scholarly journals ZnII Complexes Based on Hybrid N-Pyrazole, N′-imine Ligands: Synthesis, X-Ray Crystal Structure, NMR Characterisation, and 3D Supramolecular Properties

2015 ◽  
Vol 68 (5) ◽  
pp. 749 ◽  
Author(s):  
Miguel Guerrero ◽  
Lourdes Rivas ◽  
Teresa Calvet ◽  
Mercè Font-Bardia ◽  
Josefina Pons
Keyword(s):  
Crystal Engineering ◽  
Self Assembly ◽  
High Efficiency ◽  
Present Report ◽  
Three Dimensional ◽  
Molecular Complexes ◽  
X Ray ◽  
Elemental Analyses ◽  
Intermolecular Contacts ◽  
Bonding Properties

The present report is on the synthesis of two new 3-imine-3,5-dimethylpyrazole ligands, N-[3-(3,5-dimethyl-1H-pyrazol-1-yl)propylidene]ethylamine (L1) and N-[3-(3,5-dimethyl-1H-pyrazol-1-yl)propylidene]propylamine (L2). These ligands form molecular complexes with the formula [ZnCl2(L)] (L = L1 (1) and L2 (2)) when the reacting with ZnCl2 in a metal (M)/ligand (L) ratio of 1 : 1. These new ZnII complexes have been characterised by elemental analyses, conductivity measurements, mass spectrometry, and infrared, 1H and 13C{1H} NMR spectroscopy techniques. The two crystalline structures of complexes 1 and 2 have been solved by X-ray diffraction methods. Finally, we have studied the self-assembly three-dimensional supramolecular structure through different intra- and intermolecular contacts. The application of these ZnII complexes in supramolecular crystal engineering is interesting due to (1) the easy preparation and the high efficiency of this system and (2) the different bonding properties of the heteroatoms (N-pyrazole vs N-imine) present in the structure of the ligands.

scholarly journals Supramolecular architectures of 4-hydroxytetraphenylporphyrin with aza-donors

2014 ◽  
Vol 70 (a1) ◽  
pp. C554-C554 ◽  
Author(s):  
Purnendu Nandy ◽  
V. Pedireddi
Keyword(s):  
Three Dimensional ◽  
Molecular Complexes ◽  
Hydroxyl Groups ◽  
X Ray Diffraction ◽  
X Ray ◽  
Supramolecular Architectures ◽  
Detailed Structural Analysis ◽  
Different Types ◽  
Solvent Molecules ◽  
Molecular Adducts

Molecular adducts of 5,10,15,20-tetrakis(4-hydroxyphenyl)porphyrin (1) with aza-donors like 4,4'-bipyridine (a), 1,2-bis(4-pyridyl)ethane (b), trans-1,2-bis(4-pyridyl)ethylene (c), 4,4'-trimethylene-dipyridine (d), phenazine (e), 1,10-phenanthroline (f), 1,7-phenanthroline (g) and 4,7-phenanthroline (h) have been prepared. All the molecular complexes are crystallized along with the solvent of crystallization, except in the complex with the aza-donor b. Detailed structural analysis of the obtained complexes has been carried out by single crystal X-ray diffraction. The three dimensional structures of the molecular adducts are facilitated by directional hydrogen bonding features of hydroxyl groups with aza donors as well as solvent molecules, leading to the formation of different types of supramolecular architectures like sheets, tapes, host-guest assembly etc. For example, in the complex of 1 and aza donor a, which crystallizes as a hydrate, the porphyrin molecules interact with water and 4,4'-bipyridine through O-H...O and O-H...N hydrogen bonds, which leads to the formation of molecular sheets in two dimensional arrangement. An important noteworthy observation is that the molecular complexes are crystalline even after removal of the solvents by heating, as characterized by thermogravimetric analysis (TGA) and powder X-ray diffraction (PXRD). Further, all the complexes are found to be fluorescence sensitive, perhaps due to the porphyrin molecules.

