Safaa El-din H. Etaiw

Synthesis, spectral, antimicrobial and antitumor assessment of Schiff base derived from 2-aminobenzothiazole and its transition metal complexes

N-(thiophen-2-ylmethylene)benzo[d]thiazol-2-amine Schiff base (L) derived from 2-aminobenzothiazole and 2-thiophenecarboxaldehyde was synthesized and characterized using elemental analysis, IR, mass spectra, (1)H NMR and UV-vis spectra. Its complexes with Cu(II), Fe(III), Ni(II) and Zn(II) were prepared and isolated as solid products and characterized by elemental and thermal analyses, spectral techniques as well as magnetic susceptibility. The IR spectra showed that the Schiff base under investigation behaves as bidentate ligand. The UV-vis spectra and magnetic moment data suggested octahedral geometry around Cu(II) and Fe(III) and tetrahedral geometry around Ni(II) and Zn(II). In view of the biological activity of the Schiff base and its complexes, it has been observed that the antimicrobial activity of the Schiff base increased on complexation with the metal ion. In vitro antitumor activity assayed against five human tumor cell lines furnished the significant toxicities of the Schiff base and its complexes.

A novel hydrogen bonded bimetallic supramolecular coordination polymer {[SnMe3(bpe)][Ag(CN)2] · 2H2O} as anticancer drug.

The reaction of Me(3)SnCl, K(3)[Ag(CN)(4)] and 1,2-bis(4-pyridyl)ethane (bpe) in water/CH(3)CN solution at room temperature affords the novel bimetallic supramolecular coordination polymer (SCP) {[SnMe(3)(bpe)] [Ag(CN)2] · 2H(2)O}(n), 1. The structure of 1 consists of cationic {-Sn(Me(3))-bpe-}(+) chains that are neutralized by [Ag(CN)(2)](-) anions. The dicyanoargentate(I) anions present discrete uncoordinated fragments between the cationic chains. The water molecules bind the cationic chains and the anions forming 3D-supramolecular structure through hydrogen bonds. 1 exhibits strong fluorescence in the solid state at room temperature. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to determine the in vitro antitumor effects of the SCP 1 on human breast cancer cell line, T-47D. Cell cycle analysis revealed that the SCP 1 induced apoptosis in T-47D breast cancer cell line. Moreover, in vivo, the SCP 1 showed tumor growth inhibition in rat model that developed mammary carcinoma by 44.8% compared to the vehicle treated control. Thus, the SCP 1 exhibits specific in vivo and in vitro antitumor effects.

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.

Fluorescence decay of singlet excited-state of safranine T and its interaction with ground-state of pyridinthiones in micelles and homogeneous media.

The fluorescence decays of safranine T were studied in different homogeneous solvents and heterogeneous micellar solutions. It has been found that micellization leads to an increase in the lifetime. The lifetime distributions were studied in micelles and homogeneous media. It was found that the different half-width distributions of the dye in different micelles are related to the different orientation of the dye in different micelles. Also, the fluorescence quenching of safranine T by 4,6-disubstituted-3-cyanopyridin-2(1H)-thiones was studied in chloroform, methanol and acetonitrile as well as in different micelles. In heterogeneous media the kq values for quenching of safranine T by thiones in various micelles increase on the following order: kq(CTAB) < kq(TX-100) < kq(SDS). This is due to the electrostatic interactions between the anionic SDS and the cationic moiety of safranine T and therefore the quenching process will be less significant.

Preferential solvation of solvatochromic benzothiazolinic merocyanines in mixed binary solvents

Abstract The preferential solvation of α- and γ-oxobenzothiazolinic merocyanines was studied using UV-visible spectroscopy in binary solvent mixtures containing either water or methanol and cosolvents (formamide, ethanol, 2-propanol, DMF, CH3CN and 1,4-dioxane). In binary mixtures containing water, the dyes are preferentially solvated by the organic cosolvent over the whole composition range, only in the case of the α-oxo derivative in H2O–CH3CN mixtures the solvatochromic plot showed a biphasic behavior. In binary solvent mixtures comprising MeOH, the dyes showed no preference for either solvents in MeOH–EtOH mixtures, while in MeOH–CH3CN and 1,4-dioxane–MeOH mixtures the former solvent was the preferred one. Also, the results showed that γ-oxo derivative is preferentially solvated by the cosolvent in both MeOH-2-propanol and MeOH–DMF mixtures. Although the α-oxo analogue showed an ideal behavior in MeOH-2-propanol mixtures as well as in the MeOH rich region in MeOH–DMF mixtures, it is solvated preferentially by MeOH in the DMF rich side. Also, the role of solute-solvent and solvent-solvent interactions in determining the preferential solvation was discussed.

Metal complexes with Alizarin complexone—I: Physiocochemical characters and stability constants of the Sc3+, Y3+, La3+, Ce3+, Gd3+ and Yb3+ complexes

Complexes of Alizarin complexone with Sc3+, Y3+, La3+, Gd3+, Ce2+ and Yb3+ have been synthesized and characterized by, pH titrations, conductance measurements, UV, visible and IR spectral studies.

The organotin coordination polymer [(n-Bu3Sn)4Fe(CN)6H2O] as effective catalyst towards the oxidative degradation of methylene blue

The structure of the supramolecular coordination polymer SCP 1; [(n-Bu3Sn)4Fe(CN)6H2O] consists of octahedral [Fe(CN)6](4-) building blocks which are connected by the TBPY-5 configured n-Bu3Sn(CN..)2 fragments creating 3D-network structure. Fenton and photo-Fenton oxidative discoloration of Methylene Blue (MB) has been investigated by hydrogen peroxide catalyzed with the SCP 1. The reaction exhibited pseudo first-order kinetics with respect to each of MB and H2O2. The irradiation of the reaction with UV-light enhanced the rate of MB mineralization, Kobs=0.76 h(-1). Mineralization of MB was investigated by FT-IR spectra. Disodium salt of terephthalic acid photoluminescence probing technology was carried out to identify the reactive oxygen species. The different parameters that affect MB degradation rate were evaluated. Moreover, the efficiency of recycled the SCP 1 and the mechanism of degradation of MB dye were investigated.

In-situ intercalative oxidation of some pyridine derivatives within the cavity of the three-dimensional polymeric host [(Me3Pb)3Fe(CN)6]∞

Abstract Pyridine derivatives acting as guest species can be oxidized by the three-dimensional polymeric host [(Me 3 Pb) 3 Fe(CN) 6 ] ∞ forming yellow to brown or red colored CT complexes depending on the degree of charge transfer. The donor molecules can be intercalated within the cavity of the polymeric host in a 1/1 ratio after completion of the reaction. The CT complexes are weak semiconductors under the experimental conditions used.

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.