Mohamed M. El-bendary

Structure and applications of metal-organic framework based on cyanide and 3,5-dichloropyridine

The reaction of the aqueous/acetonitrile solutions of K3[Cu(CN)4] and 3,5-dichloropyridine (3,5-dClpy), in the presence of Me3SnCl affords a new metal-organic framework (MOF), (3)∞[(CuCN)2·(3,5-dClpy)2], 1. The structure of the MOF 1 was characterized by IR, UV-visible, TGA and X-ray single crystal analysis. The structure of MOF 1 consists of CuCN building blocks which are connected by CN group forming 1D-zig-zag chains. Each chain is bridged to another chain by hydrogen bonding organizing 2D-sheets. The structure of 1 is further close packed by hydrogen bonds, π-π stacking and lp-π interactions creating 3D-network. The emission spectra and the thermodynamic parameters from TGA of the MOF 1 were discussed. The MOF 1 was used as heterogeneous catalyst for the oxidative discoloration of methylene blue dye (MB) by dilute solution of hydrogen peroxide as oxidant. The in vitro cytotoxic activity has been evaluated against the human breast cancer cell lines MCF-7. The cytotoxic effect of the MOF 1 on the viability of MCF-7 cells was determined by MTT assay.

Silver(I) 3-D-supramolecular coordination frameworks constructed by the combination of coordination bonds and supramolecular interactions

Room temperature reactions of the ternary adducts of AgNO3, bipodal ligand [4,4′-bipyridine (4,4′-bpy) or trans-1,2-bis(4-pyridyl)ethylene (tbpe) or 1,2-bis(4-pyridyl)ethane (bpe)] and organic ligand [4-aminobenzoic acid (4-aba) or 4-hydroxybenzoic acid (4-hba) or terephthalate ion (tph)] afford new 3-D supramolecular coordination polymers (SCPs), namely, {[Ag(4,4′-bpy) · H2O](4-ab) · 2H2O} (1), {[Ag(tbpe)]0.5(4-hb) · 3H2O} (2), [Ag2(L)2 · (tph)] (L = 4,4′-bpy, tbpe) (3,4) and {[Ag2(bpe)2 · (tph)] · 2H2O} (5). The bipodal ligand coordinates to silver forming a 1-D cationic chain (A), while the organic ligand and solvent form a 1-D anionic chain (B) via hydrogen bonds. The chains construct layers which are connected via hydrogen bonds and π–π stacking forming a 3-D network structure. The presence of the carboxylate, amino and hydroxyl groups in the organic ligands significantly extend the dimensionality via hydrogen bonds. All the SCPs 1–5 exhibit strong luminescence.

The Influence of Copper–Copper Interaction on the Structure and Applications of a Metal–Organic Framework Based on Cyanide and 3-Chloropyridine

The structure of the new metal–organic framework, [(CuCN)2·(3-Clpy)], 1, was characterized by IR, UV–visible, TGA and X-ray single crystal analysis. The structure of 1 consists of CuCN building blocks, which are connected by CN group to form two different chains; one puckered chain with TP-3 geometry around Cu(1) and a linear Cu(2)(CN)2 chain. The two kinds of chains are bonded by cuprophilic interactions creating a 3D-network. The network structure of 1 is further close-backed by π–π stacking and hydrogen bonds. The electronic absorption and emission spectra as well as the thermodynamic parameters from TGA of the MOF 1 are discussed. MOF 1 was used as an effective heterogeneous catalyst for the oxidative discoloration of methylene blue dye by dilute solution of hydrogen peroxide as the oxidant. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to determine the in vitro antitumor activity of MOF 1 on human breast cancer cell line, MCF7.

New Coordination Complexes of Cd(II) and Co(II) with Ethyl Isonicotinate Used for Catalytic Degradation of Acid Blue 92 Dye

Colorless crystals of the coordination polymer (CP) [Cd(EIN)2(SCN)2], 1, and pink crystals of the coordination complex [Co(EIN)4(SCN)2], 2 were prepared by the reaction of metal nitrate salt with ethyl isonicotinate (EIN) and thiocyanate anion as bridged ligand. The structures of 1 and 2 were characterized by elemental analyses, electronic, FT-IR, 1H-NMR spectroscopy, thermal analysis and X-ray diffraction measurements. The structure of the CP 1 consists of cyclic (CdSCN)n building blocks which exhibit chair conformation creating 1D-chain decorated by the coordinated EIN on both sides. The network structure of 2 contains discrete units of [Co(SCN)2(EIN)4] connected by extensive H-bonds to form 1D-chain. The free ethyl carboxylate groups play the essential role in the formation of the H-bonds extending the structures of 1 and 2 to 3D-network. The catalytic behavior of 1 and 2 was utilized for degradation of acid blue 92 dye (AB-92). The kinetic data indicated that 1 and 2 are effective catalysts for degradation of AB-92 while irradiation enhances significantly the rate of degradation. Disodium salt of terephthalic acid photoluminescence probing technology was carried out to identify the reactive oxygen species. Moreover, the efficiency of recycled the catalysts and the mechanism of degradation of AB-92 dye were also investigated.

Cluster type molecule as novel corrosion inhibitor for steel in HCl solution

The MOF [Ag (qox) (4-hb)] 1, was obtained at room temperature by the reaction of AgNO3, quinoxaline (qox) and 4-hydroxy benzoate (4-hb). A cluster molecule containing two silver atoms, two qox and two 4-hb ligands is considered the basic building block of the structure of 1. 3D-network structure is created via H-bonds and π-π stacking. The MOF 1 was tested as corrosion inhibitor for carbon steel in 1 M HCl solution using potentiodynamic polarization and electrochemical impedance techniques (EIS). The polarization measurements indicated that the MOF 1 is of mixed type. The adsorption of MOF 1 obeyed Langmuir adsorption isotherm. The inhibition efficiency increased with increase in MOF 1 concentration but decreased with increase in temperature. The activation and thermodynamic parameters were calculated and discussed. Mechanism of inhibition is explained on the basis of molecular structure of the inhibitor.

