Synthesis of a Naphthalene-diimide Cyclophane for Tuning Supramolecular Interactions by Metal Ions

2012 ◽  
Vol 2012 (23) ◽  
pp. 4287-4292 ◽  
Author(s):  
Yanwen Yu ◽  
Yongjun Li ◽  
Songhua Chen ◽  
Taifeng Liu ◽  
Zhihong Qin ◽  
...  
Keyword(s):  
Metal Ions ◽  
Supramolecular Interactions ◽  
Naphthalene Diimide

Exploration of unconventional π–hole and C–H⋯H–C types of supramolecular interactions in a trinuclear Cd(ii) and a heteronuclear Cd(ii)–Ni(ii) complex and experimental evidence for preferential site selection of the ligand by 3d and 4d metal ions

RSC Advances ◽  
2016 ◽  
Vol 6 (45) ◽  
pp. 39376-39386 ◽  
Author(s):  
Saikat Banerjee ◽  
Antonio Bauzá ◽  
Antonio Frontera ◽  
Amrita Saha
Keyword(s):  
Schiff Base ◽  
Metal Ions ◽  
Experimental Evidence ◽  
Schiff Base Ligand ◽  
Site Selection ◽  
Supramolecular Interactions ◽  
Preferential Site ◽  
Selection Of

We report the synthesis of a trinuclear cadmium(ii) (1) and a di(phenoxido)-bridged dinuclear cadmium(ii)–nickel(ii) (2) complex derived from a bicompartmental (N2O4) Schiff base ligand.

scholarly journals Photochemical Reactions of Hydrogen-bonded Coordination Polymers

2014 ◽  
Vol 70 (a1) ◽  
pp. C529-C529
Author(s):  
Jagadese Vittal
Keyword(s):  
Metal Ions ◽  
Coordination Polymers ◽  
Structural Transformations ◽  
Photochemical Reactions ◽  
Supramolecular Interactions ◽  
Network Structures ◽  
Experimental Conditions ◽  
Hydrogen Bonding Interactions ◽  
Kinetic Phenomenon ◽  
Solvent Molecules

Crystallization is a kinetic phenomenon and the experimental conditions like solvents, concentration, pH, temperature and time have greater influence on the nature of products in the synthesis of coordination network structures. During crystallization, the solvents and ligands bind to the metal ions reversibly and hence, the least soluble polymer will crystallize first, independent of the metal-ligand ratio used in the crystallization. The kinetic products quite often contain solvents bonded to the metal ions. The removal of these coordinated solvents is likely to transform the kinetically formed coordination polymers (CPs) into thermodynamically stable products. In these structural conversions, supramolecular interactions play a major role. Such structural transformations as well as [2+2] cycloaddition reactions have been demonstrated in many coordination polymeric network structures aided by the directional hydrogen bonding interactions. A number of structural transformations involving the loss of solvent molecules and use of photodimerization reactions in the solid state will be presented in this talk.

Thermodynamic studies on supramolecular interactions of metal ions with nucleotides/tripods ligands

Polyhedron ◽  
2002 ◽  
Vol 21 (9-10) ◽  
pp. 1005-1015 ◽  
Author(s):  
Yan-He Guo ◽  
Qing-Chun Ge ◽  
Hai Lin ◽  
Hua-Kuan Lin ◽  
Shou-Rong Zhu
Keyword(s):  
Metal Ions ◽  
Supramolecular Interactions ◽  
Thermodynamic Studies

The recognition and catalytic hydrolysis of ATP by protonated phenanthroline-bridged polyamine and (or) Ca(II), Mg(II), Zn(II), and La(III) ions

2004 ◽  
Vol 82 (4) ◽  
pp. 504-512 ◽  
Author(s):  
Yan-He Guo ◽  
Qing-Chun Ge ◽  
Hai Lin ◽  
Hua-Kuan Lin ◽  
Shou-Rong Zhu
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Atp Hydrolysis ◽  
Amino Nitrogen ◽  
Supramolecular Interactions ◽  
Hydrolysis Rate ◽  
Catalytic Hydrolysis ◽  
Mixed Ligands ◽  
Hydrolysis Of ◽  
Protonated Ligand

