scholarly journals Study on the Photoluminescent and Thermal Properties of Zinc Complexes with a N6O4 Macrocyclic Ligand

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1735 ◽  
Author(s):  
Xingyong Xue ◽  
Qijun Wang ◽  
Fusen Mai ◽  
Xing Liang ◽  
Yichen Huang ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Macrocyclic Ligand ◽  
Quantum Yields ◽  
X Ray Diffraction ◽  
Coordination Environment ◽  
X Ray ◽  
Fluorescence Quantum Yields ◽  
Solid States ◽  
Trigonal Bipyramidal ◽  
Decomposition Processes

Reactions between a N6O4 macrocyclic ligand (L1) and several Zn(II) salts (trifluoromethane sulfonate, p-toluenesulfonate, acetate, benzoate, o-, m- or p-hydroxybenzoate) led to the formation of seven complexes, [Zn2L1 (DMSO)4](OSO2CF3)4 (1), [Zn2(p-OSO2PhCH3)4L1] (2), [Zn2(OCOCH3)4L1] (3), [Zn2(OCOPh)4L1] (4), [Zn2(o-OCOPhOH)4L1] (5), [Zn2(m-OCOPhOH)4 L1] (6) and [Zn2(p-OCOPhOH)4 L1] (7), which were characterized by elemental analysis, 1H-NMR, 13C-NMR, IR, fluorescence spectroscopies and single crystal X-ray diffraction. In 1, the Zn atom is pentacoordinated with a N3O2 irregular trigonal bipyramidal coordination environment, like the geometries in compounds 3–7, whereas in structure 2 the metal atom is envisaged as possessing a distorted N3O3 octahedronal environment. All the compounds show interesting photoluminescent properties in solid states and solutions in DMF and DMSO, which are reported along with their TG-DTA thermal decomposition processes, UV-vis absorption spectroscopy and fluorescence quantum yields in DMF and DMSO.

scholarly journals Solid-solid synthesis, characterization and thermal decomposition of a homodinuclear cobalt(II) complex

2015 ◽  
Vol 80 (11) ◽  
pp. 1391-1397 ◽  
Author(s):  
Di Li ◽  
Guo-Qing Zhong ◽  
Zhi-Xian Wu
Keyword(s):  
Thermal Decomposition ◽  
Raw Materials ◽  
Uv Spectra ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Monoclinic System ◽  
X Ray ◽  
Decomposition Processes ◽  
Elemental Analyses ◽  
Percentage Mass Loss

The homodinuclear cobalt(II) complex [Co2(dipic)2(H2O)5]?2H2O was synthesized with pyridine-2,6-dicarboxylic acid (H2dipic) and cobalt(II) acetate as raw materials by room temperature solid-solid reaction. The complex was characterized by elemental analyses, single crystal X-ray diffraction, X-ray powder diffraction, Fourier transform infrared spectroscopy, UV spectra, and thermogravimetry and differential scanning calorimetry. Its crystal structure belongs to monoclinic system and space group P2(1)/c. There are two types of the Co(II) ions, and they are all six-coordination, one Co(II) is coordinated by four carboxyl O atoms and two pyridine N atoms from two dipic2- anions, and another Co(II) is coordinated by five O atoms from five H2O molecules and one bridged carboxyl O atom from the dipic2- anion. The possible pyrolysis reactions in the thermal decomposition processes of the complex, the experimental and calculated percentage mass loss are also given.

Five-coordination in complexes of 2-(3,5-Dimethylpyrazol-1-yl)quinoline, a sterically hindered diimine system

1984 ◽  
Vol 37 (12) ◽  
pp. 2421 ◽  
Author(s):  
AT Baker ◽  
NJ Ferguson ◽  
HA Goodwin
Keyword(s):  
Water Molecule ◽  
Cobalt Complex ◽  
X Ray Diffraction ◽  
Iron Cobalt ◽  
Coordination Environment ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Cobalt Nickel ◽  
Metal Atoms ◽  
Sterically Hindered Diimine

The bidentate diimine-type ligand 2-(3,5-dimethylpyrazol-1-yl)quinoline forms mono complexes with the bivalent chlorides of iron, cobalt, nickel and copper. These complexes are magnetically dilute, but electronic spectral data indicate that, except for the cobalt complex which is tetrahedral, the metal atoms are five-coordinate and hence a chloro-bridged structure is proposed. The cobalt(II) complex readily adds a water molecule, and structure determination by X-ray diffraction shows that the complex aquadichloro[2-(3,5-dimethylpyrazol-1-yl)quinoline]cobalt(II) is monomeric and five-coordinate, the coordination environment approximating trigonal bipyramidal.

