Monocyclopentadienylhydride Derivatives of Ruthenium:  Stereoselective Proton Transfer and Proton-Hydride Exchange in an Extremely Short Dihydrogen Bond

2004 ◽  
Vol 126 (22) ◽  
pp. 7049-7062 ◽  
Author(s):  
Ester Cayuela ◽  
Félix A. Jalón ◽  
Blanca R. Manzano ◽  
Gustavo Espino ◽  
Walter Weissensteiner ◽  
...  
Keyword(s):  
Proton Transfer ◽  
Dihydrogen Bond ◽  
Derivatives Of

Ultrafast Measurements of Charge and Excited-State Intramolecular Proton Transfer in Solutions of 4‘-(N,N-Dimethylamino) Derivatives of 3-Hydroxyflavone

2004 ◽  
Vol 108 (34) ◽  
pp. 6938-6943 ◽  
Author(s):  
Simon Ameer-Beg ◽  
Stuart M. Ormson ◽  
Xavier Poteau ◽  
Robert G. Brown ◽  
Paolo Foggi ◽  
...  
Keyword(s):  
Excited State ◽  
Proton Transfer ◽  
Intramolecular Proton Transfer ◽  
Ultrafast Measurements ◽  
Derivatives Of

Single and double proton transfer in excited hydroxy derivatives of bipyridyl

1986 ◽  
Vol 35 (4) ◽  
pp. 189-197 ◽  
Author(s):  
Hanna Bulska ◽  
Anna Grabowska ◽  
Zbigniew R. Grabowski
Keyword(s):  
Proton Transfer ◽  
Double Proton Transfer ◽  
Derivatives Of

Excited-State Proton Transfer: Molecules in a Hurry to Get Rid of Antiaromaticity

2019 ◽  
Author(s):  
Chia-Hua Wu ◽  
Lucas Karas ◽  
Henrik Ottosson ◽  
Judy Wu
Keyword(s):  
Excited State ◽  
Proton Transfer ◽  
Chemical Shifts ◽  
Proton Relay ◽  
Proton Transfers ◽  
Bifunctional Compounds ◽  
Excited State Proton Transfer ◽  
Derivatives Of ◽  
Related Compounds

<p>Baird’s rule explains why and when excited-state proton transfer (ESPT) reactions happen in organic compounds. Bifunctional compounds that are [4<i>n</i>+2] π-aromatic in the ground state, become [4<i>n</i>+2] π-antiaromatic in the first <sup>1</sup>ππ* states, and proton transfer (either<i>inter-</i>or <i>intra-</i>molecularly) helps relieve excited-state antiaromaticity. Computed nucleus independent chemical shifts (NICS) for several ESPT examples (including excited-state intramolecular proton transfers (ESIPT), biprotonic transfers, dynamic catalyzed transfers, and proton relay transfers) document the important role of excited-state antiaromaticity. <i>o-</i>Salicylic acid undergoes ESPT only in the “antiaromatic” S<sub>1</sub>(<sup>1</sup>ππ*) state, but not in the “aromatic” S<sub>2</sub>(<sup>1</sup>ππ*) state. Stokes’ shifts of structurally-related compounds (<i>e.g.</i>, derivatives of 2-(2-hydroxyphenyl)benzoxazole and hydrogen-bonded complexes of 2-aminopyridine with pro tic substrates) vary depending on the antiaromaticity of the photoinduced tautomers. Remarkably, Baird’s rule predicts the effect of light on hydrogen bond strengths; hydrogen bonds that enhance (and reduce) excited-state antiaromaticity in compounds become weakened (and strengthened) upon photoexcitation.</p>

ChemInform Abstract: New Proton Transfer Lasing Systems-Derivatives of 2,2′-Bipyridyl: Synthesis and Photophysical Characteristics.

ChemInform ◽  
2010 ◽  
Vol 22 (43) ◽  
pp. no-no
Author(s):  
L. KACZMAREK ◽  
B. NOWAK ◽  
J. ZUKOWSKI ◽  
P. BOROWICZ ◽  
J. SEPIOL ◽  
...  
Keyword(s):  
Proton Transfer ◽  
Derivatives Of

New proton transfer lasing systems—derivatives of 2,2′-bipyridyl. Synthesis and photophysical characteristics

1991 ◽  
Vol 248 (1-2) ◽  
pp. 189-200 ◽  
Author(s):  
Ł. Kaczmarek ◽  
B. Nowak ◽  
J. Z̊ukowski ◽  
P. Borowicz ◽  
J. Sepiol ◽  
...  
Keyword(s):  
Proton Transfer ◽  
Derivatives Of

Phenyltetramethylguanidines: substituent effect on rates and isotope effects in their reaction with bis(4-nitrophenyl)cyanomethane in acetonitrile

1991 ◽  
Vol 69 (2) ◽  
pp. 205-210 ◽  
Author(s):  
Przemyslaw Pruszynski ◽  
Kenneth T. Leffek
Keyword(s):  
Proton Transfer ◽  
Transfer Reaction ◽  
Isotope Effects ◽  
Proton Transfer Reaction ◽  
Kinetic Isotope ◽  
Reaction Constant ◽  
Base Strength ◽  
Derivatives Of ◽  
Best Fit ◽  
Hammett Relationship

A series of 22 phenyl substituted derivatives of 2-phenyl-1,1′,3,3′-tetramethylguanidine were used as bases in the proton transfer reaction from bis(4-nitrophenyl)cyanomethane in acetonitrile solvent. Brønsted and Hammett type relationships are examined for this family of closely related substrates. The Brønsted relationship constructed from the pKa values determined in acetonitrile shows β = 0.55 ± 0.03. The best fit of the Hammett relationship, with special values for p-NO2 and p-CN groups, gives the reaction constant ρ = −1.39 ± 0.1. The kinetic isotope effect, kH/kD, increases from 9.6 to 12.4 at 25 °C with decreasing base strength, i.e., when the reaction becomes more thermoneutral. Key words: tetramethylguanidine, proton transfer, deuterium isotope effects.

scholarly journals Two pathways of proton transfer reaction to (triphos)Cu(η1-BH4) via a dihydrogen bond [triphos = 1,1,1-tris(diphenylphosphinomethyl)ethane]

2016 ◽  
Vol 45 (22) ◽  
pp. 9127-9135 ◽  
Author(s):  
I. E. Golub ◽  
O. A. Filippov ◽  
N. V. Belkova ◽  
L. M. Epstein ◽  
A. Rossin ◽  
...  
Keyword(s):  
Proton Transfer ◽  
Transfer Reaction ◽  
Proton Transfer Reaction ◽  
Dihydrogen Bond ◽  
Variable Strength

The interaction of alcohols of variable strength with the copper(i) borohydride complex (triphos)Cu(η1-BH4) results in a great variety of DHB complexes which encompass different mechanisms involving M–H and E–H bond (E = B, O) activation steps.

Sign in / Sign up

Export Citation Format

Share Document