scholarly journals An Unexpected Trinuclear Cobalt(II) Complex Based on a Half-Salamo-Like Ligand: Synthesis, Crystal Structure, Hirshfeld Surface Analysis, Antimicrobial and Fluorescent Properties

Crystals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 408 ◽  
Author(s):  
Ruo-Yan Li ◽  
Xiao-Xin An ◽  
Juan-Li Wu ◽  
You-Peng Zhang ◽  
Wen-Kui Dong
Keyword(s):  
Crystal Structure ◽  
Surface Analysis ◽  
Three Dimensional ◽  
Antimicrobial Activities ◽  
Hirshfeld Surface ◽  
Hirshfeld Surface Analysis ◽  
Fluorescent Properties ◽  
X Ray ◽  
X Ray Crystallography ◽  
Elemental Analyses

An unexpected trinuclear Co(II) complex, [Co3(L2)2(μ-OAc)2(CH3OH)2]·2CH3OH (H2L2 = 4,4′-dibromo-2,2′-[ethylenedioxybis(nitrilomethylidyne)]diphenol) constructed from a half-Salamo-based ligand (HL1 = 2-[O-(1-ethyloxyamide)]oxime-4-bromophenol) and Co(OAc)2·4H2O, has been synthesized and characterized by elemental analyses, infrared spectra (IR), UV-Vis spectra, X-ray crystallography and Hirshfeld surface analysis. The Co(II) complex contains three Co(II) atoms, two completely deprotonated (L2)2− units, two bridged acetate molecules, two coordinated methanol molecules and two crystalline methanol molecules, and finally, a three-dimensional supramolecular structure with infinite extension was formed. Interestingly, during the formation of the Co(II) complex, the ligand changed from half-Salamo-like to a symmetrical single Salamo-like ligand due to the bonding interactions of the molecules. In addition, the antimicrobial activities of HL1 and its Co(II) complex were also investigated.

Construction of a three-dimensional supramolecular framework based on an anionic cadmium(II) coordination network and protonated dipyridine organic cations

2018 ◽  
Vol 74 (8) ◽  
pp. 889-893
Author(s):  
Qian-Kun Zhou ◽  
Lin Wang ◽  
Dong Liu
Keyword(s):  
Hydrogen Bonding ◽  
Self Assembly ◽  
Title Compound ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Coordination Network ◽  
Hydrogen Bonding Interactions ◽  
Point Symbol

As a class of multifunctional materials, crystalline supramolecular complexes have attracted much attention because of their unique architectures, intriguing topologies and potential applications. In this article, a new supramolecular compound, namely catena-poly[4,4′-(buta-1,3-diene-1,4-diyl)dipyridin-1-ium [(μ4-benzene-1,2,4,5-tetracarboxylato-κ6 O 1,O 1′:O 2:O 4,O 4′:O 5)cadmium(II)]], {(C14H14N2)[Cd(C10H2O8)]} n or {(1,4-H2bpbd)[Cd(1,2,4,5-btc)]} n , has been prepared by the self-assembly of Cd(NO3)2·4H2O, benzene-1,2,4,5-tetracarboxylic acid (1,2,4,5-H4btc) and 1,4-bis(pyridin-4-yl)buta-1,3-diene (1,4-bpbd) under hydrothermal conditions. The title compound has been structurally characterized by IR spectroscopy, elemental analysis, powder X-ray diffraction and single-crystal X-ray diffraction analysis. Each CdII centre is coordinated by six O atoms from four different (1,2,4,5-btc)4− tetraanions. Each CdII cation, located on a site of twofold symmetry, binds to four carboxylate groups belonging to four separate (1,2,4,5-btc)4− ligands. Each (1,2,4,5-btc)4− anion, situated on a position of \overline{1} symmetry, binds to four crystallographically equivalent CdII centres. Neighbouring CdII cations interconnect bridging (1,2,4,5-btc)4− anions to form a three-dimensional {[Cd(1,2,4,5-btc)]2−} n anionic coordination network with infinite tubular channels. The channels are visible in both the [1\overline{1}0] and the [001] direction. Such a coordination network can be simplified as a (4,4)-connected framework with the point symbol (4284)(4284). To balance the negative charge of the metal–carboxylate coordination network, the cavities of the network are occupied by protonated (1,4-H2bpbd)2+ cations that are located on sites of twofold symmetry. In the crystal, there are strong hydrogen-bonding interactions between the anionic coordination network and the (1,4-H2bpbd)2+ cations. Considering the hydrogen-bonding interactions, the structure can be further regarded as a three-dimensional (4,6)-connected supramolecular architecture with the point symbol (4264)(42687·84). The thermal stability and photoluminescence properties of the title compound have been investigated.

