Molecular structure, optical and magnetic properties of the {SnIVPc(3-)Cl2}•- radical anions containing negatively charged Pc ligands

2014 ◽  
Vol 18 (12) ◽  
pp. 1157-1163 ◽  
Author(s):  
Dmitri V. Konarev ◽  
Sergey I. Troyanov ◽  
Maxim A. Faraonov ◽  
Manabu Ishikawa ◽  
Akihiro Otsuka ◽  
...  
Keyword(s):  
Effective Magnetic Moment ◽  
Room Temperature ◽  
Blue Shift ◽  
Ammonium Cation ◽  
Antiferromagnetic Coupling ◽  
Radical Anions ◽  
Weiss Temperature ◽  
Overlap Integral ◽  
One Dimensional ◽  
Epr Signal

Radical anion salt ( PPN +){ Sn IV Pc (3-) Cl 2}•- (1) was obtained by the reduction of tin(IV) phthalocyanine dichloride { Sn IV Pc (2-) Cl 2} with ( PPN +)( C 60•-) ( PPN + is bis(triphenylphosphoranylidene)-ammonium cation). It was shown that the reduction is centered mainly on the Pc ligand providing the appearance of a new band in the spectrum of 1 in the NIR range at 1006 nm and blue-shift of Soret and Q-bands of Sn IV Pc (2-) Cl 2. The alternation of short and long C – N imine bonds for two oppositely located isoindole units in 1 indicates possible disruption of aromaticity of the Pc ligand under reduction. Salt 1 has effective magnetic moment of 1.69 μB at 300 K corresponding to the contribution of one non-interacting S = 1/2 spin per formula unit and manifests antiferromagnetic coupling of spins with Weiss temperature of -7.3 K in the 400–30 K range. The salt shows a broad EPR signal with g = 1.9957 and linewidth of 19.3 mT at room temperature. The signal splits into two components below 120 K. Strong broadening of the EPR signal and shift of g-factors to smaller values in comparison with the EPR signal from radical anions of metal-free phthalocyanine { H 2 Pc (3-)}•- were attributed to the contribution of the { Sn III Pc (2-) Cl 2}- admixture with paramagnetic Sn III . There are π–π stacking one-dimensional chains composed of { Sn IV Pc (3-) Cl 2}•- in 1 along the a axis with weak overlapping between phenylene groups of phthalocyanine radical anions. The calculated HOMO–HOMO overlap integral is 0.0033 and the SOMO–SOMO overlap integral is only 0.0004. Metallic conductivity is not realized in 1 most probably due to weak SOMO–SOMO overlapping.

Magnetic susceptibility study of Te-rich Mnx Te1−x

1987 ◽  
Vol 2 (2) ◽  
pp. 239-243 ◽  
Author(s):  
X. M. Zou ◽  
John A. Gardner
Keyword(s):  
Magnetic Susceptibility ◽  
Effective Magnetic Moment ◽  
Room Temperature ◽  
Eutectic Temperature ◽  
Metastable Equilibrium ◽  
Temperature Dependent ◽  
Weiss Temperature ◽  
Effective Moment ◽  
Susceptibility Study ◽  
Magnetic Susceptibility Study

The magnetic susceptibility of Te, MnTe2, and three dilute TeMn alloys was measured from room temperature to 800°C. The effective magnetic moment of dilute Mn in liquid Te is 5.0(2) μB and appears to be slightly temperature dependent. The effective moment for Mn in MnTe2 is 6.05 μB, approximately equal to that of a free 5/2 spin. The Weiss temperature of MnTe2 is 610(20) K. These data are used to determine an accurate phase diagram for Terich Mnx Te1−x. The eutectic is found at 0.6(1) at. % Mn with a eutectic temperature within 2°C of the tellurium melting temperature. Because liquid tellurium remains in metastable equilibrium with solid MnTe2 as much as 80°C below the eutectic, a metastable lowtemperature extension of the liquidus is also determined.

