To obtain insight into the effects of the environment on the photophysics and photochemistry of the green fluorescence protein (GFP), eight crystal structures of six synthetic aryl-substituted analogues (2-fluoro, 2-methyl, 3-hydroxy, 3-methoxy, 2,4-dimethyl and 2,5-dimethyl) of the GFP chromophore (4-hydroxy-benzylidenedimethylimidazolinone) were determined and correlated with their two-dimensional steady-state and time-resolved solid-state excitation-emission spectra. The stacking between the molecules greatly affected the emission energy and the lifetime of the emission of the chromophore, implying that pi-pi interactions could be critical for the photophysics of GFP. The reaction pathways were dependent on the excitation energy, resulting either in [2 + 2] photodimerization at the bridging double bond (UV excitation) or flipping of the imidazolone ring (visible excitation). The meta-hydroxy chromophore (3-HOBDI) was the only GFP-chromophore analogue that was obtained as more than one stable polymorph in the pure state thus far. Due to the asymmetric substitution with hydrogen bond donors and acceptors, 3-HOBDI is tetramorphic, the forms showing distinctly different structure and behavior: (1) while one of the polymorphs (3-HOBDI-A), having multilayer structure with alternating stereochemistry of linear hydrogen-bonded motifs, undergoes photodimerization under UV light, (2) another (3-HOBDI-C), which has dimeric head-to-tail structure, shows Z-to-E isomerization via tau-one-bond flip of the imidazolone ring by excitation in the visible region. X-ray diffraction analysis of a partially reacted single crystal of 3-HOBDI-C provided the first direct evidence of tau-one-bond flip occurring in a GFP-like compound. Moreover, the cooperative action of the photodimerization of 3-HOBDI-A appears as a photomechanical effect of unprecedented magnitude for a single crystalline specimen, where photoexcited single crystals bend to more than 90 degrees without breaking.

Enhancement of the specific capacitance in electrochemical double layer capacitors (EDLCs) is of high interest due to the ever increasing demand for high power density energy storage devices. Zeolite templated carbon (ZTC) is a promising EDLC electrode material with large specific surface area and straight, ordered well-defined micropores. In this study, ZTC samples were synthesized using a low pressure chemical vapor deposition (LP CVD) of carbon on sacrificial zeolite Y powder using acetylene gas as a precursor. We demonstrate for the first time how various post-treatments of the produced samples can affect the ZTC microstructure and porosity and how such modifications may significantly improve electrochemical performance characteristics of the ZTC-based EDLC electrodes. The effects of CO 2 activation, ball milling and high temperature annealing process were systematically studied. The best performing samples achieved very large capacitance of over 240 Fg −1 at 1 mVs −1 in 1 M solution of tetraethylammonium tetrafluoroborate in acetonitrile and stable performance in symmetric EDLC devices with no noticeable degradation for over 20,000 cycles at a very high current density of 20 Ag Electrochemical double layer capacitors (EDLCs), also called supercapacitors and ultra-capacitors, have attracted extensive attention as EDLCs can provide high power delivery or update, high cycle efficiency, thermal stability, practically unlimited cycle life and relatively low cost of manufacturing.1 Furthermore, a wide operational temperature range and a relatively easy determination of the state of charge can be considered as additional advantageous aspects.1 Hence, there is an increasing growth in demand for EDLCs in industrial equipments, electronic devices, transportation market, and automotive applications.1-5 Yet, significantly smaller energy density (ca. 5 Wh kg −1 ) compared to the state of art rechargeable Li ion batteries (ca. 180 Wh kg −1 ) urgently calls for improvement in capacitance of EDLCs. 6,7 In addition, for some applications it is crucial to further increase the charge-discharge rate capability without deteriorating energy density characteristics. 1The value of the double layer capacitance formed at the electrode/ electrolyte interface (which directly impacts the energy density of EDLCs) is believed to depend on multiple factors, such as specific surface area (SSA) of the electrically conductive porous carbon electrodes, 1,8-11 pore size distribution (PSD) of the carbon electrodes (which may affect both the pore access by electrolyte ions and the solvation shell distortion and the resulting pore wall -ion separation distance), 1,3,9,12 electron density of states in carbon (which may affect the capacitance of the electrode side of the double layer), 13 electrolyte-carbon interfacial energy (which may affect electrolyte wetting in both large and sub-nm sized pores), 14,15 electrolyte-carbon interactions (which may impact electron density of states in carbon), 16 the presence of doping species within carbon (which...

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