scholarly journals Hydration of Nucleobase as Probed by Electron Emission of Uridine-5′-Mono-Phosphate (UMP) in Aqueous Solution Induced by Nitrogen K-Shell Ionization

2020 ◽  
Vol 4 (1) ◽  
pp. 10
Author(s):  
Yasuaki Takeda ◽  
Hiroyuki Shimada ◽  
Ryosuke Miura ◽  
Masatoshi Ukai ◽  
Kentaro Fujii ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Dna Lesions ◽  
Photoelectron Spectra ◽  
Water Molecules ◽  
Orbital Electron ◽  
Radiation Processes ◽  
Early Radiation ◽  
Auger Effect ◽  
Shell Ionization ◽  
Auger Electron Spectra

To identify the precise early radiation processes of DNA lesions, we measure electron kinetic energy spectra emitted from uridine-5′ monophosphate (UMP) in aqueous solution for the photoionization of the N 1s orbital electron and for the following Auger effect using a monochromatic soft X-ray synchrotron radiation at energies above the nitrogen K-shell ionization threshold. The change of photoelectron spectra for UMP in aqueous solutions at different proton concentrations (pH = 7.5 and 11.3) is ascribed to the chemical shift of the N3 nitrogen atom in uracil moiety of canonical and deprotonated forms. The lowest double ionization potentials for aqueous UMP at different pH obtained from the Auger electron spectra following the N 1s photoionization values show the electrostatic aqueous interaction of uracil moiety of canonical (neutral) and deprotonated (negatively charged) forms with hydrated water molecules.

Structural Study of a new Compound Based on Acid 1,4-Cyclohexanedicarboxylic (1,4-CDC)

2010 ◽  
Vol 6 (1) ◽  
pp. 891-896
Author(s):  
Manel Halouani ◽  
M. Dammak ◽  
N. Audebrand ◽  
L. Ktari
Keyword(s):  
Aqueous Solution ◽  
Water Molecules ◽  
Carboxyl Group ◽  
X Ray Diffraction ◽  
Compound I ◽  
Unit Cell Parameters ◽  
Monoclinic System ◽  
X Ray ◽  
Cell Parameters ◽  
Cyclohexanedicarboxylic Acid

One nickel 1,4-cyclohexanedicarboxylate coordination polymers, Ni2 [(O10C6H4)(COO)2].2H2O  (I), was hydrothermally synthesized from an aqueous solution of Ni (NO3)2.6H2O, (1,4-CDC) (1,4-CDC = 1,4-cyclohexanedicarboxylic acid) and tetramethylammonium nitrate. Compound (I) crystallizes in the monoclinic system with the C2/m space group. The unit cell parameters are a = 20.1160 (16) Å, b = 9.9387 (10) Å, c = 6.3672 (6) Å, β = 97.007 (3) (°), V= 1263.5 (2) (Å3) and Dx= 1.751g/cm3. The refinement converged into R= 0.036 and RW = 0.092. The structure, determined by single crystal X-ray diffraction, consists of two nickel atoms Ni (1) and Ni (2). Lots of ways of which is surrounded by six oxygen atoms, a carboxyl group and two water molecules.

scholarly journals Crystal structure of the new hybrid material bis(1,4-diazoniabicyclo[2.2.2]octane) di-μ-chlorido-bis[tetrachloridobismuthate(III)] dihydrate

2015 ◽  
Vol 71 (11) ◽  
pp. 1384-1387
Author(s):  
Marwen Chouri ◽  
Habib Boughzala
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Hydrogen Bonds ◽  
Room Temperature ◽  
Molar Ratio ◽  
Water Molecules ◽  
Site Symmetry ◽  
Two Dimensional ◽  
Slow Evaporation ◽  
Solution Ph

