87 results about "Bond cleavage" patented technology

We have designed a molecular switch based on the photoinduced opening and thermal closing of a [1,3]oxazine ring. A substituted [1,3]oxazine compound described as having a general (i.e., unsubstituted) structure with fused indoline and benzooxazine fragments such that they share a common bond in the [1,3]oxazine compound: (i) the bond connecting positions 1 and 2 of the indoline fragment and (ii) the bond connecting positions 2 and 3 of the benzooxazine fragment. Irradiation by light of suitable wavelength and intensity of this photochromic compound induces cleavage of a [C—O] bond of the [1,3]oxazine ring to form a phenolate chromophore. The photogenerated (e.g., colored) isomer may revert thermally to the starting (e.g., colorless) oxazine. Alternatively, the switch may be between isomers of the compound that absorb at different wavelengths. Reversible coloration of silica or polymeric materials and switching optical signals may involve many cycles of interconversion between different colored states. A colorless / colored state may be maintained by constant irradiation or chemical trapping.

To provide a method of producing a polyoxyalkylene-modified polysiloxane composition that is free of acid-mediated carbon-oxygen bond and silicon-oxygen bond cleavage, that is substantially deodorized and also does not generate odor with elapsed time, and that is therefore well suited for use in cosmetic applications, e.g., for hair cosmetics, skin cosmetics, and so forth. A production method of this invention is characterized by removing the odor-causing substance from a polyoxyalkylene-modified polysiloxane composition that has been synthesized by a hydrosilylation reaction, by subjecting the polyoxyalkylene-modified polysiloxane composition to a hydrolysis treatment in the presence of an acidic inorganic salt that is a solid at 25 DEG C and gives a specific pH at 25 DEG C in aqueous solution; for example, potassium hydrogensulfate.

To provide a method of producing a polyoxyalkylene-modified polysiloxane composition that is free of acid-mediated carbon-oxygen bond and silicon-oxygen bond cleavage, that is substantially deodorized and also does not generate odor with elapsed time, and that is therefore well suited for use in cosmetic applications, e.g., for hair cosmetics, skin cosmetics, and so forth. A production method of this invention is characterized by removing the odor-causing substance from a polyoxyalkylene-modified polysiloxane composition that has been synthesized by a hydrosilylation reaction, by subjecting the polyoxyalkylene-modified polysiloxane composition to a hydrolysis treatment in the presence of an acidic inorganic salt that is a solid at 25° C. and gives a specific pH at 25° C. in aqueous solution; for example, potassium hydrogensulfate.

A method and system for calculating the free energy difference between a target state and a reference state. The method includes determining one or more intermediate states using a coupling parameter, performing molecular simulations to obtain ensembles of micro-states for each of the system states, and calculating the free energy difference by an analysis of the ensembles of micro-states of the system states. The method can be particularly suited for calculating physical or non-physical transformation of molecular systems such as ring-opening, ring-closing, and other transformations involving bond breaking and / or formation. A soft bond potential dependent on a bond stretching component of the coupling parameter and different from the conventional harmonic potential is used in the molecular simulations of the system states for the bond being broken or formed during the transformation.

Disclosed is a silver halide photographic light-sensitive material comprising at least one silver halide emulsion layer on a support, which contains a compound of which one-electron oxidized derivative produced by one electron oxidation of the compound is capable of releasing two or more electrons with a bond cleavage and has a characteristic curve drawn in orthogonal coordinates of logarithm of light exposure (x-axis) and optical density (y-axis) using equal unit lengths for the both axes, on which gamma is 5.0 or more for the optical density range of 0.3-3.0. This silver halide photographic light-sensitive material shows high contrast and high sensitivity.