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Self-assembly and photophysical propertiesof a trialkoxybenzhydrazide-functionalizednaphthalene diimide (NDI)-appended amphiphilic polymer are reported.Hydrophobically assisted H-bonding among hydrazides in conjunctionwith π-stacking among NDI produced vesicles in aqueous mediumwith astonishingly high kinetic as well as thermodynamic stabilitywhich showed enhanced emission in the aggregated state. In benzene,rarely reported reverse vesicular assembly was formed with dual containerproperty with almost identical photophysical properties and stabilityas observed in water. Both vesicular and reverse-vesicular assemblieswere found to remain stable at the benzene–water interface. [ABSTRACT FROM AUTHOR]

Synthesis of an end-functionalized polylactide by ring-openingpolymerization of lactide monomer using a functional initiator containingpyridyl disulfide group is reported. Molecular weight of the polymerdetermined by GPC matched very well with that determined by end-groupanalysis using the UV/vis method, suggesting survival of the end-groupfunctionality during polymerization. DTT-induced reduction of thepyridyl disulfide group produced free sulfhydryl group quantitativelywhich was utilized for versatile chain-end modifications using variousthiol-mediated high-yielding chemical transformations including thiol–ene,thiol–maleimide, and thiol–acrylate “click”reactions. This strategy was further extended to link two macromoleculesby reaction of sulfhydryl-functionalized polylactide and acrylate-terminatedpoly(ethylene oxide) (PEO) which produced a block copolymer with anacid-labile β-thiopropionate linker between the two constituentblocks. This functional group could be cleaved under mild acidic conditionto produce the individual parent polymers. Further as-synthesizedpyridyl disulfide-terminated polylactide was treated with thiol-functionalizedsugar moiety and n-type semiconducting naphthalene diimide (NDI) chromophorewhich also generated quantitative chain-end functionalization by thiol–disulfideexchange reaction. NDI-functionalized polylactide showed white lightemission due to mixed emission from monomeric and excimer-type species.Further atomic force microscopic (AFM) studies revealed NDI-functionalizedpolymer formed uniform spherical aggregates upon drying of a drop-castedfilm on silicon surface possibly due to solvent-evaporation-induceddefined organization of the polymer chain dictated by strong π-stackinginteraction among the NDI chromophores. [ABSTRACT FROM AUTHOR]