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Institute for Advanced Studies in Basic Sciences (IASBS)

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Department of Chemistry
Elham Safaei  
Associate Professor
Room: chemistry Building 200
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1- Safaei, E., Hajikhan Mirzaei, L., karimi, B., Wojtczak, A., Cotic, P., Lee, Y. I., "TEMPO-mediated aerobic oxidation of alcohols using copper(II) complex of bis(phenol) di-amine ligand as biomimetic model for Galactose oxidase enzyme", Polyhedron, 106, 153-162, (2016).

Mononuclear copper complexes of four-dentate N2O2 bis(phenol) diamine ligands (H2LNEX X: C and OB in which C and OB are chloro and tert-butyl-methoxy substituents on phenol groups) have been synthesized and characterized by IR, UV–Vis, single crystal X-ray diffraction, magnetic susceptibility studies and cyclic voltammetry techniques. The CuLNEX complexes show the square pyramid geometry of the coordination sphere with the copper centers surrounded by two nitrogen and oxygen atoms from the coordinating ligand and an axially bound water molecule. The effective magnetic moments of 1.7 and 1.8 BM confirm a monomer complex with copper(II) center. Electrochemical oxidation of these complexes yielded the corresponding Cu(II)-phenoxyl radical species. In addition, CuLNEX complexes, have shown efficient catalytic activities for TEMPO-mediated oxidation of a set of alcohols to the corresponding aldehydes in the presence of molecular oxygen as oxidant at room temperature.
2- Hassani , L., Fazeli , Z., Safaei, E., Rastegar , H., Akbari, M., "A spectroscopic investigation of the interaction between c-MYC DNA and tetrapyridinoporphyrazinatozinc(II)", Journal of Biological Physics, 40, 275-283 , (2014).

The c-MYC gene plays an important role in the regulation of cell proliferation and growth and it is overexpressed in a wide variety of human cancers. Around 90% of c-MYC transcription is controlled by the nuclease-hypersensitive element III1 (NHE III1), whose 27-nt purine-rich strand has the ability to form a G-quadruplex structure under physiological conditions. Therefore, c-MYC DNA is an attractive target for drug design, especially for cancer chemotherapy. Here, the interaction of water-soluble tetrapyridinoporphyrazinatozinc(II) with 27-nt G-rich strand (G/c-MYC), its equimolar mixture with the complementary sequence (GC/c-MYC) and related C-rich oligonucleotide (C/c-MYC) is investigated. Circular dichroism (CD) measurements of the G-rich 27-mer oligonucleotide in 150 mM KCl, pH 7 demonstrate a spectral signature consistent with parallel G-quadruplex DNA. Furthermore, the CD spectrum of the GC rich oligonucleotide shows characteristics of both duplex and quadruplex structures. Absorption spectroscopy implies that the complex binding of G/c-MYC and GC/c-MYC is a two-step process; in the first step, a very small red shift and hypochromicity and in the second step, a large red shift and hyperchromicity are observed in the Q band. Emission spectra of zinc porphyrazine are quenched upon addition of three types of DNA. According to the results of spectroscopy, it can be concluded the dominant binding mode is probably, outside binding and end stacking.
3- Hassani, L., Hakimian, F., Safaei, E., "Spectroscopic investigation on the interaction of copper porphyrazines and phthalocyanine with human telomeric G-quadruplex DNA", Biophys. Chem, 187, 7-13, (2014).

The G-quadruplex DNA is a novel target for anticancer drug discovery and many scientific groups are investigating interaction of small molecules with G-quadruplex DNA to discover therapeutic agents for cancer. Here, interaction of a phthalocyanine (Cu(PcTs)) and two tetrapyridinoporphyrazines ([Cu(2,3-tmtppa)]4+ and [Cu(3,4-tmtppa)]4+) with Na+ and K+ forms of human telomeric G-quadruplex DNA has been investigated by spectroscopic techniques. The results indicated that interaction of the cationic porphyrazines is remarkably stronger than the anionic phthalocyanine and they presumably bind to the G-quadruplex DNA through end-stacking. Fluorescent intercalator displacement assay implied the displacement ability of the complexes with thiazole orange. In addition, circular dichroism spectra of both quadruplex forms converge to the Na+ isoform after binding to the porphyrazines. In conclusion, the porphyrazines as the complexes that bind to the G-quadruplex DNA, could be suitable candidates for further investigations about inhibition of telomerase enzyme.
4- Sheykhi, H., Safaei, E., "A proline-based aminophenol ligand: Synthesis, iron complexation, magnetic, electronic and redox investigation", Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy , 118, 915-920, (2014).

