypsochromically shift the maximum absorption and emission wavelengths, vary the quantum yields, and allow for tuning of the reduction potentials. Using these methods, the properties of these complexes were optimized for use as fluorescence cell-imaging agents, and efficient electrochemiluminescence emitters.In order to expand the scope of this chemistry, copper-assisted azide-alkyne cycloaddition (CuAAC) chemistry was used to further modify the BF2 formazanate scaffold. Using this method, benzyl groups were appended to the BF2 complexes, which showed that the reaction proceeded cleanly, and that the resulting products had red-shifted wavelengths of maximum absorption and emission, and increased fluorescence quantum yields. Using the same strategy, a tetraethylene glycol based azide imparted water solubility, and the resulting complex was used in fluorescence cell-imaging experiments. Additionally, ferrocene moieties could be appended, which quenched the fluorescence of the resulting complex. Upon oxidation of the ferrocene groups, the fluorescence was regenerated allowing for these compounds to be used as redox sensors. Finally, CuAAC was used to synthesize copolymers of BF2 formazanate complexes and 9,9-dihexylfluorene. The resulting polymers had low band gaps (Eg = 1.67 eV) and good film-forming properties, paving the way for their use in organic photovoltaics.Finally, reaction of an o-phenol-substituted formazan with BF3•OEt2 and NEt3 resulted in a complex reaction mixture, which contained 5 BN heterocycles with unprecedented connectivity and interesting optical and electronic properties. Two of the most unique complexes were selected, and their chemical reduction products – a stable anion, radical anion and diradical dianion were studied in detail.Combined, this work has opened up an entirely new area of molecular materials with application in a variety of fields. This thesis describes the details of the work described above.