Group photophysical studies

Cardona CM, Alvarez J, Kaifer AE, McCarley TD, Pandey S, Baker GA, Bonzagni NJ, Bright FV (2000) Dendrimers functionalized with a single fluorescent dansyl group attached off center Synthesis and photophysical studies. J Am Chem Soc 122 6139-6144... 

The termination reaction of free radical polymerization is a typical example of an intermacromolecular diffusion controlled reaction.3 Photophysical studies carried out in the 1980 s demonstrated for the first time that the reaction is solvent- and molecular weight-dependent. The experiments involved triplet quenching of probes attached to polymer chain ends. A benzil group was linked to the end of one PS sample (PS-B) and an anthryl group was linked to the end of a second PS sample (PS-A). The quenching rate coefficient kq of the benzil phosphorescence by anthryl groups is given by Eq. (3.26), where r0 is the lifetime of benzil phosphorescence in the absence of anthryl and ris the benzil phosphorescence lifetime in the presence of anthryl in concentration [A],... 

A principal product formed by irradiating quinoline-2-carbonitrile (35) in acidified aqueous propan-2-ol has two quinoline rings linked through the 2-4 positions and has lost both cyano-groups. The mechanism put forward for this formal 1,2-addition reaction begins with electron transfer from propan-2-ol to an upper triplet state of protonated (35), followed by attack on a second (ground-state) molecule of (35). A photophysical study of the photoreduction of acridine... 

The photophysical studies of synthetic helical polypeptides have been extended to proteins that carry chromophoric groups at specific sites. One example is an avidin (a protein) that binds a pyrenylalanine-linked biotin (Py-Bi, X) [77],... 

Soluble, linear polymers analogous to 7.16, with Ru or Os coordinated to the bi-pyridyl center, have also been investigated in detail, and the electrochemical and photophysical studies performed support the existence of strong electronic interactions between the metal sites and the 7r-conjugated organic backbone [40]. Materials with terpyridyl groups bound to Ru have also been prepared by electrochemical polymerization [41]. 

---