A new proline-based aminophenol ligand was synthesized by a convenient procedure. The ligand was characterized by 1H NMR, 13C NMR and IR spectroscopies, elemental analysis and optical activity measurements. Mononuclear iron(III) complex (FeLPro) of this ligand was synthesized and characterized by IR, UV–vis, ESI-MS, magnetic susceptibility studies and cyclic voltammetry techniques. The equilibrium formation constant of FeLPro and the pure UV–vis spectral profile of the complex was determined by multivariate hard modeling method. The molecular structure of FeLPro determined by ESI-MS consist of two aminophenolate ligands. The variation of magnetic susceptibility with temperature indicates paramagnetic iron(III) in the monomeric complex. FeLPro complex undergo metal-centered reduction, and ligand-centered oxidation.
5- Hassani , L., Hakimian, F., Safaei, E., Fazeli, Z., "Antibacterial effect of cationic porphyrazines and anionic phthalocyanine and their interaction with plasmid DNA", J. Mol. Struct, 1052, 221-227, (2013).

Resistance to antibiotics is a public health issue and identification of new antibacterial agents is one of the most important goals of pharmacological research. Among the novel developed antibacterial agents, porphyrin complexes and their derivatives are ideal candidates for use in medical applications. Phthalocyanines differ from porphyrins by having nitrogen atoms link the individual pyrrol units. The aza analogues of the phthalocyanines (azaPcs) such as tetramethylmetalloporphyrazines are heterocyclic Pc analogues. In this investigation, interaction of an anionic phthalocyanine (Cu(PcTs)) and two cationic tetrapyridinoporphyrazines including [Cu(2,3-tmtppa)]4+ and [Cu(3,4-tmtppa)]4+ complexes with plasmid DNA was studied using spectroscopic and gel electrophoresis methods. In addition, antibacterial effect of the complexes against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria was investigated using dilution test method. The results indicated that both porphyrazines have significant antibacterial properties, but Cu(PcTs) has weak antibacterial effect. Compairing the binding of the phthalocyanine and the porphyrazines to DNA demonstrated that the interaction of cationic porphyrazines is stronger than the anionic phthalocyanine remarkably. The extent of hypochromicity and red shift of absorption spectra indicated preferential intercalation of the two porphyrazine into the base pairs of DNA helix. Gel electrophoresis result implied Cu(2,3-tmtppa) and Cu(3,4-tmtppa) are able to perform cleavage of the plasmid DNA. Consequently, DNA binding and cleavage might be one of the antibacterial mechanisms of the complexes.
1- Dolatyari, V., Safaei, E., Karimi, B., "Synthesis and Characterization of Mn(II) and Pd(II) Complexes of Bis(Picolylamine) and Bis(Phenol) amine Ligands Supportedon Ordered Mesoporous Silica (SBA-15)", 17th Iranian Inorganic Chemistry Conference, Azarbaijan Shahid Madani University, 3-5 Sep 2015, Tabriz, Iran, 143-, (2015).

In coordination chemistry, various ligands are used to modulate the electronic and steric properties of the metalion and consequently the reactivity of metal species. As homogeneous catalysts are mostly often difficult to separate forreuse after reactions, the immobilization of a homogeneous catalyst onto a solid surface is one of the major challenges in catalysis chemistry. By loading these complexes onto mesoporous materials, one can achieve fixed homogeneous catalysts, which facilitates the separation and reuse of valuable catalysts, able to reduce both envieonmental pollutions and material costs. Covalent bond grafting os one of the most important strategies which have been developed for loading of such molecular catalysts. In our work, new Mn(II) complex of bis(phenol)amine ligand and Pd(II)complex of bis(picolyl amine) ligand supported on functionalized SBA-15 were synthesized. The precursor and supported complexes were characterized by different techniques such as: FT-IR, TGA, SEM, TEM, EDX, XRD, ICP, CHN and porosimetry. All results confirmed the successful anchoring of complexes onto the functionalized SBA-15 by covalent bonding
2- Dolatyari, V., Safaei, E., Karimi, B., "Synthesis and Characterization of Bis(phenol) amineLigand Supported on SBA-15 and Investigation of the Catalytic Activity of its Mo Complex in Sulfide Oxidation Reaction", 17th Iranian Inorganic Chemistry Conference, Azarbaijan Shahid Madani University, 3-5 Sep 2015, Tabriz, Iran, 145-, (2015).