Crystal and molecular structure of diorganoammonium oxalatotrimethylstannate, [R2NH2][Me3Sn(C2O4)] (R=i-Bu, cyclohexyl)

2011 ◽  
Vol 34 (5-6) ◽  
pp. 127-130 ◽  
Author(s):  
Yaya Sow ◽  
Libasse Diop ◽  
Kieran C. Molloy ◽  
Gabrielle Kociok-Köhn
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bonds ◽  
Diffraction Study ◽  
Crystal And Molecular Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Trans Complex ◽  
A Chain ◽  
Distorted Trigonal Bipyramidal

Abstract The title compounds [R2NH2][C2O4SnMe3](R=i-Bu, Cy), in which tin atoms adopt a distorted trigonal bipyramidal configuration, have been prepared and submitted to an X-ray diffraction study. These compounds have been obtained from the reaction of (Cy2NH2)2C2O4·H2O or (i-Bu2NH2)2C2O4 with SnMe3Cl. In both [R2NH2][C2O4SnMe3] compounds, the trans complex has an almost regular trigonal bipyramidal geometry around the tin atom. The SnMe3 residues are connected as a chain with bridging oxalate anions in a trans-SnC3O2 framework, the oxygen atoms being in axial positions. The cations connect linear adjacent chains through NH…O hydrogen bonds giving layered structures.

Photochemical cis-trans Isomerization of 2-Substituted 9-(2-Nitroethenyl)anthracenes. X-Ray Structure Analyses of (E)- and (Z)-9-(2-Nitro-2-phenylethenyl)anthracene

1989 ◽  
Vol 42 (4) ◽  
pp. 593 ◽  
Author(s):  
HD Becker ◽  
BW Skelton ◽  
H Sorensen ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Quantum Yields ◽  
X Ray Diffraction ◽  
X Ray ◽  
Photostationary State ◽  
Trans Isomerization ◽  
Photochemical Isomerization

(E)-9-(2-Nitropropeny1)anthracene and (E)-9-(2-nitro-2-phenylethenyl)anthracene have been prepared by piperidine-catalysed condensation of 9-anthraldehyde with nitroethane and nitro(phenyl)methane, respectively. The corresponding (Z)-compounds were obtained by photochemical isomerization, quantum yields of geometrical isomerlzation being measured in cyclohexane, benzene, dichloromethane and ethanol. In virtually all solvents the (Z)-isomers are favoured at the photostationary state. The structures of (E)- and (2)-942- nitro-2-phenylethenyl)anthracene have been established by single-crystal X-ray diffraction studies.

scholarly journals A Facile Method to Construct MXene/CuO Nanocomposite with Enhanced Catalytic Activity of CuO on Thermal Decomposition of Ammonium Perchlorate

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2457 ◽  
Author(s):  
Haifeng Zhao ◽  
Jing Lv ◽  
Junshan Sang ◽  
Li Zhu ◽  
Peng Zheng ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Catalytic Activity ◽  
Ammonium Perchlorate ◽  
Photoelectron Spectra ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Improved Performance ◽  
Calcination Method

In this work, a mixing-calcination method was developed to facilely construct MXene/CuO nanocomposite. CuO and MXene were first dispersed in ethanol with sufficient mixing. After solvent evaporation, the dried mixture was calcinated under argon to produce a MXene/CuO nanocomposite. As characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and X-ray photoelectron spectra (XPS), CuO nanoparticles (60–100 nm) were uniformly distributed on the surface and edge of MXene nanosheets. Furthermore, as evaluated by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA), the high-temperature decomposition (HTD) temperature decrease of ammonium perchlorate (AP) upon addition of 1 wt% CuO (hybridized with 1 wt% MXene) was comparable with that of 2 wt% CuO alone, suggesting an enhanced catalytic activity of CuO on thermal decomposition of AP upon hybridization with MXene nanosheets. This strategy could be further applied to construct other MXene/transition metal oxide (MXene/TMO) composites with improved performance for various applications.