Crystal structure of the anticancer drug carmustine determined by X-ray powder diffraction

2021 ◽  
pp. 1-3
Author(s):  
Carina Schlesinger ◽  
Edith Alig ◽  
Martin U. Schmidt
Keyword(s):  
Crystal Structure ◽  
Anticancer Drug ◽  
Powder Diffraction ◽  
Room Temperature ◽  
Powder Diffraction Data ◽  
Orthorhombic Space Group ◽  
Commercial Sample ◽  
One Dimensional ◽  
X Ray ◽  
Hydrogen Bond Pattern

The structure of the anticancer drug carmustine (1,3-bis(2-chloroethyl)-1-nitrosourea, C5H9Cl2N3O2) was successfully determined from laboratory X-ray powder diffraction data recorded at 278 K and at 153 K. Carmustine crystallizes in the orthorhombic space group P212121 with Z = 4. The lattice parameters are a = 19.6935(2) Å, b = 9.8338(14) Å, c = 4.63542(6) Å, V = 897.71(2) ų at 153 K, and a = 19.8522(2) Å, b = 9.8843(15) Å, c = 4.69793(6) Å, V = 921.85(2) ų at 278 K. The Rietveld fits are very good, with low R-values and smooth difference curves of calculated and experimental powder data. The molecules form a one-dimensional hydrogen bond pattern. At room temperature, the investigated commercial sample of carmustine was amorphous.

A new one-dimensional CdIIcoordination polymer with a two-dimensional layered structure incorporating 2-[(1H-imidazol-1-yl)methyl]-1H-benzimidazole and benzene-1,2-dicarboxylate ligands

2016 ◽  
Vol 72 (6) ◽  
pp. 480-484 ◽  
Author(s):  
Qiu-Ying Huang ◽  
Xiao-Yi Lin ◽  
Xiang-Ru Meng
Keyword(s):  
Layered Structure ◽  
Room Temperature ◽  
Weak Interactions ◽  
Coordination Geometry ◽  
Dimensional Chain ◽  
Two Dimensional ◽  
One Dimensional ◽  
Heterocyclic Ligand ◽  
Rich Variety ◽  
Solvent Molecules

The N-heterocyclic ligand 2-[(1H-imidazol-1-yl)methyl]-1H-benzimidazole (imb) has a rich variety of coordination modes and can lead to polymers with intriguing structures and interesting properties. In the coordination polymercatena-poly[[cadmium(II)-bis[μ-benzene-1,2-dicarboxylato-κ4O1,O1′:O2,O2′]-cadmium(II)-bis{μ-2-[(1H-imidazol-1-yl)methyl]-1H-benzimidazole}-κ2N2:N3;κ2N3:N2] dimethylformamide disolvate], {[Cd(C8H4O4)(C11H10N4)]·C3H7NO}n, (I), each CdIIion exhibits an irregular octahedral CdO4N2coordination geometry and is coordinated by four O atoms from two symmetry-related benzene-1,2-dicarboxylate (1,2-bdic2−) ligands and two N atoms from two symmetry-related imb ligands. Two CdIIions are connected by two benzene-1,2-dicarboxylate ligands to generate a binuclear [Cd2(1,2-bdic)2] unit. The binuclear units are further connected into a one-dimensional chain by pairs of bridging imb ligands. These one-dimensional chains are further connected through N—H...O hydrogen bonds and π–π interactions, leading to a two-dimensional layered structure. The dimethylformamide solvent molecules are organized in dimeric pairsviaweak interactions. In addition, the title polymer exhibits good fluorescence properties in the solid state at room temperature.

Polar Optical Phonon Instability and Intervalley Transfer in Gallium Nitride

1998 ◽  
Vol 512 ◽  
Author(s):  
B. E. Foutz ◽  
S. K. O'leary ◽  
M. S. Shur ◽  
L. F. Eastman ◽  
B. L. Gelmont ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
Analytical Model ◽  
Optical Phonon ◽  
Room Temperature ◽  
Phonon Scattering ◽  
Polar Optical Phonon ◽  
Scattering Mechanism ◽  
Loss Mechanism ◽  
One Dimensional ◽  
Optical Phonon Scattering

ABSTRACTWe develop a simple, one-dimensional, analytical model, which describes electron transport in gallium nitride. We focus on the polar optical phonon scattering mechanism, as this is the dominant energy loss mechanism at room temperature. Equating the power gained from the field with that lost through scattering, we demonstrate that beyond a critical electric field, 114 kV/cm at T = 300 K, the power gained from the field exceeds that lost due to polar optical phonon scattering. This polar optical phonon instability leads to a dramatic increase in the electron energy, this being responsible for the onset of intervalley transitions. The predictions of our analytical model are compared with those of Monte Carlo simulations, and are found to be in satisfactory agreement.

