The role of solvent reorganization dynamics in homogeneous electron self-exchange reactions

1987 ◽  
Vol 83 (1) ◽  
pp. 161 ◽  
Author(s):  
Günter Grampp ◽  
Wolfgang Harrer ◽  
Walther Jaenicke
Keyword(s):  
Exchange Reactions ◽  
Role Of Solvent

scholarly journals F/OH ratio in a rare fluorine-poor blue topaz from Padre Paraíso (Minas Gerais, Brazil) to unravel topaz’s ambient of formation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
N. Precisvalle ◽  
A. Martucci ◽  
L. Gigli ◽  
J. R. Plaisier ◽  
T. C. Hansen ◽  
...  
Keyword(s):  
Supercritical Fluids ◽  
Fluorine Content ◽  
Minas Gerais ◽  
Hydroxyl Groups ◽  
Exchange Reactions ◽  
Silicate System ◽  
Mullite Phase ◽  
Anomalous Water

AbstractTopaz [Al2SiO4(F,OH)2] is one of the main fluorine-bearing silicates occurring in environments where variably acidic (F)/aqueous (OH) fluids saturate the silicate system. In this work we fully characterized blue topaz from Padre Paraíso (Minas Gerais, Brazil) by means of in situ synchrotron X-Ray and neutron powder diffraction measurements (temperature range 298–1273 K) combined with EDS microanalyses. Understanding the role of OH/F substitution in topaz is important in order to determine the hydrophilicity and the exchange reactions of fluorine by hydroxyl groups, and ultimately to characterize the environmental redox conditions (H2O/F) required for mineral formation. The fluorine content estimated from neutron diffraction data is ~ 1.03 a.f.u (10.34 wt%), in agreement with the chemical data (on average 10.0 wt%). The XOH [OH/(OH + F)] (0.484) is close to the maximum XOH value (0.5), and represents the OH- richest topaz composition so far analysed in the Minas Gerais district. Topaz crystallinity and fluorine content sharply decrease at 1170 K, while mullite phase starts growing. On the basis of this behaviour, we suggest that this temperature may represent the potential initial topaz’s crystallization temperature from supercritical fluids in a pegmatite system. The log(fH2O/fHF)fluid (1.27 (0.06)) is coherent with the fluorine activity calculated for hydrothermal fluids (pegmatitic stage) in equilibrium with the forming mineral (log(fH2O/fHF)fluid = 1.2–6.5) and clearly different from pure magmatic (granitic) residual melts [log(fH2O/fHF)fluid < 1]. The modelled H2O saturated fluids with the F content not exceeding 1 wt% may represent an anomalous water-dominant / fluorine-poor pegmatite lens of the Padre Paraíso Pegmatite Field.

scholarly journals Dye-Surfactant Interaction: Role of Solvent

2013 ◽  
Vol 25 (18) ◽  
pp. 10499-10503 ◽  
Author(s):  
Ziya Ahmad Khan ◽  
Abdullah S. Al-Bogami
Keyword(s):  
Role Of Solvent

A first-principles study of the atomic layer deposition of ZnO on carboxyl functionalized carbon nanotubes: the role of water molecules

2021 ◽  
Vol 23 (5) ◽  
pp. 3467-3478
Author(s):  
J. I. Paez-Ornelas ◽  
H. N. Fernández-Escamilla ◽  
H. A. Borbón-Nuñez ◽  
H. Tiznado ◽  
Noboru Takeuchi ◽  
...  
Keyword(s):  
First Principles ◽  
Ligand Exchange ◽  
Functional Group ◽  
Atomic Layer ◽  
High Reactivity ◽  
Water Molecules ◽  
Exchange Reactions ◽  
Layer Deposition ◽  
The Right

Atomic description of ALD in systems that combine large surface area and high reactivity is key for selecting the right functional group to enhance the ligand-exchange reactions.

Role of Solvent in Excited-State Proton Transfer in Hypericin

1994 ◽  
Vol 98 (34) ◽  
pp. 8352-8358 ◽  
Author(s):  
F. Gai ◽  
M. J. Fehr ◽  
J. W. Petrich
Keyword(s):  
Excited State ◽  
Proton Transfer ◽  
Excited State Proton Transfer ◽  
Role Of Solvent

scholarly journals 155 The role of solvent mobility in protein dynamics

2015 ◽  
Vol 33 (sup1) ◽  
pp. 100-101
Author(s):  
Qiong Yang ◽  
Peng Sang ◽  
Shu-Qun Liu
Keyword(s):  
Protein Dynamics ◽  
Role Of Solvent

ChemInform Abstract: THE ROLE OF SOLVENT IN CONJUGATE ADDITIONS LEADING TO CIS- AND TRANS-1-ALKYL-2-ARYL-3-CARBO(AROYL)AZIRIDINES

1977 ◽  
Vol 8 (40) ◽  
pp. no-no
Author(s):  
P. TARBURTON ◽  
P. B. WOLLER ◽  
R. C. BADGER ◽  
E. DOOMES ◽  
N. H. CROMWELL
Keyword(s):  
Conjugate Additions ◽  
Cis And Trans ◽  
Role Of Solvent
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