scholarly journals Confined Monolayer Ice Between CaF2 (111) and Graphene: Structure and Stability

2021 ◽  
Vol 9 ◽  
Author(s):  
Shi-Qi Li ◽  
Shi Qiu ◽  
Hongsheng Liu ◽  
Maodu Chen ◽  
Junfeng Gao
Keyword(s):  
Small Deformation ◽  
Water Molecules ◽  
Confined Space ◽  
Structure And Stability ◽  
Modeling Systems ◽  
The Stability ◽  
Binding Energy Calculations ◽  
Bare Surface ◽  
Electronic Behavior ◽  
Confined System

Water monolayer can form in layered confined systems. Here, CaF2 (111) and graphene are chosen as modeling systems to explore the structure and stability of confined monolayer water. First, water molecules tend to intercalate into a confined space between graphene and CaF2, rather than on a bare surface of graphene. Water molecules can move fast in the confined space due to a low diffusion barrier. These water molecules are likely to aggregate together, forming monolayer ice. Four ice phases including ice II, ice III, ice IV, and ice Ih are compared in this confined system. Intriguingly, all the ice phases undergo very small deformation, indicating the 2D monolayer ice can be stable in the CaF2–graphene–confined system. Beyond, projected band structures are also plotted to understand the electronic behavior of these confined ice phases. Nearly all the bands originated from confined ices are flat and locate about 2–3 eV below the Fermi level. Binding energy calculations suggest that the stability sequence in this confined system as follows: Ih-up ≈ Ih-down ≈ II < IV < III. Our results bring new insights into the formation of water monolayer production in such a confined condition.

The effect of hydration on the electronic structure and stability of the superalkali cation Li3+

2018 ◽  
Vol 20 (22) ◽  
pp. 15174-15182 ◽  
Author(s):  
Jia-Huan Hou ◽  
Di Wu ◽  
Jia-Yuan Liu ◽  
Si-Yi Li ◽  
Dan Yu ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Water Molecules ◽  
Structure And Stability ◽  
The Stability

Insights into the interaction between the superalkali cation Li3+ and water molecules and the stability of the resulting hydrates.

scholarly journals Synthesis and Complexation Properties of 2-Hydroxy-5-methoxyphenylphosphonic Acid (H3L1). Crystal Structure of the [Cu(H2L1)2(Н2О)2] Complex

2021 ◽  
Vol 91 (11) ◽  
pp. 2176-2186
Author(s):  
G. S. Tsebrikova ◽  
Yu. I. Rogacheva ◽  
I. S. Ivanova ◽  
A. B. Ilyukhin ◽  
V. P. Soloviev ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Methoxy Group ◽  
Protonation Constants ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Stability ◽  
Intramolecular Hydrogen ◽  
Oxygen Atoms

Abstract 2-Hydroxy-5-methoxyphenylphosphonic acid (H3L1) and the complex [Cu(H2L1)2(H2O)2] were synthesized and characterized by IR spectroscopy, thermogravimetry, and X-ray diffraction analysis. The polyhedron of the copper atom is an axially elongated square bipyramid with oxygen atoms of phenolic and of monodeprotonated phosphonic groups at the base and oxygen atoms of water molecules at the vertices. The protonation constants of the H3L1 acid and the stability constants of its Cu2+ complexes in water were determined by potentiometric titration. The protonation constants of the acid in water are significantly influenced by the intramolecular hydrogen bond and the methoxy group. The H3L1 acid forms complexes CuL‒ and CuL24‒ with Cu2+ in water.

Theoretical study of electron structure and stability of quasiaromatic analogues of azulene

1981 ◽  
Vol 46 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Pavol Zahradník ◽  
Elena Ďurčíková ◽  
Jaroslav Leška
Keyword(s):  
Hydrogen Bond ◽  
Interaction Energy ◽  
Theoretical Study ◽  
Electron System ◽  
Stabilization Energy ◽  
Strong Hydrogen Bond ◽  
Hydrogen Bridge ◽  
Structure And Stability ◽  
Energy Interaction ◽  
The Stability

