The Interactions with Proton-Donor Solvents and Stability of some Borondipyrrinates

2015 ◽  
Vol 1088 ◽  
pp. 386-390
Author(s):  
Rimma T. Kuznetsova ◽  
Yulia V. Aksenova ◽  
Georgii V. Mayer ◽  
E.V. Antina
Keyword(s):  
Excited States ◽  
Spectroscopic Method ◽  
Proton Donor ◽  
Quantum Yields ◽  
Acid Base ◽  
Base Equilibrium ◽  
Spectral Shifts ◽  
Acid Base Equilibrium ◽  
Franck Condon

The constants of acid-base equilibrium were estimated with spectroscopic method at the ground (S0) and at the fluorescent (S1fl) states. The constants of acid-base equilibrium for Franck-Condon excited states (S1F-C) were estimated from spectral shifts for basic and acid forms. This results are compared with quantum yields of photostability of complexes in neutral solvents. The mechanisms of complexes protonation are discussed dependence from the structure of ligands.

Excited state acid–base equilibrium of tyrosine

1978 ◽  
Vol 56 (9) ◽  
pp. 1238-1245 ◽  
Author(s):  
David Michael Rayner ◽  
Donald Theodore Krajcarski ◽  
Arthur Gustav Szabo
Keyword(s):  
Excited State ◽  
Proton Transfer ◽  
Quantum Yields ◽  
Acid Base ◽  
Large Shift ◽  
Fluorescence Quantum Yields ◽  
Base Equilibrium ◽  
Tyrosine Fluorescence ◽  
Acid Base Equilibrium ◽  
Buffer Base

Fluorescence attributable to the tyrosinate form of the amino acid tyrosine, previously only observed at pH > pK(S0) = 10.3 where tyrosinate exists in the ground state, has been observed at neutral pH in the presence of high buffer base concentrations. This observation is consistent with the large shift in pK(Sl) predicted from absorption measurements and confirms that proton transfer is indeed a mechanism by which carboxylate ions quench tyrosine fluorescence. The dependence of the fluorescence quantum yields of tyrosine and tyrosinate on pH does not fit a simple excited state acid–base equilibrium model but a more complicated system where carboxylate is also capable of simultaneously quenching tyrosine fluorescence by a mechanism not involving proton transfer. Kinetic analysis of the system allows calculation of pK(S1) = 4.2 for tyrosine. The quantum yield of tyrosinate fluorescence can be appreciably higher than that normally measured at alkaline pH where a separate quenching mechanism must operate. These results have significance in the interpretation of the fluorescence properties of proteins.

scholarly journals ACID-BASE EQUILIBRIUM IN THE NORMAL

1942 ◽  
Vol 144 (2) ◽  
pp. 529-535
Author(s):  
Frank C. d'Elseaux ◽  
Frances C. Blackwood ◽  
Lucille E. Palmer ◽  
Katherine G. Sloman
Keyword(s):  
Acid Base ◽  
Base Equilibrium ◽  
Acid Base Equilibrium

scholarly journals THE ACID-BASE EQUILIBRIUM OF THE BLOOD IN PATHOLOGICAL CONDITIONS

1931 ◽  
Vol 90 (2) ◽  
pp. 607-617
Author(s):  
Edward Muntwyler ◽  
Natalie Limbach ◽  
Arthur H. Bill ◽  
Victor C. Myers
Keyword(s):  
Acid Base ◽  
Base Equilibrium ◽  
Pathological Conditions ◽  
Acid Base Equilibrium

scholarly journals TOTAL ACID-BASE EQUILIBRIUM OF PLASMA IN HEALTH AND DISEASE

1926 ◽  
Vol 67 (1) ◽  
pp. 175-218
Author(s):  
John P. Peters ◽  
Harold A. Bulger ◽  
Anna J. Eisenman ◽  
Carter Lee
Keyword(s):  
Acid Base ◽  
Total Acid ◽  
Base Equilibrium ◽  
Acid Base Equilibrium ◽  
Health And Disease

scholarly journals TOTAL ACID-BASE EQUILIBRIUM OF PLASMA IN HEALTH AND DISEASE

1926 ◽  
Vol 67 (1) ◽  
pp. 165-173 ◽  
Author(s):  
John P. Peters ◽  
Harold A. Bulger ◽  
Anna J. Eisenman
Keyword(s):  
Acid Base ◽  
Total Acid ◽  
Base Equilibrium ◽  
Acid Base Equilibrium ◽  
Health And Disease
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