The present disclosure discloses a dye for industrialization of dyeing cotton fiber in supercritical carbon dioxide that can react with cotton fiber, wherein a preparation method therefor comprises the following steps: dissolving a hydroxyl-containing natural dye in an organic solvent, dropwise adding an alcohol compound containing a halogen group into a reaction system in the presence of an acid-binding agent, precipitating the product with another solvent after the reaction is completed, and then filtrating and drying to obtain the compound described. The obtained compound is used for dyeing cotton fiber in supercritical carbon dioxide. The dye provided by the present disclosure is capable of dyeing cotton fiber in supercritical carbon dioxide conditions, and has a better color fastness while dyeing the cotton fiber.

An optical filter includes an absorption layer containing a near-infrared absorbing dye with an absorption characteristic in dichloromethane satisfying (i-1) to (i-3). (i-1) In an absorption spectrum of a wavelength of 400 to 800 nm, there is a maximum absorption wavelength .sub.max in 670 to 730 nm. (i-2) Between a maximum absorption coefficient .sub.A of light with a wavelength of 430 to 550 nm and a maximum absorption coefficient .sub.B of light with a wavelength of 670 to 730 nm, the following relational expression: .sub.B/.sub.A65 is established. (i-3) In a spectral transmittance curve, the difference between a wavelength .sub.80 with which the transmittance becomes 80% on a shorter wavelength side than the maximum absorption wavelength with the transmittance at the maximum absorption wavelength .sub.max set to 10% and the maximum absorption wavelength .sub.max is 65 nm or less.

The present invention relates to: a novel merocyanine-based compound which exhibits a fluorescence signal at a visible light region of at least 380 nm, and which may be used for detecting biomolecules; and a biomolecular labeling dye, kit and contrast agent composition comprising the same.

The invention provides a novel class of cyanine dyes that are functionalized with sulfonic acid groups and a linker moiety that facilitates their conjugation to other species and substituent groups which increase the water-solubility, and optimize the optical properties of the dyes. Also provided are conjugates of the dyes, methods of using the dyes and their conjugates and kits including the dyes and their conjugates.

A reverse photochromic compound of the related art has difficulty in sensing light with a wavelength of 600 nm or greater in a visible light region which has been used for medical applications. Therefore, an object of the present invention is to provide a reverse photochromic compound and a polymer which have a high sensitivity to light having a wavelength of 600 nm or greater. The present invention relates to a compound and the like represented by the following general formula (1). ##STR00001## In the formula, R.sub.1 and R.sub.4 each independently represent a hydrogen atom or the like, R.sub.2, R.sub.3, and R.sub.5 each independently represent an alkyl group or the like, R.sub.6 represents a group having a polymerizable unsaturated group, a carboxy group, or an alkoxycarbonyl group, R.sub.31 and R.sub.32 each independently represent an alkoxy group or the like, R.sub.33 and R.sub.34 each independently represent a hydrogen atom or the like, Y.sub.1 represents an oxygen atom or a sulfur atom, An.sup. represents an anion, n.sub.1 to n.sub.3 represent a specific integer, and R.sub.1 and R.sub.2, R.sub.3 and R.sub.4, and/or R.sub.33 and R.sub.34 may form an alkylene group.

Fluorescent chromophores nicknamed BOPHY are provided. The chromophores may be readily synthesized in two steps from readily available reagents via the coupling of a pyrrole aldehyde or ketone with hydrazine, followed by reaction with BF.sub.3. The resultant symmetric and dimeric tetracycle is comprised of two BF.sub.2 units in six-member chelate rings, appended by pyrrole units on the periphery. The quantum yield of fluorescence for the unmodified compound and the tetramethyl variant are near unity, with values 95 and 92% respectively in CH.sub.2Cl.sub.2.

An organic dye corresponding to one of the following structures (I) or (II): eD-pi-conjugated chromophore-L-A (I), or A-L-pi-conjugated chromophore-eD (II), where eD represents an electron donor segment, L represents a covalent bond or a spacer segment and in particular a pi-conjugated spacer segment, A represents an electron acceptor segment capable of forming a covalent bond with a semiconductor, in which the pi-conjugated chromophore comprises at least one unit of formula (III): ##STR00001##
in which the radicals R1 and R2, which are identical or different, represent an optionally substituted aryl group; the radicals R3 to R8, which are identical or different, represent a hydrogen, an optionally substituted alkyl group or an optionally substituted aryl group; and X1 and X2, which are identical or different, are chosen from S, Se and O.

A method of quenching excited state energy from a photodegradable pigment that has been excited by absorption of light having a wavelength in the wavelength range of 290-800 nm, comprising reacting a pigment with a conjugated fused tricyclic compound having electron withdrawing groups of Formula (II) or a salt thereof: ##STR00001## wherein: A is selected from the group consisting of O, S, CO, CS, ##STR00002## B.sup.1, B.sup.2, D.sup.1 and D.sup.2 are each independently selected from the group consisting of F, Cl, Br, I, CF.sub.3, CC13, NR33+, NO2, CN, C(O)R4, C(O)OR, SO2R5, aryl, and CCHR6; each m independently is 0, 1, 2, 3, or 4; a is 0 or 1; each R is independently selected from the group consisting of LI, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, and aryl; R.sup.2 is selected from the group consisting of H, alkyl, cycloalkyl, alkenyl, alkynyl, and aryl; each R.sup.3 is independently selected from the group consisting of H and C.sub.1-C.sub.6 alkyl; each R.sup.4 is independently selected from the group consisting of H, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, and aryl; each R.sup.5 is independently selected from the group consisting of H, O, OH, NH.sub.2, and Cl; and each R.sup.6 is-independently selected from the group consisting of alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, and aryl.

The present invention relates to a method of visualizing biomolecules, having the steps of: a) providing a sample of immobilized biomolecules in a matrix and carry on the electrophoresis process; b) incubating the matrix of step a) in a solution containing a cyanine-derived molecule, for a time of 5 to 60 minutes, at room temperature, in a container preventing exposure to light, shaking the container at less of 75 rpm; c) transferring the matrix from step b) to a container with a solution having: at least one tetrazolium salt and incubating for a time of 15 to 120 minutes at room temperature under light exposure; d) removing the matrix with immobilized biomolecules from the previous step and washing with distilled water; and e) visualizing directly by the naked eye the biomolecules immobilized in the matrix.

The present invention relates to novel methine dyes, methods for the preparation thereof and use thereof for dyeing plastics, especially polyamides, so as to obtain yellow to orange colourings with improved light fastness and improved thermal stability.