Semiempirical CNDO/2 method was used in the study of 23 quasiaromatic azulene analogues containing a hydrogen bridge A..H-D, where A and D denote O, NH, or S. The values of the stabilization energy, interaction energy, and changes of Wiberg's indexes suggest that the stability of the studied compounds is caused by a strong hydrogen bond as well as by a strong delocalization of the π-electron system. Derivatives in which A and D are O and NH are especially stable. Derivatives containing an oxo or thio group are preferred in tautomeric equilibriums.

scholarly journals Capacitive Sensing of Icing under Vacuum and Cryogenic Temperatures

Sensors ◽  
2019 ◽  
Vol 19 (16) ◽  
pp. 3574 ◽  
Author(s):  
Juliana Padilha Leitzke ◽  
Tobias Mitterer ◽  
Hubert Zangl
Keyword(s):  
Capacitive Sensor ◽  
Water Molecules ◽  
Residual Water ◽  
Cryogenic Temperatures ◽  
Term Study ◽  
Long Term Study ◽  
Cryogenic Liquids ◽  
Sensor Configuration ◽  
The Stability

In certain industrial processes, ice aggregations on surfaces can occur under almost vacuum conditions and at very low to cryogenic temperatures due to residual water molecules. This aggregation can affect the performance of the process and it is therefore of interest to monitor such surfaces. In this paper, we present a capacitive ice measurement system capable to operate in vacuum and temperatures of about - 120 ∘ C and below. We present a capacitive sensor setup with a separation of sensor element and sensor electronics, such that the sensor electronics can reside outside the cold environment. It is demonstrated that the permittivity of such ice formations at vacuum and low temperatures is sufficient for measurement using the proposed sensor configuration. Results from a long-term study using a prototype further demonstrate the stability of the system and thus the feasibility of the proposed system for long term condition monitoring of surfaces in vacuum that are e.g., cooled by cryogenic liquids. The developed system uses wireless communication in order to allow for simple retrofitting of existing infrastructure even in remote locations.

A three-dimensional polycatenation framework:catena-poly[[diaquabis(4-{4-[4-(pyridin-4-yl)phenoxy]phenyl}pyridine)nickel(II)]-μ2-naphthalene-2,6-dicarboxylato]

2013 ◽  
Vol 69 (9) ◽  
pp. 1022-1025 ◽  
Author(s):  
Cui-Lian Guo ◽  
Xiao-Qiang Yao ◽  
Yong-Qiang Cheng ◽  
Yan Liu
Keyword(s):  
Three Dimensional ◽  
Water Molecules ◽  
Intermolecular Hydrogen Bonds ◽  
One Dimensional ◽  
Pyridine Ligands ◽  
Carboxylate Groups ◽  
Distorted Octahedral ◽  
Benzene Rings ◽  
The Stability ◽  
Coordinated Water

In the title compound, [Ni(C12H6O4)(C22H16N2O)2(H2O)2]n, the Ni2+cation resides on a centre of inversion in a slightly distorted octahedral [N2O4] environment. The two carboxylate groups of each naphthalene-2,6-dicarboxylate (NDC2−) ligand, which reside on centres of inversion, link the NiIIcations into a one-dimensional chain. Identical chains are linked by intermolecular hydrogen bonds between coordinated water molecules and the uncoordinated N atoms of 4-{4-[4-(pyridin-4-yl)phenoxy]phenyl}pyridine ligands to form (4,4)-topological sheets, and then the different sheets are interlocked in an inclined fashion to give a three-dimensional polycatenation network. The stability of the structure is further enhanced by π–π stacking interactions between pyridine and benzene rings.

Mechanistic Information on the Aquations of Complexes of the Pentaamminecobalt(III) Series from Kinetic Studies at High Pressures

1972 ◽  
Vol 50 (17) ◽  
pp. 2739-2746 ◽  
Author(s):  
W. E. Jones ◽  
L. R. Carey ◽  
T. W. Swaddle
Keyword(s):  
High Pressures ◽  
Rate Coefficient ◽  
Kinetic Studies ◽  
Quadratic Equation ◽  
Water Molecules ◽  
First Order ◽  
Unit Slope ◽  
Straight Line ◽  
The Mean ◽  
The Stability

