Coordination Assemblies of CoII, NiII, ZnII, and CuII with 3,3′,4,4′-Biphenyltetracarboxylic Acid and Three Positional Isomeric Ligands

2013 ◽  
Vol 66 (11) ◽  
pp. 1378 ◽  
Author(s):  
Wei Luo ◽  
Di Yao ◽  
Haiye Li ◽  
Fuping Huang ◽  
Qing Yu ◽  
...  

Eight different complexes with three positional isomeric dipyridyl ligands (3,3′-Hbpt, 3,4′-Hbpt, and 4,4′-Hbpt) (here, 3,3′-Hbpt = 1H-3,5-bis(3-pyridyl)-1,2,4-triazole, 3,4′-Hbpt = 1H-3-(3-pyridyl)-5-(4-pyridyl)-1,2,4-triazole, and 4,4′-Hbpt = 1H-3,5-bis(4-pyridyl)-1,2,4-triazole), as well as 3,3′,4,4′-biphenyltetracarboxylic acid (H4bptc), namely, {[M(bptc)0.5(3,3′-Hbpt)(H2O)2]·H2O}n (M = Co (1), M = Ni (2)), {[Zn2(bptc)(3,3′-Hbpt)2]·3H2O}n (3), [Co(bptc)0.5(3,4′-Hbpt)(H2O)]n (4), [Ni(bptc)0.5(3,4′-Hbpt)2(H2O)2]n (5), {[Cu(bptc)0.5(3,4′-Hbpt)(H2O)]·H2O}n (6), and {[M(bptc)0.5(4,4′-Hbpt)2(H2O)]·4H2O}n (M = Co (7), and Ni (8)) were synthesised and characterised by single-crystal X-ray diffraction. The crystallographic analysis demonstrates that bptc influences the MII (M = Co, Ni, Cu, and Zn) ions to form 2D layers, which are further connected via the isomeric bpt connectors, leading to many types of coordination polymers, such as 2D layers(for 1–3, 5), 3D four-connected nets with a short Schläfli symbol of (64.82) (for 4, 6), and 3D four-connected nets with a short Schläfli symbol of (64.82)(5.63.72)0.5 (for 7–8). This work demonstrates that the isomeric effects of the bpt ligands influence the construction of these frameworks. The thermal stability of complexes 1–6 was investigated.

2014 ◽  
Vol 67 (11) ◽  
pp. 1679
Author(s):  
Sheng Zhang ◽  
Qi Yang ◽  
Xiangyu Liu ◽  
Gang Xie ◽  
Qing Wei ◽  
...  

Five coordination polymers, [Cu(L)2]n (1), {[Cu(L)(Cl)(H2O)]·H2O}2n (2), [KCu(L)(μ-Cl)2]n (3), [Cu(L)(Br)H2O]n (4), and {[Cu0.5(HL)(H2O)](NO3)·H2O}2n (5) (HL = 5-methylpyrazine-2-carboxylic acid) were obtained by reactions of a pyramidal CuII-containing ligand, {[Cu(L)2(H2O)]·3H2O}n (LCu), with Gd(ClO4)3·6H2O, GdCl3·6H2O, GdCl3·6H2O/KCl, GdBr3·6H2O, or Gd(NO3)3·6H2O in water. Structural analysis reveals that the structures of these compounds range from a 0D block to a 2D network with modification of the environment of the CuII ions compared with LCu. Interestingly, there occurred a series of reversible dissolution/reorganization equilibriums between the initial reactants and the final products 1–5, which were determined as enthalpy/entropy driven chemical equilibriums by single crystal X-ray diffraction and microcalorimetry. In addition, the thermal stability of 1–4 and the magnetic property of 2 are discussed.


1998 ◽  
Vol 514 ◽  
Author(s):  
M. F. Wu ◽  
A. Vantomne ◽  
S. Hogg ◽  
H. Pattyn ◽  
G. Langouche ◽  
...  

ABSTRACTThe Nd-disilicide, which exists only in a tetragonal or an orthorhombic structure, cannot be grown epitaxially on a Si(111) substrate. However, by adding Y and using channeled ion beam synthesis, hexagonal Nd0.32Y0.68Si1.7 epilayers with lattice constant of aepi = 0.3915 nm and cepi = 0.4152 nm and with good crystalline quality (χmin of Nd and Y is 3.5% and 4.3 % respectively) are formed in a Si(111) substrate. This shows that the addition of Y to the Nd-Si system forces the latter into a hexagonal structure. The epilayer is stable up to 950 °C; annealing at 1000 °C results in partial transformation into other phases. The formation, the structure and the thermal stability of this ternary silicide have been studied using Rutherford backscattering/channeling, x-ray diffraction and transmission electron microscopy.


