scholarly journals Anomalous thermal expansion in one-dimensional transition metal cyanides: Behavior of the trimetallic cyanide Cu1/3Ag1/3Au1/3CN

2019 ◽  
Vol 100 (17) ◽  
Author(s):  
Stella d’Ambrumenil ◽  
Mohamed Zbiri ◽  
Simon J. Hibble ◽  
Ann M. Chippindale ◽  
Dean S. Keeble ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Transition Metal ◽  
One Dimensional ◽  
Metal Cyanides ◽  
Anomalous Thermal Expansion

Synergistic effect of carbon nanotubes and graphitic carbon nitride on the enhanced supercapacitor performance of cobalt diselenide-based composites

2021 ◽  
Author(s):  
Mingjie Li ◽  
Xuan Zheng ◽  
Xiang Li ◽  
Youjun Yu ◽  
Jinlong Jiang
Keyword(s):  
Carbon Nanotubes ◽  
Transition Metal ◽  
Synergistic Effect ◽  
Hydrothermal Method ◽  
High Performance ◽  
Carbon Nitride ◽  
Electrode Materials ◽  
One Dimensional ◽  
Supercapacitor Performance ◽  
Metal Selenides

Recently, transition metal selenides have been investigated extensively as promising electrode materials for high-performance supercapacitors. Herein, the multi-component CoSe2/CNTs@g-C3N4 composites are prepared using a two-step hydrothermal method by incorporating one-dimensional...

Anomalous thermal expansion in ErFe11.4Nb0.6

2020 ◽  
Vol 823 ◽  
pp. 153649
Author(s):  
W.Q. Wang ◽  
F. Su ◽  
Y.F. Xue ◽  
Z.X. Cheng ◽  
Q.F. Gu ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Anomalous Thermal Expansion

Anomalous thermal expansion behaviors of wood under dry and low-temperature conditions

Holzforschung ◽  
2014 ◽  
Vol 68 (5) ◽  
pp. 567-574 ◽  
Author(s):  
Tsunehisa Miki ◽  
Hiroyuki Sugimoto ◽  
Yuzo Furuta ◽  
Ichinori Shigematsu ◽  
Kozo Kanayama
Keyword(s):  
Thermal Expansion ◽  
Linear Thermal Expansion ◽  
Longitudinal Direction ◽  
Mechanical Analysis ◽  
Solid Wood ◽  
Compression Pressure ◽  
Thermal Expansion Behavior ◽  
Expansion Behavior ◽  
Dry Conditions ◽  
Anomalous Thermal Expansion

Abstract The thermal expansion behavior of dry solid wood was investigated by dynamic dilatometry and thermal mechanical analysis. Anomalous thermal expansion behavior was observed concerning the displacement change under a constant compression pressure, which was not previously reported. Wood submitted to temperatures below 0°C under dry conditions exhibited a large increment in the linear thermal expansion coefficient (CLTE) and a sudden drop in the CLTE around 50°C as well as above 130°C during heating. In subsequent cooling/heating processes, these anomalous behaviors remained at temperatures below 100°C, although less pronounced, and disappeared at temperatures above 100°C. These behaviors were clearly perceptible in the radial and tangential directions but not in the longitudinal direction. The CLTE depended strongly on the heat and moisture history of the samples and the effects are species-specific.

Symmetry Violations in Partially Oxidized One-Dimensional (1D)Transition Metal Polymers. Metal-Ligand-Metal(M-L-M) Bridged Systems

1984 ◽  
Vol 39 (9) ◽  
pp. 807-829
Author(s):  
Michael C. Böhm
Keyword(s):  
Transition Metal ◽  
Density Wave ◽  
Tight Binding ◽  
Mean Field ◽  
Valence Bond ◽  
Hole State ◽  
One Dimensional ◽  
Metal Derivatives ◽  
A Charge ◽  
Metal Ligand

The band structure of the metal-ligand-metal (M-L-M) bridged quasi one-dimensional (1D) cyclopentadienylmanganese polymer, MnCp 1, has been studied in the unoxidized state and in a partly oxidized modification with one electron removed from each second MnCp fragment. The tight-binding approach is based on a semiempirical self-consistent-field (SCF) Hartree-Fock (HF) crystal orbital (CO) model of the INDO-type (intermediate neglect of differential overlap) combined with a statistical averaging procedure which has its origin in the grand canonical ensemble. The latter approximation allows for an efficient investigation of violations of the translation symmetries in the oxidized 1D material. The oxidation process in 1 is both ligand- and metal-centered (Mn 3d-2 states). The mean-field minimum corresponds to a charge density wave (CDW) solution with inequivalent Mn sites within the employed repeat-units. The symmetry adapted solution with electronically identical 3d centers is a maximum in the variational space. The coupling of this electronic instability to geometrical deformations is also analyzed. The ligand amplitudes encountered in the hole-state wave function prevent extremely large charge separations between the 3d centers which are found in ID systems without bridging moieties (e.g. Ni(CN)2-5 chain). The symmetry reduction in oxidized 1 is compared with violations of spatial symmetries in finite transition metal derivatives and simple solids. The stabilization of the valence bond-type (VB) solution is physically rationalized (i.e. left-right correlations between the 3d centers). The computational results derived for 1 are generalized to oxidized transition metal chains with band occupancies that are simple fractions of the number of stacking units and to 1D systems that deviate from this relation. The entropy-influence for temperatures T ≠ 0 is shortly discussed (stabilization of domain or cluster structures).

Carbon-13/carbon-12 isotope effects on nitrogen-15 chemical shielding in some diamagnetic cyano complexes

1982 ◽  
Vol 60 (17) ◽  
pp. 2194-2197 ◽  
Author(s):  
Roderick E. Wasylishen
Keyword(s):  
Transition Metal ◽  
High Field ◽  
Chemical Shifts ◽  
Isotope Effects ◽  
Chemical Shielding ◽  
Cyanide Ion ◽  
Theoretical Formulation ◽  
Metal Cyanides ◽  
Shielding Constants ◽  
Cyano Complexes

Carbon-13/carbon-12 isotope-induced 15N chemical shifts of 0.06 to 0.10 ppm have been observed for the cyanide ion and several transition metal cyanides. In each case, the 15N resonance of the 13C labelled isotopomers is to high field of that in the corresponding carbon-12 species. The sensitivity of the 15N and 13C shielding constants in the cyanide ion to small changes in the CN bond length are evaluated using the theoretical formulation of Jameson: (∂σ(15N)/∂r)e = −872 ± 160 ppm/Å and (∂σ(13C)/∂r)e = −473 ± 90 ppm/Å. Nitrogen-15 chemical shifts in the metal complexes exhibit basically the same behaviour as do the 13C chemical shifts in these same complexes.

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