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1
Nintendo eShop - Chromophore: The Two Brothers Director
Nintendo eShop - Chromophore: The Two Brothers Director's Cut E3 Trailer for Wii U
::2014/06/09::
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2
Pigments and Chromophores in Nature (3.7)
Pigments and Chromophores in Nature (3.7)
::2010/01/21::
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3
Chromophore-Chromophore Interactions (3.5)
Chromophore-Chromophore Interactions (3.5)
::2010/01/20::
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4
Chromophore, Chromophore Definition, Explanation of Chromophores
Chromophore, Chromophore Definition, Explanation of Chromophores
::2012/11/19::
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5
Chemistry of Colors
Chemistry of Colors
::2012/11/09::
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6
CGI Animated Audio-Visual Performance HD: "Chromophore" by - Paul Prudence
CGI Animated Audio-Visual Performance HD: "Chromophore" by - Paul Prudence
::2013/07/17::
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7
Synthesis of Polarity-Indicating Chromophore
Synthesis of Polarity-Indicating Chromophore
::2012/11/22::
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8
Chromophore Electro Plurality
Chromophore Electro Plurality
::2012/03/26::
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9
How to Pronounce Chromophore
How to Pronounce Chromophore
::2014/02/01::
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10
Chromophore [Red Nebula]
Chromophore [Red Nebula]
::2011/04/22::
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11
Chromophore: Color Blind Aid System DEMO
Chromophore: Color Blind Aid System DEMO
::2011/07/01::
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12
Happy Chromophore in Bacteriorhodopsin
Happy Chromophore in Bacteriorhodopsin
::2011/05/22::
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13
Chromophore [Blue Nebula]
Chromophore [Blue Nebula]
::2011/04/25::
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14
Chromophore
Chromophore
::2014/04/27::
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15
Chromophore [Imploding Star]
Chromophore [Imploding Star]
::2011/04/25::
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16
CHROMOPHORE
CHROMOPHORE
::2014/02/02::
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17
CHROMOPHORE
CHROMOPHORE
::2011/01/28::
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18
How to Pronounce Chromophores
How to Pronounce Chromophores
::2014/02/01::
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19
Molecular Chromophores for Next-Generation Solar Photon Harvesting, Andrew Ferguson - O+P 2013
Molecular Chromophores for Next-Generation Solar Photon Harvesting, Andrew Ferguson - O+P 2013
::2013/09/06::
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20
non-toxic enediyne-based antitumor antibiotics
non-toxic enediyne-based antitumor antibiotics
::2014/06/10::
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Auxochromes, Auxochromes Definition
Auxochromes, Auxochromes Definition
::2012/11/17::
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22
Paraiba tourmaline Blue and pink Brazil Batalha
Paraiba tourmaline Blue and pink Brazil Batalha
::2010/05/07::
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23
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IPL vs LASER Hair Removal
::2014/03/17::
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24
Intercalation into DNA studied by X-ray crystallography
Intercalation into DNA studied by X-ray crystallography
::2012/06/30::
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25
James & Michelle
James & Michelle
::2010/09/10::
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26
Human Eye: 04: Biochemistry
Human Eye: 04: Biochemistry
::2010/04/26::
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27
Argonaut larva with color-changing cells
Argonaut larva with color-changing cells
::2012/10/23::
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28
Two Brothers Official Trailer No.2
Two Brothers Official Trailer No.2
::2013/04/03::
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29
How to Pronounce Chromophoric
How to Pronounce Chromophoric
::2014/07/20::
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30
Laser Skin Whitening at ONLYAESTHETICS
Laser Skin Whitening at ONLYAESTHETICS
::2014/06/30::
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Freeman Dyson: The seminar series: convincing Oppenheimer
Freeman Dyson: The seminar series: convincing Oppenheimer
::2014/01/13::
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32
Color Radical Definition
Color Radical Definition
::2014/07/24::
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33
Alash Ensemble Track 3 (Tuvan Throat Singing) at the University of Chicago (Nov. 2013)
Alash Ensemble Track 3 (Tuvan Throat Singing) at the University of Chicago (Nov. 2013)
::2013/11/28::
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34
Aerosol Detector for any Nonvolatile or Semivolatile Analyte
Aerosol Detector for any Nonvolatile or Semivolatile Analyte
::2013/03/20::
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35
cen solar+spin 1920x1080
cen solar+spin 1920x1080
::2013/05/30::
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36
Alash Ensemble Track 1 (Tuvan Throat Singing) at the University of Chicago (Nov. 2013)
Alash Ensemble Track 1 (Tuvan Throat Singing) at the University of Chicago (Nov. 2013)
::2013/11/27::
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37
Alash Ensemble Track 6 (Tuvan Throat Singing) at the University of Chicago (Nov. 2013)
Alash Ensemble Track 6 (Tuvan Throat Singing) at the University of Chicago (Nov. 2013)
::2013/11/28::
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38
Alash Ensemble Track 2 (Tuvan Throat Singing) at the University of Chicago (Nov. 2013)
Alash Ensemble Track 2 (Tuvan Throat Singing) at the University of Chicago (Nov. 2013)
::2013/11/27::
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39
Enhanced Green Fluorescent Protein (EGFP) fly around.
Enhanced Green Fluorescent Protein (EGFP) fly around.
::2013/10/05::
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40
The ATGCAT hexamer binds racemic [Ru(phen)2dppz]2+
The ATGCAT hexamer binds racemic [Ru(phen)2dppz]2+
::2013/07/24::
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41
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Photofragmentation & Photoelimination Reactions
::2011/01/10::
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42
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Corona ultra RS Detector
::2012/04/11::
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43
The intercalation of daunomycin
The intercalation of daunomycin
::2012/06/29::
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44
GFP movie
GFP movie
::2011/03/21::
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45
Paraiba tourmaline from Batalha mine Brazil classic color
Paraiba tourmaline from Batalha mine Brazil classic color
::2010/04/28::
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46
We Are From The Future
We Are From The Future
::2014/06/16::
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47
20. Electronic and Vibrational Spectroscopy
20. Electronic and Vibrational Spectroscopy
::2012/04/05::
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48
Paraiba tourmaline from Brazil.  Not tested and unsure if cuprian or not.
Paraiba tourmaline from Brazil. Not tested and unsure if cuprian or not.
::2010/05/01::
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49
Cobalt bearing spinel
Cobalt bearing spinel
::2010/05/14::
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New Technology to Control the Dispersion of Single-Wall CNT with Light
New Technology to Control the Dispersion of Single-Wall CNT with Light
::2011/09/07::
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From Wikipedia, the free encyclopedia
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A chromophore is the part of a molecule responsible for its color.[1] The color arises when a molecule absorbs certain wavelengths of visible light and transmits or reflects others. The chromophore is a region in the molecule where the energy difference between two different molecular orbitals falls within the range of the visible spectrum. Visible light that hits the chromophore can thus be absorbed by exciting an electron from its ground state into an excited state.