Synthesis, structure and photocatalytic degradation of organic dyes of a copper(II) metal–organic framework (Cu–MOF) with a 4-coordinated three-dimensional CdSO4 topology

2019 ◽  
Vol 75 (8) ◽  
pp. 1053-1059 ◽  
Author(s):  
Lin-Lu Qian ◽  
Zhi-Xiang Wang ◽  
Hai-Xin Tian ◽  
Min Li ◽  
Bao-Long Li ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Crystal Engineering ◽  
Photoelectron Spectroscopy ◽  
Organic Dyes ◽  
Metal Organic Framework ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Organic ◽  
And Storage

Metal–organic frameworks (MOFs) have attracted much interest in the fields of gas separation and storage, catalysis synthesis, nonlinear optics, sensors, luminescence, magnetism, photocatalysis gradation and crystal engineering because of their diverse properties and intriguing topologies. A Cu–MOF, namely poly[[(μ2-succinato-κ2 O:O′){μ2-tris[4-(1,2,4-triazol-1-yl)phenyl]amine-κ2 N:N′}copper(II)] dihydrate], {[Cu(C4H4O4)(C24H18N10)]·2H2O} n or {[Cu(suc)(ttpa)]·2H2O} n , (I), was synthesized by the hydrothermal method using tris[4-(1,2,4-triazol-1-yl)phenyl]amine (ttpa) and succinate (suc2−), and characterized by IR, powder X-ray diffraction (PXRD), luminescence, optical band gap and valence band X-ray photoelectron spectroscopy (VB XPS). Cu–MOF (I) shows a twofold interpenetrating 4-coordinated three-dimensional CdSO4 topology with point symbol {65·8}. It presents good photocatalytic degradation of methylene blue (MB) and rhodamine B (RhB) under visible-light irradiation. A photocatalytic mechanism was proposed and confirmed.

Molecular tectonics — Use of urethanes and ureas derived from tetraphenylmethane and tetraphenylsilane to build porous chiral hydrogen-bonded networks

2004 ◽  
Vol 82 (2) ◽  
pp. 386-398 ◽  
Author(s):  
Dominic Laliberté ◽  
Thierry Maris ◽  
James D Wuest
Keyword(s):  
Hydrogen Bonding ◽  
Asymmetric Catalysis ◽  
Crystal Engineering ◽  
Three Dimensional ◽  
Enantiomerically Pure ◽  
X Ray ◽  
Molecular Tectonics ◽  
X Ray Crystallography ◽  
Open Networks ◽  
Hydrogen Bonded

