Localization of vibrations near impurity atoms in semi-infinite and infinite linear chains

1999 ◽  
Vol 25 (8) ◽  
pp. 732-739 ◽  
Author(s):  
M. A. Mamalui ◽  
E. S. Syrkin ◽  
S. B. Fedosev
Keyword(s):  
Impurity Atoms ◽  
Linear Chains ◽  
Infinite Linear

Magnetic behaviour and structure of polymeric oxovanadium carboxylates

1972 ◽  
Vol 25 (6) ◽  
pp. 1195 ◽  
Author(s):  
AT Casey ◽  
BSSE Morris ◽  
JR Thackeray
Keyword(s):  
Molecular Structure ◽  
Magnetic Properties ◽  
Organic Acids ◽  
Electronic Spectra ◽  
Magnetic Behaviour ◽  
Antiferromagnetic Exchange ◽  
Broad Maximum ◽  
Linear Chains ◽  
Salts Of Organic Acids ◽  
Infinite Linear

The synthesis and properties of a series of oxovanadium(1V) carboxylates (i.e. salts of organic acids) are described. The complexes closely resemble each other in magnetic properties, the observed paramagnetism being abnormally low for oxo-vanadium(1V) in the temperature range 90-350 K, with a broad maximum around 200-250 K. After testing of all reasonable models, the magnetic properties are interpreted in terms of anisotropic (Ising) antiferromagnetic exchange along infinite linear chains of interacting spins. On the basis of this model and with the aid of infrared, e.s.r., and electronic spectra, the most probable molecular structure for the series of complexes can be given. In our interpretation of the evidence, the interactions are of the super-exchange type.

Modeling cooperative effects in halogen-bonded infinite linear chains

2017 ◽  
Vol 19 (28) ◽  
pp. 18529-18538 ◽  
Author(s):  
Francisco Adasme-Carreño ◽  
Jans Alzate-Morales ◽  
Joel Ireta
Keyword(s):  
Halogen Bonds ◽  
Cooperative Effects ◽  
Linear Chains ◽  
Cyanogen Halides ◽  
Infinite Linear

It is shown that the nature of halogen bonds in cyanogen halides and 4-halopyridines differs, still cooperativity in both systems results from interacting point-dipoles.

Notizen: Ca{Li2[Mn'N]2}: Kristallchemischer Brückenschlag Zwischen Lithium-Nitrido-Verbindungen und Borid-Carbiden des Typs M [B2C2]/ Ca{Li2[M nIN]2}: Link between Crystal Chemistry of Lithium Nitrido Compounds and Boride Carbides of the Type M [B2C2]

2000 ◽  
Vol 55 (10) ◽  
pp. 988-991 ◽  
Author(s):  
Jens Klatyk ◽  
Rainer Niewa ◽  
Rüdiger Kniep
Keyword(s):  
Crystal Structure ◽  
Crystal Chemistry ◽  
Stacking Sequence ◽  
Space Group ◽  
Linear Chains ◽  
Infinite Linear

AbstractThe nitridom anganate(I) Ca{Li2[MnIN]2) (space group P4/mbm: a = 703.35(7), c = 383.19(6) pm; Z = 2) contains infinite linear chains 1∞=[MnIN2/22-] running along the [001] direction. The nitride species of the chains are further linked via three coordinated lithium to form planar 4.82-nets 2∞{Li2N24-} parallel (001). Ca2+ occupies the centers of the eight-membered rings of the planar nets. The 4.82-arrangement 2∞{Li2N24-} together with the stacking sequence ...AA... along [001] exhibit strong topological similarities with the anionic substructure 2∞[B2C22-] observed in the crystal structure of e.g. Ce[B2C2]

Third-Order Electric Field Response of Infinite Linear Chains Composed of Phenalenyl Radicals

2016 ◽  
Vol 120 (12) ◽  
pp. 6756-6761 ◽  
Author(s):  
Simone Salustro ◽  
Lorenzo Maschio ◽  
Bernard Kirtman ◽  
Michel Rérat ◽  
Roberto Dovesi
Keyword(s):  
Electric Field ◽  
Third Order ◽  
Linear Chains ◽  
Field Response ◽  
Infinite Linear