scholarly journals A Covalent Organic Cage Compound Acting as a Supramolecular Shadow Mask for the Regioselective Functionalization of C60

2020 ◽  
Author(s):  
Viktoria Leonhardt ◽  
Stefanie Fimmel ◽  
Ana-Maria Krause ◽  
Florian Beuerle
Keyword(s):  
Mass Spectrometry ◽  
Single Crystal ◽  
High Selectivity ◽  
Shadow Mask ◽  
X Ray Diffraction ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Cage Compound ◽  
Vis Spectroscopy ◽  
Regioselective Functionalization

<div><div><div><p>A trigonal-bipyramidal covalent organic cage compound serves as an efficient host to form stable 1:1-complexes with C60 and C70. Fullerene encapsulation has been comprehensively studied by NMR and UV/Vis spectroscopy, mass spectrometry as well as single-crystal X-ray diffraction. Exohedral functionalization of encapsulated C60 via threefold Prato reaction revealed high selectivity for the symmetry-matched all-trans-3 addition pattern.</p></div></div></div>

scholarly journals Crystal structure refinement of magnesium zinc divanadate, MgZnV2O7, from powder X-ray diffraction data

2021 ◽  
Vol 77 (6) ◽  
pp. 588-591
Author(s):  
Stephanie J. Hong ◽  
Jun Li ◽  
Mas A. Subramanian
Keyword(s):  
Crystal Structure ◽  
Diffraction Data ◽  
Structure Refinement ◽  
Atomic Ratio ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Wyckoff Position ◽  
Distorted Trigonal Bipyramidal

The crystal structure of magnesium zinc divanadate, MgZnV2O7, was determined and refined from laboratory X-ray powder diffraction data. The title compound was synthesized by a solid-state reaction at 1023 K in air. The crystal structure is isotypic with Mn0.6Zn1.4V2O7 (C2/m; Z = 6) and is related to the crystal structure of thortveitite. The asymmetric unit contains two metal sites with statistically distributed magnesium and zinc atoms with the atomic ratio close to 1:1. One (Mg/Zn) metal site (M1) is located on Wyckoff position 8j and the other (M2) on 4h. Three V sites (all on 4i), and eight O (three 8j, four 4i, and one 2b) sites complete the asymmetric unit. The structure is an alternate stacking of V2O7 layers and (Mg/Zn) atom layers along [20\overline{1}]. It is distinct from other related structures in that each V2O7 layer consists of two groups: a V2O7 dimer and a V4O14 tetramer. Mixed-occupied M1 and M2 are coordinated by oxygen atoms in distorted trigonal bipyramidal and octahedral sites, respectively.

X-ray diffraction study of oxygen-conducting compoundsLn2Mo2O9(Ln= La, Pr)

2014 ◽  
Vol 70 (4) ◽  
pp. 669-675 ◽  
Author(s):  
Alexander M. Antipin ◽  
Olga A. Alekseeva ◽  
Natalia I. Sorokina ◽  
Alexandra N. Kuskova ◽  
Michail Yu. Presniakov ◽  
...  
Keyword(s):  
Room Temperature ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Ion Migration ◽  
Transmission Microscopy ◽  
Coordination Environment ◽  
X Ray ◽  
Oxygen Ions ◽  
Oxygen Ion ◽  
Oxygen Ion Migration

The La2Mo2O9(LM) and Pr2Mo2O9(PM) single crystals are studied using precision X-ray diffraction and high-resolution transmission microscopy at room temperature. The crystal structures are determined in the space groupP213. La and Pr atoms, as well as Mo1 and O1 atoms, are located in the vicinity of the threefold axes rather than on the axes as in the high-temperature cubic phase. In both structures studied, the O2 and O3 positions are partially occupied. The coexistence of different configurations of the Mo coordination environment facilitates the oxygen-ion migration in the structure. Based on the X-ray data, the activation energies of O atoms are calculated and the migration paths of oxygen ions in the structures are analysed. The conductivity of PM crystals is close to that of LM crystals. The O2 and O3 atoms are the main contributors to the ion conductivity of LM and PM.

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