2021 ◽  
Vol 875 ◽  
pp. 116-120
Author(s):  
Muhammad Alamgir ◽  
Faizan Ali Ghauri ◽  
Waheed Qamar Khan ◽  
Sajawal Rasheed ◽  
Muhammad Sarfraz Nawaz ◽  
...  

In this study, the effect of SBR concentration (10 Phr, 20 Phr & 30 Phr ) on the thermal behavior of EPDM/SBR blends was studied. Thermogravimetric analysis (TGA) was used to check weight loss of samples as function of temperature by heating upto 600°C. X-ray diffraction (XRD) was performed to determine quality and % crystallinity of the elastomer blends. It was seen that % crystallinity improved with an increase in the content of SBR in EPDM/SBR blends. TGA revealed that the thermal stability of EPDM/SBR blends has improved by 17% than neat EPDM. Carbon nano-coatings produced by sputtering have no beneficial influence on thermal behaviour of elastomers.


2005 ◽  
Vol 60 (5) ◽  
pp. 505-510 ◽  
Author(s):  
Tong-Lai Zhang ◽  
Jiang-Chuang Song ◽  
Jian-Guo Zhang ◽  
Gui-Xia Ma ◽  
Kai-Bei Yu

Cobalt(II) and zinc(II) complexes of ethyl carbazate (ECZ), [Co(ECZ)3](NO3)2 and [Zn(ECZ)3] (NO3)2, were synthesized. Single crystals of these two compounds were grown from aqueous solutions using a slow evaporation method. Their structures have been determined by X-ray diffraction analysis. Both of them are monoclinic with space group P21/n. The complexes are further characterized by element analysis and IR measurements. Their thermal stabilities are studied by using TG-DTG, DSC techniques. When heated to 350 °C, only metal oxide was left for both complexes.


2005 ◽  
Vol 20 (10) ◽  
pp. 2682-2690 ◽  
Author(s):  
Yufang Zhu ◽  
Weihua Shen ◽  
Xiaoping Dong ◽  
Jianlin Shi

A stable mesoporous multilamellar silica vesicle (MSV) was developed with a gallery pore size of about 14.0 nm. A simulative enzyme, hemoglobin (Hb), was immobilized on this newly developed MSV and a conventional mesoporous silica material SBA-15. The structures and the immobilization of Hb on the mesoporous supports were characterized with x-ray diffraction, transmission electron microscopy, N2 adsorption-desorption isotherms, Fourier transform infrared, ultraviolet-visible spectroscopy, and so forth. MSV is a promising support for immobilizing Hb due to its large pore size and high Hb immobilization capacity (up to 522 mg/g) compared to SBA-15 (236 mg/g). Less than 5% Hb was leached from Hb/MSV at pH 6.0. The activity study indicated that the immobilized Hb retained most peroxidase activity compared to free Hb. Thermal stability of the immobilized Hb was improved by the proctetive environment of MSV and SBA-15. Such an Hb-mesoporous support with high Hb immobilization capacity, high activity, and enhanced thermal stability will be attractive for practical applications.


2018 ◽  
Vol 6 (35) ◽  
pp. 17171-17176 ◽  
Author(s):  
Lasse Rabøl Jørgensen ◽  
Jiawei Zhang ◽  
Christian Bonar Zeuthen ◽  
Bo Brummerstedt Iversen

The thermal stability of the high performance n-type Te-doped Mg3Sb1.5Bi0.5 system is investigated.


2020 ◽  
Vol 869 ◽  
pp. 61-68
Author(s):  
Egor A. Bersenev ◽  
Alina Maryasevskaya ◽  
Evgenii V. Komov ◽  
Denis V. Anokhin ◽  
Dimitri A. Ivanov

In the present paper we study the effect of complexation in linear negatively charged polyelectrolytes with different alkali ions. With combination of IR-spectroscopy, X-ray diffraction and nanocalorimetry, we attempted to explain unusual solubility, crystallinity and thermal stability of these polymers. The increase of thermal stability and insolubility in water in series of semi-crystalline polysalts as K+ ≤ H+ <Na+ was explained by effectiveness of formation of chelating complex. Insoluble in water sodium salt shows the highest thermal stability of crystal phase up to . In contrast, well soluble in water amorphous lithium salt does not self-organize in chelating complex and is presented in ionic form.


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