Ab-initio Band Structure Calculations and 61 Ni-Mössbauer Studies of BaNiO2 , BaNiO3 and CaNiN

1996 ◽  
Vol 51 (5-6) ◽  
pp. 515-526 ◽  
Author(s):  
B. Hannebauer ◽  
P.C. Schmidt ◽  
R. Kniep ◽  
N. Jansen ◽  
D. Walcher ◽  
...  
Keyword(s):  
Band Structure ◽  
Orbital Method ◽  
Full Potential ◽  
Band Structure Calculations ◽  
Nickel Compounds ◽  
Linear Chains ◽  
Square Planar ◽  
Structure Calculations ◽  
Infinite Linear ◽  
Good Agreement

The electron density distribution of the nickel compounds BaNiO2 , BaNiO3 and CaNiN has been investigated experimentally by 61Ni Mössbauer spectroscopy and theoretically by band structure calculations using the FP-LMTO (Full Potential Linear Muffin-Tin Orbital) method. For all compounds good agreement is found between the experimental and theoretical values of the electric field gradient qexp. and qtheor. at the nickel site.BaNiO2 contains nickel in a square-planar coordination forming puckered chains of edge-sharing NiO4 squares. |q| at nickel is large: qexp = - 15.7(1.5) • 1021 Vm-2 and qtheor. = - 15.59 • 1021 Vm-2 .The principal axis z is perpendicular to the NiO4 squares. The crystal structure of BaNiO3 contains face-sharing chains of NiO6 octahedra. In BaNiO3 q(Ni) is small: qexp. = ± 3.6(2.0) • 1021 Vm-2 and qtheor. = - 1.86 • 1021 Vm-2 . Because of the small broadening of the Mössbauer resonance line the sign of q could not be determined experimentally.The nitridoniccolate CaNiN contains infinite linear chains 1∞[NiN2/2 ] which run perpendicular to the c axis. Unexpectedly, |q(Ni)| in CaNiN is small: qexp. = 0.0 (2.0) • 1021 Vm-2 and qtheor. = - 3.05 • 1021 Vm-2. Again the sign of q(Ni) could not be determined experimentally. It is found theoretically that the small value of q(Ni) is caused by severe cancellation between σ and π contributions.

Electrogeneration of Conducting Poly(α-tetrathiophene). Effect of Solution Stirring and Detection of Linear Oligomers

2003 ◽  
Vol 68 (7) ◽  
pp. 1326-1344 ◽  
Author(s):  
Francesc Estrany ◽  
Ramon Oliver ◽  
Esther García ◽  
Esther Gualba ◽  
Pere-Lluís Cabot ◽  
...  
Keyword(s):  
Ion Pairs ◽  
Polymer Chains ◽  
Polymerization Process ◽  
Anodic Process ◽  
Cathodic Peak ◽  
Linear Chains ◽  
Monomer Solution ◽  
Ir Analysis ◽  
Microscopy Images ◽  
Tof Ms

The anodic oxidation of α-tetrathiophene on Pt was studied in a 1.0 mM monomer solution in 0.1 M LiClO4 in 45:35:20 acetonitrile/ethanol/DMF. Three consecutive oxidation peaks were detected by cyclic voltammetry, along with a cathodic peak related to the reduction of electroactive polarons formed during the first anodic process. Uniform, adherent, insoluble and black polymer films were obtained by chronoamperometry at 1.000 V vs Ag|AgCl corresponding to the first oxidation-polymerization process. Stirring of monomer solution promotes the production of polymer, favoring the oxidation of polymer chains with the incorporation of more doping ClO4- ions and ion pairs of Li+ClO4- in their monomeric units. The conductivity of the polymer obtained under stirring was three orders of magnitude higher than that synthesized from a quiescent solution. The scanning electron microscopy images also showed much more uniform films under stirring. This behavior points to the existence of less crosslinking in the polymer and the production of longer linear chains when the solution is stirred. IR analysis of these materials confirmed the formation of crosslinked chains with predominance of β-β linkages. Short linear oligomers such as the dimer, trimer and tetramer were detected in all polymers by MALDI-TOF-MS, thus showing a radical polycondensation as initial electropolymerization mechanism. A larger proportion of linear oligomers is formed under solution stirring.

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