The supramolecular interactions of 2,9-di(((2′-phenylamino)ethyleneamino)methyl)-1,10-phenanthroline (L) and (or) metal ions (M = Ca2+, Mg2+, Zn2+, or La3+) with nucleotides were investigated. Furthermore, the hydrolysis of ATP catalyzed by a protonated ligand and (or) a metal ion (M = Ca2+, Mg2+, Zn2+, or La3+) was studied at pH 7.6 using 31P NMR spectra. Kinetics studies show that at pH 7.6 the protonated ligand, with a rate constant of 2.9 × 10–4 min–1, does not significantly promote ATP hydrolysis. However, in the presence of Ca2+, Mg2+, Zn2+, or La3+ ions, L can accelerate the hydrolysis of ATP, with corresponding rate constants of 5.73, 1.48, 6.76, and 31.7 × 10–3 min–1, respectively, which are about 29-, 7.5-, 34-, and 159-fold faster than the hydrolysis rate of free ATP. By comparison with M–ATP (M = Ca2+, Mg2+, and La3+) systems, the rates of M–L–ATP were also promoted. This has been achieved through the effective recognition of ATP and the availability of a good intramolecular nucleophile, i.e., a free amino nitrogen atom of L. Compared with the Zn2+–ATP system, the decrease in the rate of the Zn2+–L–ATP system at pH 7.6 may be attributed to the competition between the mixed ligands in binding Zn2+. Similar to L–ATP, the hydrolysis reactions in the Zn2+–L–ATP or M–L–ATP (M = Ca2+, Mg2+, and La3+) systems occur through an addition–elimination type mechanism, in which phosphoramidate intermediates were observed at 2.88 and 4.06 parts per million (ppm) in the L–ATP and Mg2+–L–ATP systems, respectively. Here, metal ions add control or regulation to the hydrolysis reaction. Key words: recognition, ATP hydrolysis, metal ions, phenanthroline-bridged polyamine.

scholarly journals New Bis-Pyrazole-Bis-Acetate Based Coordination Complexes: Influence of Counter-Anions and Metal Ions on the Supramolecular Structures

2020 ◽  
Vol 13 (1) ◽  
pp. 288
Author(s):  
Afaf Oulmidi ◽  
Smaail Radi ◽  
Haralampos N. Miras ◽  
Nayarassery N. Adarsh ◽  
Yann Garcia
Keyword(s):  
Metal Ions ◽  
Single Crystal ◽  
Network Structure ◽  
Coordination Complexes ◽  
Supramolecular Structures ◽  
Supramolecular Interactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sheet Structure ◽  
Hydrogen Bonded

A new flexible bis-pyrazol-bis-acetate ligand, diethyl 2,2’-(pyridine-2,6-diylbis (5-methyl-1H-pyrazole-3,1-diyl))diacetate (L), has been synthesised, and three coordination complexes, namely, [Zn(L)2](BF4)2 (1), [MnLCl2] (2) and [CdLCl2] (3) have been obtained. All ligands and complexes were characterised by IR, mass spectroscopy, thermogravimetric analysis and single-crystal X-ray diffraction. Single crystal X-ray diffraction experiment revealed that the primary supramolecular building block of 1 is a hexagonal chair shaped 0D hydrogen bonded synthon (stabilised by C–H∙∙∙O hydrogen bonding and C=O∙∙∙π interactions), which further built into a 2D corrugated sheet-like architecture having a 3-c net honeycomb topology, and finally extended to a 3D hydrogen bonded network structure having a five nodal 1,3,3,3,7-c net, through C–H∙∙∙F interactions. On the other hand, the two crystallographically independent molecules of 2 exhibited two distinct supramolecular structures such as 2D hydrogen bonded sheet structure and 1D zigzag hydrogen bonded chain, sustained by C–H∙O and C–H∙∙∙Cl interactions, which are further self-assembled into a 3,4-c network structure, and 3 showed a 2D hydrogen bonded sheet structure. The supramolecular structural diversity in these complexes is due to the different conformations adopted by the ligands, which are mainly induced by different metal ions with coordination environments controlled by different anions. Hirshfeld surface analysis was explored for the qualitative and quantitative analysis of the supramolecular interactions.

HREM Study of electron-induced surface radiation damage in ReO3

1991 ◽  
Vol 49 ◽  
pp. 636-637
Author(s):  
R. Ai ◽  
H.-J. Fan ◽  
L. D. Marks
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Metal Oxides ◽  
Electron Irradiation ◽  
Transition Metal Oxides ◽  
Carbon Film ◽  
Transition Metal Ions ◽  
Surface Radiation ◽  
Valence Transition ◽  
Electron Microscopes

It has been known for a long time that electron irradiation induces damage in maximal valence transition metal oxides such as TiO2, V2O5, and WO3, of which transition metal ions have an empty d-shell. This type of damage is excited by electronic transition and can be explained by the Knoteck-Feibelman mechanism (K-F mechanism). Although the K-F mechanism predicts that no damage should occur in transition metal oxides of which the transition metal ions have a partially filled d-shell, namely submaximal valence transition metal oxides, our recent study on ReO3 shows that submaximal valence transition metal oxides undergo damage during electron irradiation.ReO3 has a nearly cubic structure and contains a single unit in its cell: a = 3.73 Å, and α = 89°34'. TEM specimens were prepared by depositing dry powders onto a holey carbon film supported on a copper grid. Specimens were examined in Hitachi H-9000 and UHV H-9000 electron microscopes both operated at 300 keV accelerating voltage. The electron beam flux was maintained at about 10 A/cm2 during the observation.

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