Single-walled carbon nanotubes (SWNTs) are encapsulated with microenvironments of nonpolar solvent, providing a new method to measure the photophysical properties of nanotubes in environments with known properties. Photoluminescence (PL) and absorbance spectra of SWNTs show solvatochromic shifts in 16 nonpolar solvents, which are proportional to the solvent induction polarization. The shifts in...

We present semiempirical AM1 calculations for the ground and excited state of 2-naphthol and some of its cyano derivatives in the gas phase. Following photoexcitation, the Mulliken electron density on the oxygen diminishes slightly for the acid and more conspicuously for the anionic conjugated base. This agrees with the measured solvatochromic parameters for 2-naphthol. In both electronic state...

The ability to detect biodiesel at various concentrations in diesel is an important goal in several industries. A simple, solvatochromic dye-doped optical sensor is presented for quick and direct detection of 0.5 ppm-20% v/v FAME/biodiesel in diesel.

Spectroscopic properties of amino-analogs of luciferin and oxyluciferin were investigated to confirm the color modulation mechanism of firefly (beetle) bioluminescence. Fluorescence solvatochromic character of aminooxyluciferin analogs indicates that the bioluminescence of aminoluciferin is useful for evaluating the polarity of a luciferase active site.

Rational design of small molecular gelators is an elusive and herculean task, despite the rapidly growing body of literature devoted to such gels over the past decade. The process of self-assembly, in molecular gels, is intricate and must balance parameters influencing solubility and those contrasting forces that govern epitaxial growth into axially symmetric elongated aggregates. Although the ...

The protonation constants of glycine, L-alanine, glycyl-glycine, glycyl-glycyl-glycine and glycyl-L-alanine have been determined in 10-80% (v/v) ethanol-water mixtures at 25 °C and constant ionic strength (0.1 mol L-1 sodium perchlorate), by potentiometric technique and calculated using a suitable computer program, which employs a nonlinear least-squares method. The effect of solvent compositio...

The absorption and fluorescence spectra of 7-dimethylamino cyclopenta [c] coumarin (C138) and 4-methyl-piperidino [g] coumarin (C339) dyes were measured in neutral, aprotic and protic solvents. Solvatochromic shifts of absorption and fluorescence as a function of different solvent polarity parameters (bulk as well as microscopic) were analyzed for these dyes and the ground state dipole moment (...

BACKGROUND For the development of properties in molecular crystals, such as electrical conductivities, magnetic properties, or non-linear optical properties, not only the electronic properties of molecules themselves matter, but also the molecular arrangements in the crystals are very important. Therefore, the design of the crystal structures and the control of molecular arrangements have attra...

The excited-state dynamics of two donor-acceptor biaryls that differ by the strength of the acceptor, a pyridinium or a pyrylium moiety, have been investigated using a combination of steady-state solvatochromic absorption, ultrafast fluorescence, as well as visible and infrared transient absorption spectroscopies. The negative solvatochromic behavior of pyridinium phenolate indicates that the p...

Optical absorption and fluorescence emission spectral studies of acridine in different solvents namely, carbon tetrachloride, dichloromethane, propan-2-ol, ethanol, methanol, acetonitrile, and N,Ndimenthyl formamide have been investigated. Oscillator strength and transition dipole moment of the acridine have been elucidated from the optical absorption measurement. The ratio of the excited state...