The title compound bis(1,4-diazoniabicyclo[2.2.2]octane) di-μ-chlorido-bis[tetrachloridobismuthate(III)] dihydrate, (C6H14N2)2[Bi2Cl10]·2H2O, was obtained by slow evaporation at room temperature of a hydrochloric aqueous solution (pH = 1) containing bismuth(III) nitrate and 1,4-diazabicyclo[2.2.2]octane (DABCO) in a 1:2 molar ratio. The structure displays a two-dimensional arrangement parallel to (100) of isolated [Bi2Cl10]4−bioctahedra (site symmetry -1) separated by layers of organic 1,4-diazoniabicyclo[2.2.2]octane dications [(DABCOH2)2+] and water molecules. O—H...Cl, N—H...O and N—H...Cl hydrogen bonds lead to additional cohesion of the structure.

scholarly journals Removal of Chromium from Aqueous Solution Using Modified Pomegranate Peel:Mechanistic and Thermodynamic Studies

2009 ◽  
Vol 6 (s1) ◽  
pp. S153-S158 ◽  
Author(s):  
Tariq S. Najim ◽  
Suhad A. Yassin
Keyword(s):  
Activation Energy ◽  
Solid Solution ◽  
Aqueous Solution ◽  
Adsorption Process ◽  
Batch Process ◽  
The Other ◽  
Water Molecules ◽  
Pomegranate Peel ◽  
Solution Interface ◽  
Adsorbent Surface

Modified pomegranate peel (MPGP) and formaldehyde modified pomegranate peel (FMPGP) were prepared and used as adsorbent for removal of Cr(VI) ions from aqueous solution using batch process. The temperature variation study of adsorption on both adsorbents revealed that the adsorption process is endothermic, from the positive values of ∆H˚. These values lie in the range of physisorption. The negative values of ∆G˚ show the adsorption is favorable and spontaneous. On the other hand, these negative values increases with increase in temperature on both adsorbents, which indicate that the adsorption is preferable at higher temperatures. ∆S˚ values showed that the process is accompanied by increase in disorder and randomness at the solid solution interface due to the reorientation of water molecules and Cr(VI) ions around the adsorbent surface. The endothermic nature of the adsorption was also confirmed from the positive values of activation energy, Ea, the low values of Ea confirm the physisorption mechanism of adsorption. The sticking probability, S*, of Cr(VI) ion on surface of both adsorbents showed that the adsorption is preferable due to low values of S*(0< S*< 1 ), but S*values are lower for FMPGP indicating that the adsorption on FMPGP is more preferable .

scholarly journals Structure and hydrogen bonding of the hydrated selenite and selenate ions in aqueous solution

2014 ◽  
Vol 43 (17) ◽  
pp. 6315-6321 ◽  
Author(s):  
Lars Eklund ◽  
Ingmar Persson
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Bonding ◽  
Free Electron ◽  
Electron Pair ◽  
Bound Water ◽  
Water Molecules ◽  
Hydration Sphere ◽  
Free Electron Pair

The selenite ion has an asymmetric hydration sphere with loosely electrostatically bound water molecules outside the free electron pair.

scholarly journals Dynamics of Water Molecules in Concentrated Aqueous Solution of D-Glucose

2013 ◽  
Vol 25 (14) ◽  
pp. 8225-8226 ◽  
Author(s):  
Yong-Qiang Chen ◽  
Xiao-Ming Yang
Keyword(s):  
Aqueous Solution ◽  
Water Molecules

scholarly journals Supramolecular Complexes of Cucurbiturils with Second Group Metal Salts and Hydrates and Histamine

INEOS OPEN ◽  
2021 ◽  
Vol 4 ◽  
Author(s):  
Yu. A. Borisov ◽  
◽  
S. S. Kiselev ◽  
Keyword(s):  
Aqueous Solution ◽  
Density Functional Theory ◽  
Density Functional ◽  
Metal Salts ◽  
Supramolecular Complexes ◽  
Water Molecules ◽  
Functional Theory ◽  
Guest Molecules ◽  
First Time ◽  
Formation Energies

