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In spectroscopy, bathochromic shift (from Greek βαθύς (bathys) 'deep' and χρῶμα (chrōma) 'color'; hence less common alternate spelling "bathychromic") is a change of spectral band position in the absorption, reflectance, transmittance, or emission spectrum of a molecule to a longer wavelength (lower frequency). [1]
Negative solvatochromism corresponds to a hypsochromic shift (or blue shift) with increasing solvent polarity. An examples of negative solvatochromism is provided by 4-(4 ′-hydroxystyryl)-N-methylpyridinium iodide, which is red in 1-propanol, orange in methanol, and yellow in water.
An auxochrome is known as a functional group that produces a bathochromic shift, also known as red shift because it increases the wavelength of absorption, therefore moving closer to infrared light. Woodward−Fieser rules estimate the shift in wavelength of maximum absorption for several auxochromes attached to a conjugated system in an ...
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.
In spectroscopy, hypsochromic shift (from Ancient Greek ὕψος (upsos) 'height' and χρῶμα (chrōma) 'color') is a change of spectral band position in the absorption, reflectance, transmittance, or emission spectrum of a molecule to a shorter wavelength (higher frequency).
The logic gate operates as follows: without any chemical input of Ca 2+ or H +, the chromophore shows a maximum absorbance in UV/VIS spectroscopy at 390 nm. When calcium is introduced, a hypsochromic shift takes place and the absorbance at 390 nm decreases; likewise, an addition of protons causes a bathochromic shift . When both cations are in ...
1,1’-diethyl-2,2’-cyanine chloride (pseudoisocyanine chloride, PIC chloride) Fiber-like J-aggregates (yellow) and light-guiding microcrystallites (red) A J-aggregate is a type of dye with an absorption band that shifts to a longer wavelength (bathochromic shift) of increasing sharpness (higher absorption coefficient) when it aggregates under the influence of a solvent or additive or ...
With the aid of these rules the UV absorption maximum can be predicted, for example in these two compounds: [8] In the compound on the left, the base value is 214 nm (a heteroannular diene). This diene group has 4 alkyl substituents (labeled 1,2,3,4) and the double bond in one ring is exocyclic to the other (adding 5 nm for an exocyclic double ...