Tetraphenylmethane, tetraphenylsilane, and simple derivatives with substituents that do not engage in hydrogen bonding typically crystallize as close-packed structures with essentially no space available for the inclusion of guests. In contrast, derivatives with hydrogen-bonding groups are known to favor the formation of open networks that include significant amounts of guests. To explore this phenomenon, we synthesized six new derivatives 5a–5e and 6a of tetraphenylmethane and tetraphenylsilane with urethane and urea groups at the para positions, crystallized the compounds, and determined their structures by X-ray crystallography. As expected, all six compounds crystallize to form porous three-dimensional hydrogen-bonded networks. In the case of tetraurea 5e, 66% of the volume of the crystals is accessible to guests, and guests can be exchanged in single crystals without loss of crystallinity. Of special note are: (i) the use of tetrakis(4-isocyanatophenyl)methane (1f) as a precursor for making enantiomerically pure tetraurethanes and tetraureas, including compounds 5b, 5c; and (ii) their subsequent crystallization to give porous chiral hydrogen-bonded networks. Such materials promise to include chiral guests enantioselectively and to be useful in the separation of racemates, asymmetric catalysis, and other applications.Key words: crystal engineering, molecular tectonics, hydrogen bonding, networks, porosity, urethanes, ureas, tetraphenylmethane, tetraphenylsilane.

Laser Controlled Dynamic Self-Assembly of Nanostructure

2017 ◽  
Vol 49 ◽  
pp. 225-231 ◽  
Author(s):  
Li Nan Zhang ◽  
Wei Zheng ◽  
Cong Xiu Cheng ◽  
Li Qun Wu
Keyword(s):  
Phase Field ◽  
Self Assembly ◽  
Numerical Stability ◽  
High Efficiency ◽  
Field Model ◽  
High Reliability ◽  
Three Dimensional ◽  
Phase Field Model ◽  
Heating Effect ◽  
Surface Fabrication

This paper presents a three-dimensional dynamic model of laser controlled dynamic self-assembly of nanostructure. A phase field model is employed to study the surface fabrication of silicon which is induced by the laser. The mechanism of the surface fabrication is that the heating effect enhances surface diffusion mobility results in atoms outward flow. The computational model systematically integrate for high reliability of the whole analysis, the experimental and simulated measurements have been quantitatively investigated. A semi-implicit Fourier spectral scheme is applied for high efficiency and numerical stability. The performed simulations suggest a substantial potential of the presented model, which provides a reliable technology of nanostructure fabrications on the surface of silicon.

scholarly journals Preparation and Characterization of 2-Phenoxyethyl(thiophen-2-yl)tellane (C4H3S)TeCH2CH2OC6H5

2006 ◽  
Vol 61 (1) ◽  
pp. 61-64
Author(s):  
Ludmila Vigo ◽  
Raija Oilunkaniemi ◽  
Risto S. Laitinen
Keyword(s):  
Three Dimensional ◽  
Monoclinic Crystal ◽  
X Ray ◽  
Compound C ◽  
Dimensional Network ◽  
Cell Dimensions ◽  
Weak Hydrogen Bonds ◽  
Intermolecular Contacts ◽  
Unit Cell Dimensions

The synthesis and structure of (C4H3S)TeCH2CH2OC6H5 (1) (C4H3S = thiophen-2-yl) are reported and compared to those of the analogous selenium compound (C4H3S)SeCH2CH2OC6H5 previously synthesized by our group. The compound was characterized by 1H, 13C{1H}-, and 125Te- NMR spectroscopy as well as by X-ray single crystal crystallography. 1 crystallizes in the monoclinic crystal system, space group P21, with Z = 2, and unit cell dimensions a = 10.618(2) Å , b = 5.357(1) Å , c = 10.684(2) Å , β = 96.57(3)°. The lattice is composed of discrete molecules that are joined together by weak hydrogen bonds into a three-dimensional network. The thiophen-2-yl ring is disordered and shows two alternative orientations with the site occupation factors of 0.70(1) and 0.30(1). All bond parameters are quite normal. The comparison of the lattices in 1 and in its selenium anologue shows that while the closest intermolecular contacts are similar, the packing of the molecules is different.