The interaction of cucurbiturils (Q6, Q7, and Q8) with Ca and Ba chlorides and iodides are studied for the first time by density functional theory. The thermodynamic parameters for the formation of host–guest complexes are calculated. The structures of complexes of Q6 and Q7 with one and two guest molecules are established. The energy parameters for the transfer of Be2+ and Ba2+ cations from an aqueous solution into the cavity of Q7 containing n water molecules are defined. The dependences of the formation energies for complexes Q7WnBe2+ and Q7WnBa2+ on the number of water molecules are shown to be parabolic, with the energy minima at n = 5 and n = 6, respectively. It is found that Q7 can form in an aqueous solution supramolecular complexes with protonated histamine (HA) and neutral histamine in the presence of Ca2+ ions.

scholarly journals Computational Evidence Suggests That 1-chloroethanol May Be an Intermediate in the Thermal Decomposition of 2-chloroethanol into Acetaldehyde and HCl

2019 ◽  
Author(s):  
Zoi Salta ◽  
Agnie M. Kosmas ◽  
Oscar Ventura ◽  
Vincenzo Barone
Keyword(s):  
Aqueous Solution ◽  
Water Molecule ◽  
Gas Phase ◽  
Density Functional ◽  
Water Molecules ◽  
Functional Theory ◽  
Direct Transformation ◽  
The Density Functional Theory ◽  
Successive Step ◽  
The One

<p>The dehalogenation of 2-chloroethanol (2ClEtOH) in gas phase with and without participation of catalytic water molecules has been investigated using methods rooted into the density functional theory. The well-known HCl elimination leading to vinyl alcohol (VA) was compared to the alternative elimination route towards oxirane and shown to be kinetically and thermodynamically more favorable. However, the isomerization of VA to acetaldehyde in the gas phase, in the absence of water, was shown to be kinetically and thermodynamically less favorable than the recombination of VA and HCl to form the isomeric 1-chloroethanol (1ClEtOH) species. This species is more stable than 2ClEtOH by about 6 kcal mol<sup>-1</sup>, and the reaction barrier is 22 kcal mol<sup>-1</sup> vs 55 kcal mol<sup>-1</sup> for the direct transformation of VA to acetaldehyde. In a successive step, 1ClEtOH can decompose directly to acetaldehyde and HCl with a lower barrier (29 kcal mol<sup>-1</sup>) than that of VA to the same products (55 kcal mol<sup>-1</sup>). The calculations were repeated using a single ancillary water molecule (W) in the complexes 2ClEtOH_W and 1ClEtOH_W. The latter adduct is now more stable than 2ClEtOH_W by about 8 kcal mol<sup>-1</sup>, implying that the water molecule increased the already higher stability of 1ClEtOH in the gas phase. However, this catalytic water molecule lowers dramatically the barrier for the interconversion of VA to acetaldehyde (from 55 to 6 kcal mol<sup>-1</sup>). This barrier is now smaller than the one for the conversion to 1ClEtOH (which also decreases, but not so much, from 22 to 12 kcal mol<sup>-1</sup>). Thus, it is concluded that while 1ClEtOH may be a plausible intermediate in the gas phase dehalogenation of 2ClEtOH, it is unlikely that it plays a major role in water complexes (or, by inference, aqueous solution). It is also shown that neither in the gas phase nor in the cluster with one water molecule, the oxirane path is competitive with the VA alcohol path.</p>

Notizen: Pentaoxoiodate(VII)monoanion as an Intermediate in the Interconversion of Hexa- and Tetraoxoiodate(VII)monoanions in Aqueous Solution

1977 ◽  
Vol 32 (1) ◽  
pp. 114-115 ◽  
Author(s):  
G. J. Buist ◽  
C. J. Holloway
Keyword(s):  
Aqueous Solution ◽  
Crucial Role ◽  
Temperature Jump ◽  
Water Molecules ◽  
Definite Evidence ◽  
Relaxation Measurements

Results from temperature-jump relaxation measurements indicate the existence of an intermediate, the pentaoxoiodate(VII)monoanion, in the hydration-dehydration equilibrium between hexa- and tetraoxoiodate(VII)monoanions in aqueous solution. The interconversion is accompanied by a considerable reorientation of the water molecules solvating the monoanionic species, which play a crucial rôle in the mechanism of hydration and dehyd ation. This is the first definite evidence for the existence of a penta coordinated periodate species in aqueous solution.

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