Supported metal complexes have received a great deal of attention in recent years due to their catalyst enhancement and recyclability. One of the most important ways of heterogenization of metal complexesis their immobilization on insoluble ordered mesoporous silica which provides an elegant solution to the separation and recovery of catalysts. Among this group, complexes supported on SBA-15 have a unique place in catalyst chemistry. In the recent work, a novel molybdenum based catalyst, MoLGDC-AP@SBA-15 has been synthesized by covalent grafling of bis(phenol)amine ligand with chlorine substituent on the functionalized ordered mesoporous silica (SBA-15) followed by complexation with molybdenumsalt. The catalyst was characterized by FT-IR, TGA, SEM, TEM, EDX, XRD, ICP, CHN. Oxidation of sufides to corresponding sulfones or sulffxides, in solvent-free conditionor ethanol as a solvent was carried out respectively. The interesting features of this catalytic system include high selectivity, low reaction time, high yield and the efficient use of hydrogen peroxide as a cheap, environmental friendly and readily available oxidant under mild condition (room temperature). The recycling experiment results showed that MoLGDC-AP@SBA-15 could be easily recovered and recycled for four times without loss of the activity and selectivity.
3- Safaei, E., Karimpour, T., Karimi, B., "Immobilization of new iron complex supported on silica coated magnetic Fe3O4 nanoparticles: Magnetically recyclable catalyst systems for the high selective oxidation of sulfides ", 17th Iranian Inorganic Chemistry Conference, Azarbaijan Shahid Madani University, 3-5 Sep 2015, Tabriz, Iran, 248-, (2015).

Recoverable catalysts have attracted a great deal of interest in both academic and industrial research because, in addition to environmental concerns, there are beneficial effects of decreasing the cost of the final product. Immobilization of the catalytically active molecules onto the surface of magnetic nanoparticles is a suitable way to separatethe catalyst from the reaction mixture. Herein we have synthesized a new magnetically separable catalyst consisting of iron complex supported by amine-bis (phenolate) ligand, covalently supported onsilica-coated Fe3O4 nanoparticles. The mentioned catalyst characterized by thermo gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), scanningelectron microscopy (SEM), Transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM) techniques. Our synthesized catalyst with iron centor could be particularly attractive because of readyavailability, low cost and low toxicity of this metal. This catalyst exhibited high catalytic activity in selective oxidation of of aromatic and aliphatic sulfides with H2O2 Interestingly, the novel catalyst could be recovered in a facile manner from the reaction mixture by applying an external magnetic field without any significant loss in activity
4- Safaei, E., Saberikia, I., Karimi, B., "Molybdenum(VI)complex bearingmono(phenol)amine anchored SBA-15: Anovelheterogeneous catalyst for the oxidation of organic sulfides", 17th Iranian Inorganic Chemistry Conference, Azarbaijan Shahid Madani University, 3-5 Sep 2015, Tabriz, Iran, 307-, (2015).

Oxidation of sufides into their corresponding sulfoxides and sulfonesis one of the most important processes from both laboratory and industrial point of view due to their role as intermediates for the synthesis of chemically and biologically significant molecules. Nowadays, various catalytic systems based on metal complexes for the oxidation of sulfides have been reported. In this research, an efficient molybdenum based catalyst has been synthesized by covalent grafting of (R)-1-(3,5-dichloro-2-hydroxybensyl) pyrrolidine-2-carboxylic acid onto functionalized ordered mesoporous silica (SBA-15) followed by complexation with molybdenum salt. The catalyst was characterized by TEM, BET surface area analysis, FT-IR, atomic absorption spectroscopy and TGA analysis. The synthesized catalyst was found to be highly efficient, easy reusable for oxidation of various sulfides to their corresponding sulfones in the presence of aqueous 25%H2O2 at room temperature and solvent free conditions. Furthermore, the oxidation of dibenzothiophene (DBT) as one of the most important pollutant fuels by this catalyst gave an overall yield of dibenzothiophenesulfone
5- Safaei, E., Saberikia, I., Karimi, B., "Aminophenolate copper based complex grafting on to functionalized ordered mesoporous silica (SBA-15) for the aerobic oxidation of benzylic alcohols", 17th Iranian Inorganic Chemistry Conference, Azarbaijan Shahid Madani University, 3-5 Sep 2015, Tabriz, Iran, 308-, (2015).

Aerobic oxidation of alcohols to the corresponding carbonyl compounds has received increas in gattention in organic synthesis. Copper would seem to be a suitable active catalyst for this transformation with dioxygen in laboratory similar to that occurs at a wide variety of copper enzymes active sites., e.g. galactose oxidase, which catalyze this conversion in vivo. Therefore, copper complexes have attracted significant attention for the catalytic aerobic oxidation of alcohols in recent years, In this study, a novel copper based catalyst has been synthesized by covalent grafting of (R)-1-(3,5-dichloro-2-hydroxybenzyl)pyrrolidine-2-carboxylic acid ligand onto functionalized ordered mesoporous silica (SBA-15) followed by complexation with copper(II) acetate. The catalyst was characterized by TEM and BET surface area analysis, FT-IR, atomic absorption spectroscopy and TGA analysis. The immobilized catalyst was employed for the catalytic aerobic oxidation of benzylicalcohols to the corresponding aldehydes using TEMPO as co-catalyst. Moreover, this catalyst could be easily recovered by simple filtration and recycled for six times without loss of activity and selectivity
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