In biological molecules that serve to capture or detect light energy, the chromophore is the moiety that causes a conformational change of the molecule when hit by light.

Chemical structure of beta-carotene. The eleven conjugated double bonds that form the chromophore of the molecule are highlighted in red.

Conjugated pi-bond system chromophores[edit]

Conjugated chromophore that straightens in response to a photon γ (light), of the correct wavelength: 11-cis-retinal becomes all-trans-retinal

In the conjugated chromophores, the electrons jump between energy levels that are extended pi orbitals, created by a series of alternating single and double bonds, often in aromatic systems. Common examples include retinal (used in the eye to detect light), various food colorings, fabric dyes (azo compounds), pH indicators, lycopene, β-carotene, and anthocyanins. Various factors in a chromophore's structure go into determining at what wavelength region in a spectrum the chromophore will absorb. Lengthening or extending a conjugated system with more unsaturated (multiple) bonds in a molecule will tend to shift absorption to longer wavelengths. Woodward-Fieser rules can be used to approximate ultraviolet-visible maximum absorption wavelength in organic compounds with conjugated pi-bond systems.

Some of these are metal complex chromophores, which contain a metal in a coordination complex with ligands. Examples are chlorophyll, which is used by plants for photosynthesis and hemoglobin, the oxygen transporter in the blood of vertebrate animals. In these two examples, a metal is complexed at the center of a tetrapyrrole macrocycle ring: the metal being iron in the heme group (iron in a porphyrin ring) of hemoglobin, or magnesium complexed in a chlorin-type ring in the case of chlorophyll. The highly conjugated pi-bonding system of the macrocycle ring absorbs visible light. The nature of the central metal can also influence the absorption spectrum of the metal-macrocycle complex or properties such as excited state lifetime.[2][3][4] The tetrapyrrole moiety in organic compounds which is not macrocyclic but still has a conjugated pi-bond system still acts as a chromophore. Examples of such compounds include bilirubin and urobilin, which exhibit a yellow color.

Auxochrome[edit]

An auxochrome is a functional group of atoms attached to the chromophore which modifies the ability of the chromophore to absorb light, altering the wavelength or intensity of the absorption.

Halochromism in chromophores[edit]

Halochromism occurs when a substance changes color as the pH changes. This is a property of pH indicators, whose molecular structure changes upon certain changes in the surrounding pH. This change in structure affects a chromophore in the pH indicator molecule. For example, phenolphthalein is a pH indicator whose structure changes as pH changes as shown in the following table:

Structure Phenolphthalein-low-pH-2D-skeletal.svg Phenolphthalein-mid-pH-2D-skeletal.svg
pH 0-8.2 8.2-12
Conditions acidic or near-neutral basic
Color name
colorless
pink to fuchsia
Color

In a pH range of about 0-8, the molecule has three aromatic rings all bonded to a tetrahedral sp3 hybridized carbon atom in the middle which does not make the π-bonding in the aromatic rings conjugate. Because of their limited extent, the aromatic rings only absorb light in the ultraviolet region, and so the compound appears colorless in the 0-8 pH range. However as the pH increases beyond 8.2, that central carbon becomes part of a double bond becoming sp2 hybridized and leaving a p orbital to overlap with the π-bonding in the rings. This makes the three rings conjugate together to form an extended chromophore absorbing longer wavelength visible light to show a fuchsia color.[5] At pH ranges outside 0-12, other molecular structure changes result in other color changes; see Phenolphthalein for details.

See also[edit]

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