Synthesis and Structure Characterizations of Coordination Polymers Based on Silver(I) and Nitrogen Donors

Yellow crystals of the coordination polymers (CP) [Ag(qox)NO3], 1 [Ag(pyzca)], 2 were obtained by the reaction of AgNO3, quinoxaline (qox) or pyrazinecarboxylic acid (pyzcaH), respectively. The crystal structure of 1 displays 1D-extended chain of [Ag(qox)]n with NO3 coordinated to every Ag atom. The 1D-chains of 1 are interconnected by strong hydrogen bonds, π–π stacking and short contacts developing two dimensional sheets containing channels. Furthermore, the overall packing arrangement of 1 results 3D topology with corrugated network. The Ag atom in 2 acquires tetrahedral geometry while each pyzca ligand provides three donor sites connected to three Ag atoms. The structure of CP 2 displays 1D-extended helical chain of [Ag(pyzca)]n. The 3D-packing of the CP 2 creates nanometer pores. The luminescence properties of 1 and 2 were discussed.

Synthesis, characterization, and biological activity of Cd(II) and Mn(II) coordination polymers based on pyridine-2,6-dicarboxylic acid

The coordination polymers (CPs) {[Cd(Pydc)(H2O)3] · PydcH2} (I) and [Mn(Pydc)(H2O)3] · PydcH2} (II) were obtained by the reaction of CdSO4 · 5H2O or MnCl2 · 4H2O with pyridine-2,6-dicarboxylic acid (PydcH2). The structures of the CPs I and II were characterized by IR, UV-Vis, TGA, and X-ray single crystal analysis (CIF files CCDC nos. 1417757 (I), 1417758 (II)). The network structures of I and II are constructed by an infinite number of discrete binuclear molecules and free PydcH2. The structures of the CPs I and II connected by the extensive H-bonds and π–π stacking, forming a 3D-network. The CPs I and II were screened to test their antimicrobial activities against different species of bacteria and fungi.

Simple modification in Hautmann neobladder to carry out left ureteroileal anastmosis without mobilization of the ureter

We describe a simple modification in Hautmann neobladder that involves an elongation of its left chimney to advance it through the pelvic mesocolon in order to reach the left ureter in its original place. This technique was carried out on 27 patients who had Hautmann pouch after radical cystectomy, and we reported the outcome and complications that occurred at the site of urteteroileal anastomosis in the first 3 years after surgery. The modification was applied easily without any perioperative complications that were related to this step in particular. During follow up of these cases, we lost three patients who died before the end of the third postoperative year. At a mean follow up of 41.3 ± 10.2 months, we have not detected any cases of stricture formation or ureteral recurrence at the sites of the ureteroileal anastmosis. There was only one patient who developed acute pyelonephritis (3.7%) as a result of reflux.

Structure, Characterizations and Corrosion Inhibition of New Coordination Polymer Based on Cadmium Azide and Nicotinate Ligand

Green crystals of the coordination polymer (CP) [CdN3(en)(n)], 1, was obtained by reaction of CdSO4 · 5H2O with ethyl nicotinate (en) in the presence of NaN3. The structure of the CP 1 was characterized by elemental analysis, IR, 1H-NMR, UV-Visible and X-ray single crystal analysis. The ORTEP plot of CP 1 consists of [(Cd)4(N3)4(en)4(n)4] structure exhibiting 14-atom V-shaped cyclic configuration, which contains 8-atoms ring [(Cd)4(N3)4]. The structure of CP 1 creates 1D-chain where the cyclic structures are connected by two nicotinate ligands (n). The chains are extended in three directions forming 3D-network structure via extensive H-bonds. The CP 1 was tested as corrosion inhibitor for copper in 1 M HCl solution using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The results of polarization indicated that CP 1 acts as mixed type inhibitor. Adsorption of CP 1 obeyed Langmuir adsorption isotherm. Effect of temperature on the corrosion process was studied and activation parameters were calculated and discussed. The results obtained from the two different electrochemical techniques are in good agreement.

A new metal-organic framework based on cadmium thiocyanate and 6-methylequinoline as corrosion inhibitor for copper in 1 M HCl solution

Faint green crystals of the metal organic framework (MOF) [Cd(SCN)2(6-mquin)2], 1, was obtained by the reaction of CdSO4.5H2O with 6-methylequinoline (6-mquin) in the presence of KSCN. 3Dnetwork structure was created via H-bonds and π–π stacking interactions. The structure of the MOF 1 was characterized by IR, 1H-NMR, UV-visible, TGA, and X-ray single crystal analysis. The structure of the MOF 1 consists of cyclic (CdSCN)n building blocks exhibiting chair conformation creating 1D-chain decorated by the coordinated 6-mquin on both sides. The 1D zig-zagchain is bonded to another chain by hydrogen bonds organizing these chains into a 2D layer. Furthermore, the 2D layers are interacted each other feathering three-3D metal organic framework containing cavities through face-to-face π···π interactions. The MOF 1 was tested as corrosion inhibitor for copper in 1 M HCl solution using potentiodynamic polarization and electrochemical impedance (EIS) techniques. Adsorption of the MOF 1 obeyed Langmuir adsorption isotherm. Effect of temperature on the corrosion process was studied and the activation parameters were calculated and discussed. The results obtained from the two different electrochemical techniques are in a good agreement.