Colored double complex

Antimony(III) chloride forms colored 7t-complexes with double bond systems (e.g. vitamin A). 

Antimony(V) chloride forms colored x-complexes with double bond systems. 45 — 50) and menihofuran (hR( 80— 85) yielded grey to brown chrumalugiam zones on a pale background, they fluoresced yellow under long-wavelength UV... 

Electrochemical detection of hybridization is mainly based on the differences in the electrochemical behavior of the labels with or without double-stranded (dsDNA) or single-stranded DNA (ssDNA). The labels for hybridization detection can be enzymes, anticancer agents, organic dyes, colorants, metal complexes, or metal nanoparticles among others. 

Thermal reaction. The charge-transfer absorption (or color) of the [R3MH, TCNE] complex fades in the dark, and a concomitant addition of the metal hydride to the TCNE double bond is observed188 (equation 50). 

Complex IV (cytochrome c oxidase) activity is measured by following at 550 nm (e 19,100-MAcnr1 isosbestic point 540 nm) the oxidation of cytochrome c (Fig. 3.8.5). It could be calculated as a first-order rate constant, or by estimating the pseudolinear initial rate of the reaction. Noticeably as a check, this initial rate should represent about double the rate measurable when 50% of the added cytochrome c has been oxidized (Fig. 3.8.5). Indeed, the affinity constant (Km) for reduced cytochrome c is about equivalent to the K, for oxidized cytochrome c. Reduced cytochrome c is easily prepared by adding a few crystals of dithionite to a solution of oxidized cytochrome c. After the immediate color change (from deep red to light orange-red), the solution should be carefully stirred to eliminate any trace of dithionite and should be totally odorless. 

These carotenoids have a limited distribution and occur as complexes, perhaps in Schiff base linkage, with proteins. Astaxanthin protein complexes with absorption maxima ranging from 410 nm to 625 nm or more provide the color to the lobster s exoskeleton.130132 Whereas most naturally occurring carotenoids have all-E double bonds, mono-Z isomers of canthaxanthin are found in the colored carotenopro-teins of the brine shrimp Artemesia.133... 

The system of conjugated double bonds responsible for carotenoid colors also helps to impart specific shapes to these largely hydrophobic molecules and ensures that they occupy the appropriate niches in the macromolecular complexes with which they associate. Information on stereochemistry is provided in a short review by Britton.138... 

In Sect. 2, a double network structure was proposed for the PVA films in the water-swollen state, i.e. an amorphous chain (tie chain) network and a fibrillar network. The blue color complex is considered to be formed mostly in the former network. Subsequently what happens in PVA films during soaking in aqueous solutions were discussed. The contractions of the volume and the long... 

A similar procedure applied to diethylenetriamine and dipropylenetriamine yielded only green hygroscopic solids which dissolved in alcohol with a green color, and in water to form brown solutions. They were insoluble in acetone and are presumably the following diaminecobalt (III) complexes as double salts with cobalt chloride ... 

Iodine interacts with many organic compounds to form pi complexes that are colored. This method of detection is especially useful for lipids containing double bonds. A lipid with several double bonds will give a darker spot with iodine. The darker spots may also be due to a higher concentration of lipid. 

Fig.. 1 The electroactive complex diffuses from ihc bulk electrolyte solution tA) through the diffusion layer (B) to the Helmholtz double layer (C) to be discharged as metallic chromium D on Hie cathode surface (Fj. After General Motors color sketch I...

The Cr1 ion readily forms complexes it exists in aqueous solution as CrfH 0)j. and forms other complexes wilh anions, such asCr(H 0).CI , Crother properties due to variation in the bonding. Compounds or the trichloride have been reported with the following arrangements CrtHjOlsClj. [CrfHiOlsCljCIi- HiO. and [Cr(HiO)4Cf CU2 H 0 Trivalenl chromium also forms double salts, notably the chromium alums, hydrated double salts of Cr(III) sulfate and the alkali metal (or thallium or ammonium) sulfates. 

Chemists have been combining small, simple hydrocarbon molecules into long-chain complex molecules for many years. The process is called polymerization, and the resulting product is called a plastic. When a simple, small hydrocarbon molecule like ethene (C2H4) is polymerized, polyethylene results =CH2=CH2= — CH3(CH2)n CH3. (Comment The two horizontal bars denote a double bond between the carbon atoms.) This is the product that is used to make transparent wrap, flexible bottles, and thousands of other products. In addition, polyethylene makes an outstanding macrosculpture material. It can be molded into an endless variety of interesting shapes. It can be colored or left clear. 

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