Synthesis, Crystal Structure and Spectroscopic Studies of New Charge Transfer Compounds Obtained by Reaction of TTF and the Polyoxoanion [Mo6O19]2−

1989 ◽  
Vol 173 ◽  
Author(s):  
C. Bellitto ◽  
D. Attanasio ◽  
M. Bonamico ◽  
V. Fares ◽  
P. Imperatori ◽  
...  

ABSTRACTTwo different tetrathiafulvalene radical cation salts of the [M06O19]2−polyoxoanion have been isolated and characterized. Compound 1 corresponds to the chemical formula (TTF)3[Mo6019]. The crystal structure shows a ID stack of the donor TTF molecule, and each stack fits into channels formed by the anions. Within the stack a chain of trimers is identified, the inter-trimeric distance being 3.51 Å. The I.R., electronic and XPS spectra suggest the compound to be a mixed-valence salt. The electrical conductivity at room temperature is σ = 10−4Ω−1cm−1Compound 2 corresponds to the chemical+formula (TTF)2[M06019] . The compound consists of isolated (TTF+•)2dimers, interspersed with the polyoxoanions. In agreement with this crystal structure the compound is a diamagnetic insulator.

2012 ◽  
Vol 26 (32) ◽  
pp. 1250174 ◽  
Author(s):  
V. PRASHANTH KUMAR ◽  
Y. S. REDDY ◽  
P. KISTAIAH ◽  
C. VISHNUVARDHAN REDDY

The crystal structure at room temperature (RT), thermal expansion from RT to 1000°C and electrical conductivity, from RT to 600°C, of the perovskite-type oxides in the system Pr 1-x Sr x FeO 3(x = 0, 0.2, 0.4, 0.6) were studied. All the compounds have the orthorhombic perovskite GdFeO 3-type structure with space group Pbnm. The lattice parameters were determined by X-ray powder diffraction. The Pseudo cubic lattice parameter decreases with an increase in x, while the coefficient of linear thermal expansion increases. The thermal expansion is almost linear for x = 0 and 0.2. The electrical conductivity increases with increasing x while the activation energy decreases. The electrical conductivity can be described by the small polaron hopping conductivity model.


2015 ◽  
Vol 17 (21) ◽  
pp. 14107-14114 ◽  
Author(s):  
Wenzhi Yao ◽  
Steven P. Kelley ◽  
Robin D. Rogers ◽  
Thomas P. Vaid

Two mixed-valence room-temperature liquids are reported: BuFc–[BuFc+][NTf2−] (BuFc = n-butylferrocene) and TEMPO–[TEMPO+][NTf2−]. Both are conductors of DC electrical current, and their conductivity is modeled based on the electron-transfer self-exchange rate constants of their constituent redox-active species.


2013 ◽  
Vol 68 (4) ◽  
pp. 357-361 ◽  
Author(s):  
Di Sun ◽  
Shuai Yuan ◽  
Shan-Shan Liu ◽  
Ya-Qin Zhao ◽  
Lu-Lu Han ◽  
...  

The ultrasound-assisted reaction of AgNO3, 2-amino-4,6-dimethylpyrimidine (dmapym) and 2,6-naphthalenedicarboxylic acid (H2npd) gave rise to a new 2D network of the formula [Ag2(dmapym)2(npd)]n (1). The atoms Ag1 and Ag2 in the complex show seesaw and distorted tetrahedral coordination geometries, respectively. The dmapym ligand acts as a bidentate bridge to bind paired Ag(I) ions into a chain. The chains are further connected by npd linkers to form the resultant 2D network reinforced by N-H···O hydrogen bonds between dmapym and npd. Weak C-H···p interactions are also found in the crystal structure. Complex 1 exhibits photoluminescence in the solid state at room temperature with an emission maximum at 418 nm upon excitation at 330 nm.


2020 ◽  
Vol 49 (39) ◽  
pp. 13737-13743
Author(s):  
Mariana F. G. Velho ◽  
Rafaela A. L. Silva ◽  
Graça Brotas ◽  
Elsa B. Lopes ◽  
Isabel C. Santos ◽  
...  

A gold bisdithiolene complex with a unique crystal structure displays high electrical conductivity at room temperature.


1987 ◽  
Vol 41 (8) ◽  
pp. 1377-1382 ◽  
Author(s):  
John R. Ferraro ◽  
Hau H. Wang ◽  
John Ryan ◽  
Jack M. Williams

A series of infrared reflectance measurements using FT-IR Micro methods were conducted on bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF or “ET”) and bis(propylenedithio)tetrathiafulvalene (BPDT or “PT”) salts of the type (ET)2 X, where X = I3, AuCl2−, AuBr2−, AuI2−, I2Br−, IBr2, ICl2, ReO4−, ClO4−, and [Formula: see text]; and (PT)2 X, where X = I3−, IBr2−, I2Br−, and ICl2−. The technique is useful for characterizing, at room temperature, differences between β-, β′- and α′-type structures vs. α-structures. The β-, β′-, and α′-type structures show a vibrational feature at ∼1280 cm−1 which has been assigned as the -C-C-H bending vibration and is absent in the spectrum of the α-type salts. This vibration shifts toward higher frequency in going from the PT to the ET salts, and the results indicate stronger hydrogen bonding and harder lattices in the ET salts as opposed to the PT salts. This frequency shift also appears to be a function of the electronegativity of the halogen in the anion moiety of the charge-transfer salt.


2021 ◽  
Vol 19 (3) ◽  
pp. 56-61
Author(s):  
Bilal Ahmed Omar ◽  
Rabab Shakour Ali

The ferritic nanocomposite which prepared has the chemical formula of (Co0.25𝑁𝑖0.25Zn0.5LaxFe2−xO4), for different values of (X= 0, 0. 25, 0. 5, 0. 75), by using the spontaneous combustion-gel method, where calcination had been at temperature of (700˚C) for two hours; then studied the structural properties of the resulting ferrite via X-Ray diffraction (XRD), and Scanning Electron Microscopy (SEM) The results denote that the ferrite has a unique phase with a spinal-shaped crystal structure and a granular size are (23-36) nm, with increase in lattice constant of decrease in porosity, and electrical properties were also take in to consideration, like value of dielectric constant, the loss coefficient also observed via increase the frequency. The alternating electrical conductivity (σa.c) increases with increasing frequency.


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