The logarithm of the pseudo-first-order rate coefficient k for the aquation of Co(NH3)5X(3–n)+ can be represented by a quadratic equation in the pressure P, or, better, by[Formula: see text]where P is in kbar, [Formula: see text] is the volume of activation at P = 0, and x is the increase in the number of water molecules solvating the complex as it goes to the transition state. For [Formula: see text]Cl−, Br−,[Formula: see text] and [Formula: see text] at 25° [Formula: see text] and ionic strength I = 0.1 M LiClO4/HClO4, [Formula: see text] −10.6, −9.2, −6.3, and +16.8 cm3 mol−1, and x = 8.0, 4.1, 3.9, 1.9, and −4.2; for Xn− = NCS−, the mean ΔV* from P = 0.001 to 2.5 kbar at 88° is −4 cm3 mol−1. Detailed consideration of these data, especially their correlation with the molar volume of reaction by a straight line of unit slope for [Formula: see text] Cl−, Br−, NO3−, and H2O, provides strong evidence for a dissociative interchange mechanism. For [Formula: see text] the separating entity is probably HN3 rather than [Formula: see text] For Xn− = NCS−, aquation is incomplete, at practical complex concentrations; at 88.0°, 1 bar, and I = 0.1 M LiClO4/HClO4, k = 3.3 × 10−6 s−1 and the stability constant of Co(NH3)5NCS2+ is 490 M−1.

scholarly journals Water Molecules in the Carbon C60 Confined Space

2018 ◽  
Vol 09 (02) ◽  
pp. 15-21
Author(s):  
M. Baskar ◽  
N. Sathyan ◽  
T. R. Gopalakrishnan Nair
Keyword(s):  
Water Molecules ◽  
Confined Space

The Rate of Evaporation of Water through Duplex Films

1948 ◽  
Vol 1 (2) ◽  
pp. 197 ◽  
Author(s):  
AR Gilby ◽  
E Heymann
Keyword(s):  
Atmospheric Pressure ◽  
Interfacial Layer ◽  
Water Surface ◽  
Complex Nature ◽  
Water Molecules ◽  
Total Evaporation ◽  
Film Evaporation ◽  
Wind Velocities ◽  
Rate Of Evaporation ◽  
The Stability

The stability of duplex films of hydrocarbon oils containing spreaders is discussed in this paper. Duplex films containing spreaders of high molecular weight and of complex nature, e.g. stand oil, eucalyptus residue, polymerized oleic acid, may remain spread for long periods but are thermodynamically metastable. The penetration of water molecules from a water surface through a duplex film has been discussed in terms of the evaporation resistances of the interfacial layer of spreader, the bulk layer of oil and the stagnant layer of air above the film. Evaporation through duplex films of thickness 1-100 μ has been studied in conditions of " still air " at atmospheric pressure and in a vacuum, and in non-turbulent winds at several controlled wind velocities. The efficiency of duplex films in reducing evaporation is greater in wind than in still air and Increases with the wind velocity. When duplex films thicker than 10 μ are placed on water surfaces, even a wind at 8 miles per hour does not increase the rate of evaporation. Thus with such films the resistance of the stagnant layer of air above the film is small compared with that of the oil layer and of the interfacial film of spreader. With all duplex films thicker than 10 μ the total evaporation resistance is proportional to the film thickness and depends on the nature of the spreader. An analysis of the experimental results suggests that the interfacial layer of spreader makes an appreciable contribution to the evaporation resistance of the duplex films under investigation. Approximate relative figures characterizing the magnitude of this contribution are calculated for several spreaders.

A DFT study on structure, stabilities and electronic properties of double magnesium doped gold clusters

RSC Advances ◽  
2014 ◽  
Vol 4 (100) ◽  
pp. 56571-56581 ◽  
Author(s):  
Debajyoti Bhattacharjee ◽  
Bhupesh Kr. Mishra ◽  
Ramesh Ch. Deka
Keyword(s):  
Binding Energy ◽  
Electronic Properties ◽  
Gold Clusters ◽  
Dft Study ◽  
Structure And Stability ◽  
Au Clusters ◽  
Doped Clusters ◽  
The Stability

The doping of two Mg atoms on Au-clusters has considerable effects on the structure and stability of gold clusters. The doped clusters enhance the stability of pure Au-clusters as observed from the binding energy plot.

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