Acridinium 9-substituted

Me Capra in particular proposed n> that the chemiluminescence reactions of a large number of organic compounds had this concerted dioxetane decomposition step as key reaction in the production of electronically excited products, namely acridinium salts 25,26,27) indolylperoxides 28>, activated oxalic esters 29>, diphenyl carbene 30>, tetrakis-dimethylamino-ethylene 31 32>, lucigenin 33>, and substituted imidazoles 23>. 

When highly fluorescent ionic fluorophores, such as acridinium or xanthene dyes, are linked to a flexible electron-donor-substituted aryl group, a low-lying intramolecu-... 

Apocyanine dyes of the acridine series are obtained by treating acridinium iodide [43] or acridinium chloride [44] with tertiaiy aromatic amines. The dyes can also be obtained by ipso substitution of acridinium iodide with 4-haloaryl-amines in dimethyl sulfoxide at room temperature [45],... 

J. Lappe, R. J. Cave, M. D. Newton and I. V. Rostov, A theoretical investigation of charge transfer in several substituted acridinium ions, J. Phys. Chem. B, 109 (2005) 6610-6619. 

There is an interesting structural similarity between (66) and the other subjects of this section -(67) [149], (68) [150], (69) [151] and (70) [152,153] - in that they are all composed of 4-aminophenyl groups substituted at a meso position of a linearly fused tricyclic aromatic frame. The similarity continues even in their experimental behaviour in that protonation causes significant fluorescence enhancements in all cases. The structural elaboration of the aniline unit in (70) allows similar switching on with calcium ions. The case (70) is taken up further in Sect. 7. Additionally, (69) with its very electron deficient acridinium acceptor unit shows extensive perturbation of absorption spectra by several cations. Again, the acidity constants are experimentally identical in both the ground and excited singlet states. We close this final section of the survey... 

Table 22 Rate Constants for Reductive Coupling of A -Substituted Pyridinium, Quinolinium, and Acridinium Compounds...

An alternative approach to 9-substituted acridinium salts and thence the corresponding acridines involves the conversion of 9-acridones into the 9-trifluoromethanesulphonyloxy acridinium salts (17), which react readily with halides, pseudohalides such as azide and isothiocyanate, and sulphur nucleophiles (B. Singer and G. Maas, Z. Naturforsch., 1984, 39b, 1399). The free base restilts on reaction with diisopropyletlylamine. 9,9 -Bisacridine ethers are also available by this methodology. 

Quinoline 1-oxide can be substituted by mercaptans with the 3-isomer being the major product.Heterocyclic acid amides, such as lO-methyl-9-acridone and 2-methyl-l-phthala-zone, were aminoalkylated by ClMg(CHa)sNMe3. The carbinols formed have the character of pseudo bases and were transformed to the corresponding acridinium or phthalazinium salts. ... 

G15. Greyeski, M. L., Novak, T. J., and Mohan, A. G., Synthesis and comparison of substituted chemiluminescent acridinium derivatives including a novel acridinium amide. In Bioluminescence and Chemiluminescence Current Status (P. E. Stanley and L. J. Kricka, eds.), pp. 131-134. Wiley, Chichester, 1991. 

L2. Law, S.-J., Miller, T., Piran, U., Klukas, C., Chang, S., and Unger, J., Novel poly-substituted aryl acridinium esters and their use in immunoassay. J. Biotumin. Chemilumin. 4, 88-98... 

N. Chupakhin, and maintained first his candidate thesis Elucidation of the oxidative condensation of aromatic amines with acridinium salts (related to nucleophilic substitution of hydrogen)... 

Similar photosilylation reactions occur when one uses tri- and oligosilanes. Nakadaira and his co-workers reported the photosilylation of polycyano-aromatics and CFj-substituted benzenes. - Fukuzumi s group also has shown that acridinium ions are also sily-lated in photoreactions with hexamethyldisilane. - The photoreaction of hexamethyldisilane with quinones occurs to give silylated hydroquinones. ... 

Kinetics of the reduction of C-9 substituted acridinium cations by 1,4-dihydronicotinamides. Bioorg Chem 12 141-157... 

Another substrate for HRP is a stable trifluorophenyl substituted acridan known as Lumigen PS-3, which emits photons at 430 nm. The detection of HRP activity by PS-3 is based on a CL process involving the enzymatic generation of an intermediate acridinium ester. In the presence of hydrogen peroxide and p-iodophenol as enhancer, the action of the acridan substrate with the HRP label generates thousands of acridinium ester intermediates ([AE]- -) per minute, which react with hydrogen peroxide, at alkaline pH, to produce... 

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