Collagen: the organic matrix of bone

1984 ◽  
Vol 304 (1121) ◽  
pp. 455-477 ◽  
Keyword(s):  
Self Assembly ◽  
Hexagonal Lattice ◽  
Three Dimensional ◽  
Organic Matrix ◽  
Calcium Hydroxyapatite ◽  
Collagen Molecule ◽  
Crystalline Region ◽  
X Ray ◽  
Molecular Arrangement ◽  
Diffraction Patterns

Collagen is the principal organic matrix in bone. The triple helical region of the molecule is 1014 amino acids long. In fibrils these molecules are staggered axially by integers of 234 residues or 68 nm ( D ). This axial shift occurs by self-assembly and can be understood in terms of a periodicity in the occurrence of apolar and polar residues in the amino acid sequence. Because the molecular length L = 4.47 D , there are gaps 1.5 x 36.5 nm regularly arrayed throughout the fibrils. The three-dimensional molecular arrangement is a quasi-hexagonal lattice with three distinct values for the principal interplanar spacings. Analysis of the intensity distribution in the medium-angle X -ray diffraction patterns from tendons has produced the following picture of the molecular arrangement in fibrils (Fraser et al . 1983). The molecular helices have a coherent length of 32 nm and are tilted parallel to a specific place within the lattice. A regular azimuthal interaction exists between these helices. This crystalline region could be the overlap region with a non-crystalline gap region. However, the gap is still regular axially and the molecular helices retain their structure; their lateral packing is perturbed although they retain a ‘gap’. Neutron and X -ray scattering experiments have shown that calcium hydroxyapatite crystals occur in the gap and are nucleated at a specific though unknown location within the gap. The c -axis of the apatite crystals is parallel to the fibril axis and its length c = 0.688 nm is close to the axial periodicity in a protein with an extended β-conformation. If the telopeptides at the end of a collagen molecule do have this conformation they would either have a highly heterogeneous conformation or exist in a folded manner because the overall length of the telopeptides is shorter than a regular collagen repeat of 0.029 nm would allow.

X-ray characterization of contact holes for block copolymer lithography

2019 ◽  
Vol 52 (1) ◽  
pp. 106-114
Author(s):  
Daniel F. Sunday ◽  
Florian Delachat ◽  
Ahmed Gharbi ◽  
Guillaume Freychet ◽  
Christopher D. Liman ◽  
...  
Keyword(s):  
Self Assembly ◽  
Low Cost ◽  
Ion Beam ◽  
Three Dimensional ◽  
Incident Beam ◽  
Residual Layer ◽  
Processing Conditions ◽  
Dimensional Metrology ◽  
Grid Pattern ◽  
X Ray

The directed self-assembly (DSA) of block copolymers (BCPs) is a promising low-cost approach to patterning structures with critical dimensions (CDs) which are smaller than can be achieved by traditional photolithography. The CD of contact holes can be reduced by assembling a cylindrical BCP inside a patterned template and utilizing the native size of the cylinder to dictate the reduced dimensions of the hole. This is a particularly promising application of the DSA technique, but in order for this technology to be realized there is a need for three-dimensional metrology of the internal structure of the patterned BCP in order to understand how template properties and processing conditions impact BCP assembly. This is a particularly challenging problem for traditional metrologies owing to the three-dimensional nature of the structure and the buried features. By utilizing small-angle X-ray scattering and changing the angle between the incident beam and sample we can reconstruct the three-dimensional shape profile of the empty template and the residual polymer after self-assembly and removal of one of the phases. A two-dimensional square grid pattern of the holes results in scattering in both in-plane directions, which is simplified by converting to a radial geometry. The shape is then determined by simulating the scattering from a model and iterating that model until the simulated and experimental scattering profiles show a satisfactory match. Samples with two different processing conditions are characterized in order to demonstrate the ability of the technique to evaluate critical features such as residual layer thickness and sidewall height. It was found that the samples had residual layer thicknesses of 15.9 ± 3.2 nm and 4.5 ± 2.2 nm, which were clearly distinguished between the two different DSA processes and in good agreement with focused ion beam scanning transmission electron microscopy (FIBSTEM) observations. The advantage of the X-ray measurements is that FIBSTEM characterizes around ten holes, while there are of the order of 800 000 holes illuminated by the X-ray beam.

Sign in / Sign up

Export Citation Format

Share Document