Sequential Proton Transfer Through Water Bridges in Acid-Base Reactions

Science ◽  
2005 ◽  
Vol 310 (5745) ◽  
pp. 83-86 ◽  
Author(s):  
O. F. Mohammed
Keyword(s):  
Proton Transfer ◽  
Acid Base ◽  
Water Bridges

scholarly journals SPECIFIC NATURE OF ACID-BASE INTERACTION OF OCTA(4-TERT-BUTYLPHENYL)TETRAPYRAZINOPORPHYRAZINE WITH ORGANIC PROTON-ACCEPTOR MOLECULES IN BENZENE

2021 ◽  
Vol 64 (3) ◽  
pp. 33-40
Author(s):  
Oleg A. Petrov ◽  
Aleksandr S. Semeykin ◽  
Mariya V. Shilovskaya ◽  
Tatiana V. Lyubimova
Keyword(s):  
Proton Transfer ◽  
Proton Acceptor ◽  
Base System ◽  
Excess Charge ◽  
Hydrogen Atoms ◽  
Acid Base ◽  
Base Interaction ◽  
Base Equilibrium ◽  
Acid Base Equilibrium ◽  
Acid Base Interaction

The reaction of acid-base interaction of octa(4-tert-butylphenyl)tetrapyrazinophosphyrazine with pyridine, 2-methylpyridine, morhpoline, pipyridine, n-butylamine, tert-butylamine, diethylamine, triethylamine and dimethylsulfoxide in benzene was investigated. It is shown that the researched porphyrazine forms kinetically stable proton transfer complexes with pyridine, 2-methylpyridine, morpholine and dimethylsulfoxide. In benzene-base system an acid-base equilibrium between the molecular form of octa(4-tert-butylphenyl)tetrapyrazinoporphyrazine and its proton transfer complex was established. The interaction of substituted tetrapyrazinoporphyrazine with morpholine in benzene was revealed to be a kinetically controllable process which occurs with low reaction rate and high values of activation energy. Such values are not inherent to most of relatively simple liquid-phase acid-base systems. The kinetic equation of the process was found, and, based on the spectral changes accompanying the reaction, a cheme of two-stage process of proton transfer of NH-groups of octa(4-tert-butylphenyl)tetrapyrazinoporphyrazine to morpholine in benzene was proposed. A possible structure of proton transfer complex of octa(4-tert-butylphenyl)tetrapyrazinoporphyrazine with organic bases is shown. In these complexes the inner hydrogen atoms of the cycle, bonded with base molecules, lie under and above the plane of the molecule, and the proton transfer from acid to base is limited either by the H-complex or the ion-ion associates constituting an H-bonded ion pair. Depending on the proton accepting tendency of the base, the acid-base equilibrium can shift towards or away from the more or less polarized structure. It was revealed that in benzene - n-butylamine (tri-butylamine, diethylamine, triethylamine, pipyridine) system the acid-base interaction involving octa(4- tert-butylphenyl)tetrapyrazinoporphyrazine occurs incredibly fast, with rates not measurable by standard spectrophotography methods. The forming proton transfer complexes are highly labile due to concurrent proton reaction occurring, leading to the formation of dianion form of octa(4- tert-butylphenyl)tetrapyrazinoporphyrazine. This form undergoes spontaneous dissolution into low-molecular colorless products due to the lack of compensation of excess charge in the macrocycle.

Electric field-driven acid-base transformation: proton transfer from acid(HBr/HF) to base(NH3/H2O)

2015 ◽  
Vol 31 (3) ◽  
pp. 418-426 ◽  
Author(s):  
Hailong Liang ◽  
Baojie Chai ◽  
Guanghui Chen ◽  
Wei Chen ◽  
Sheng Chen ◽  
...  
Keyword(s):  
Electric Field ◽  
Proton Transfer ◽  
Acid Base

Ultrafast Aqueous Bimolecular Acid-Base Proton Transfer: from Direct Exchange to Sequential Hopping

2007 ◽  
pp. 412-414 ◽  
Author(s):  
Omar F. Mohammed ◽  
Dina Pines ◽  
Jens Dreyer ◽  
Ehud Pines ◽  
Erik T. J. Nibbering
Keyword(s):  
Proton Transfer ◽  
Acid Base ◽  
Direct Exchange

Salt–cocrystal continuum for photofunction modulation: stimuli-responsive fluorescence color-tuning of pyridine-modified intramolecular charge-transfer dyes and acid complexes

2019 ◽  
Vol 7 (29) ◽  
pp. 8847-8854 ◽  
Author(s):  
Yoshio Yano ◽  
Toshikazu Ono ◽  
Sou Hatanaka ◽  
Daniel T. Gryko ◽  
Yoshio Hisaeda
Keyword(s):  
Charge Transfer ◽  
Proton Transfer ◽  
Intramolecular Charge Transfer ◽  
Stimuli Responsive ◽  
Photoluminescence Properties ◽  
Acid Base ◽  
Color Tuning ◽  
Crystalline Environment ◽  
Fluorescence Color

A series of acid–base complexes reveal ΔpKa value and the crystalline environment determine the extent of proton transfer, which governs the intramolecular charge-transfer (ICT) strength of the complexes and tunes the photoluminescence properties.

Investigations into an Intramolecular Proton Transfer and Solvent Dependent Acid‐Base Equilibria in 2,6‐Pyridine Diacetic Acid

2019 ◽  
Vol 4 (14) ◽  
pp. 4301-4307 ◽  
Author(s):  
Shivani Boodram ◽  
Soumyabrata Roy ◽  
Nadia Singh ◽  
Richard A. Fairman ◽  
Sebastian C. Peter ◽  
...  
Keyword(s):  
Proton Transfer ◽  
Intramolecular Proton Transfer ◽  
Diacetic Acid ◽  
Acid Base

Bifunctional proton transfer and acid-base properties of 1,4,7,10-tetraazacyclododecane (cyclen)

1977 ◽  
Vol 99 (11) ◽  
pp. 3794-3796 ◽  
Author(s):  
K. C. Chang ◽  
Ernest Grunwald ◽  
Lawrence R. Robinson
Keyword(s):  
Proton Transfer ◽  
Acid Base ◽  
Base Properties
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