Room Temperature Electron Paramagnetic Resonance (EPR) Signal Storage

1969 ◽  
Author(s):  
D.A. Bozanic ◽  
D.C. Buck ◽  
F.H. Harris ◽  
R.E. Huber ◽  
D. Mergerian ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Room Temperature ◽  
Paramagnetic Resonance ◽  
Temperature Electron ◽  
Epr Signal ◽  
Electron Paramagnetic

scholarly journals Control of Structure and Magnetic Interaction Through Ligand Design: One-Dimensional Complexes from Ferromagnetic to Antiferromagnetic Coupling

2008 ◽  
Vol 2008 (2) ◽  
pp. 312-321 ◽  
Author(s):  
Wen-Zhen Wang ◽  
Rayyat Huseyn Ismayilov ◽  
Gene-Hsiang Lee ◽  
Hsin-Ta Wang ◽  
Rui-Ren Wang ◽  
...  
Keyword(s):  
Ligand Design ◽  
Magnetic Interaction ◽  
Antiferromagnetic Coupling ◽  
One Dimensional

Synthesis and Luminescence Properties of Tris (8-Hydroxyquinoline) Iron Spindle-Like Structures at Room Temperature

2011 ◽  
Vol 391-392 ◽  
pp. 225-229 ◽  
Author(s):  
Qing Hong Kong ◽  
Hong Liu ◽  
Yun Long Zhang ◽  
Yong Sheng Yan
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Blue Shift ◽  
Solvent System ◽  
Iron Complex ◽  
Molecular Formula ◽  
Gravimetric Analysis ◽  
Element Analysis ◽  
Transmission Electron ◽  
Fourier Transformation Infrared Spectroscopy

Spindle-like bis (8-hydroxyquinoline) iron (FeQ3) complex has been synthesized with a facile method in a mixed solvent system at room temperature for 12 h. The molecular formula of the products is speculated by the C, H and N element analysis and thermal gravimetric analysis, and Fourier-transformation infrared spectroscopy was also utilized to measure its structure, which further confirm the molecular formula of the products. The observation of field emission scanning electron microscopy and transmission electron microscopy shows that the morphology of tris (8-hydroxyquinoline) iron complex is spindle-like structure. The photoluminescence of the products were also investigated. The results indicate that the photoluminescence emission of FeQ3spindles shows obvious blue shift contrasted with that of 8-hydroxyquinoline.

scholarly journals Influence of the Para-Substituent in Lanthanoid Complexes of Bistetrazole Substituted Calix[4]arenes

2019 ◽  
Author(s):  
Rene Z.H. Phe ◽  
Brian Skelton ◽  
Massimiliano Massi ◽  
Mark Ogden
Keyword(s):  
Structural Changes ◽  
Cluster Formation ◽  
Ammonium Cation ◽  
Ammonium Salts ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
Mononuclear Complexes ◽  
Scattering Measurements ◽  
The Impact

5,11,17,23-Tetra-tert-butyl-25,27-dihydroxy-26,28-bis(tetrazole-5-ylmethoxy)calix[4]arene has been reported to form remarkable Ln19 and Ln12 elongated clusters, upon addition of aqueous ammonium carboxylates. The impact of the <i>para</i> substituent on lanthanoid cluster formation has been studied by synthesising two new bis-tetrazole calixarenes, with <i>p</i>-H, and <i>p</i>-allyl substituents. Solution phase dynamic light scattering measurements of the reaction mixtures indicated that clusters are not formed with the <i>p</i>-H and <i>p</i>-allyl derivatives, in contrast with the behaviour of the <i>t-</i>butyl analogue. Lanthanoid complexes of the <i>p</i>-H and <i>p</i>-allyl calixarenes were characterised by single crystal X-ray diffraction, and were found to form mononuclear complexes, linked to form a one-dimensional coordination polymer for the <i>p</i>-allyl system. All of the complexes were isolated as ammonium salts, with ammonium cation included in the calixarene cavity in most cases. It is concluded that the nature of the <i>para</i> substituent has a profound impact on the lanthanoid cluster formation process, and derivatives with more subtle structural changes will be required to determine if additional lanthanoid “bottlebrush” clusters can be isolated.<br><br>

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