Blue conjugated chains

Introduction of the acceptor squaraine and tetraone bridges to the conjugated chain causes BLA in the bridges resulting in a blue shift of the main absorption... 

By suitable substituents, used at the same time to increase the yield and facilitate processibility. Substitution usually shifts emission toward the red (see Table 4). However, the absorption and emission spectra of phenylPPV (PPPV), in which the phenyl is substituted to one of the H atoms on the phenyl ring in the conjugated chain, is blue-shifted by several hundred angstroms [292]. 

There have been several attempts to explain, with more or less rigour, the transmission of electronic effects into a double bond and down a conjugated chain, but none has yet settled in as the accepted way to picture what happens to the orbitals. In the most colourful approach, the electrostatic attraction of a point positive charge to the surface of a starting material is calculated, and then mapped onto the surface with a colour code—red for maximum attraction and blue for minimum attraction. The results are beautiful pictures showing red hot spots on the molecular surface, and they give an immediate and vivid sense of where electrophilic reagents are likely to attack.18... 

Copper Phthalocyanine. 6CgH C2N) Nj Cu solid d 1.59. A blue pigment deriv of org pigments having as a structural unit four isoindole groups, (CgH )C2N, linked by four N atoms so as to form a conjugated chain. It is extremely stable to Ugh acids, alkalies and heat. Can be prepd by reaction of phthalic anhydride, urea cuprous chloride at ca 200° or by reaction of o-chlorocyanobenzene with cuprous cyanide Cu pdr. Has been used in enamels, linoleum, plastics, rubber goods, etc. (Refs 2 3)-The uses of phthalocyanines in propints are discussed in Ref 4 Refs l)Beil - not found under Phthalcyanin or under 6 32 16 8 ° Hackh s (1944), 654 ... 

In lycopene, the chief colouring matter of the marigold, thirteen double bonds are present in the conjugated chain, A ax moves from the UV to the blue region of the visible spectrum and the colour seen is a reddish yellow. 

Ubiquitin/Proteasome. Figure 2 Functional consequences of ubiquitin linkage. Substrates (blue bars) are linked via lysine residues (K) to ubiquitin or ubiquitin chains, (a) Attachment of chains connected via Lysines in position 48 of ubiquitin (K48) targets substrates for proteasomal degradation. In contrast modification of one (b) or multiple (c) lysines by a single ubiquitin molecule mediates novel protein interactions or initiates endocytosis. Conjugation of K63-linked polyubiquitin (d) alters protein function and can also serve as a signal for endocytosis. 

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