Sharif Digital Repository

Two new dioxomolybdenum(VI) complexes have been synthesized by the reaction of N,N'-bis(5-chlorosalicylidene)-2,2'-dimethyl-1,3-propanediamine and N,N'-bis(5-bromosalicylidene)-2,2'-dimethyl-1,3-propanediamine as Schiff base ligands with [Mo(O)2(acac)2] in methanolic solution.and their electronic structures have been investigaged theoretically. The Schiff base ligands H2L1 and H2L2 were prepared by reaction of 5-Chlorosalicylaldehyde and 5-Bromosalicylaldehyde with 2,2'-dimethyl-1,3-propanediamine, respectively. The result of these reactions, was two complexes of Mo(O)2L1 and Mo(O)2L2 .The compounds were characterized by elemental analyses (CHN), and 1HNMR and IR spectroscopic techniques.... 

The charge transfer interaction of two Schiff-bases 2,5-dichloro -bis(thiophen-2-ylmethylene)benzene-1,4-diamine and 2,5-dimethyl-bis(thiophen-2- ylmethylene) benzene-1,4-diamine as donors with I2 and TCNE ethylene as acceptors have been studied spectrophotometrically.
The formation constants and extinction coefficients of charge transfer complexes have been determined by graphical as well as iterative methods. From measurements at different temperatures the thermodynamic functions of the charge transfer complex formation have been studied. The temperature dependence of the K can be used for the determination of the thermodynamic reaction quantities (ΔG, ΔS, ΔH) for linear regression... 

The selective oxidation of sulfides to sulfoxides is an important method in organic synthesis because sulfoxides are useful synthetic intermediates for the construction of various chemically and biologically significant molecules. To date, the most important method of preparation involves the oxidation of sulfides. Various oxidizing agents are used for this purpose. Oxovanadium(IV)(Salen) and oxovanadium(V)(Salen)Cl were synthesised and screened in the vanadium-catalysed oxidation of sulfides to solfuxides with urea hydrogen peroxide(UHP) as terminal oxidant. Both complexes showed good activity and selectivity trough the catalytic reaction.characterized by elemental analyses, IR, 1H and 13C... 

In recent years, application of transition metal biphasic catalytic systems for different reactions is an area of intense research activity. Among these reactions, oxidation of sulfides to sulfoxides and sulfones due to their importance as an intermediate in synthesis of organic compounds is a center of interest. Also, the catalytic conversion of alcohols to the corresponding aldehydes or ketones is a fundamental transformation in both laboratory and industrial synthetic chemistry. From environmental perspectives, the development of new catalytic oxidation systems with molecular oxygen as green oxidant is particularly attractive. In recent years, ionic liquids have been extensively studied... 

In this project a new dioxovanadium (V) complex of Schiff base ligand N`-[1-(2-hydroxynaphthyl)methylene]-2-hydroxy benzohydrazide was synthesized and fully characterized. This complex is a pentacoordinate one in which the dioxo groups are in cis form. For synthesis of this complex, first, the intermediate compound 2-hydroxy benzohydrazide was synthesized from hydrazine and methyl salicylate and condensed with 2-hydroxynaphthaldehyde to give the Schiff base ligand (H2NBD). Then from reaction of ligand and ammonium vanadate in DMF in 65 ̊C, the NH4[VO2(NBD)] was prepared. This complex was fully characterized by UV, NMR and IR spectroscopies and it’s application as catalyst in sulfoxidation... 

Mammalian cardiac tissue lacks the ability to effectively self-regenerate following severe damage. The application of external therapeutic agents with strong mechanical properties is needed to restore its function. Even though conventional therapies have several challenges and limitations, injectable hydrogels, with minimally invasive, can significantly improve cardiac tissue regeneration. Extracellular matrices are the most appropriate biomaterials for synthesizing cardiac scaffolds. The human amniotic membrane obtained from the amniotic sac is a readily available, abundant, and inexpensive candidate that has been successfully utilized for the clinical treatment of cardiac diseases.... 

This study involved the synthesis, structural characterization and studies of gadolinium (III) hexaaza macrocyclic Schiff base complexes containing pyridine head and their decomposition in aqueous solution.There are many applications of lanthanide(III) macrocyclic complexes as medicine and in the biological systems, as magnetic resonance imaging (MRI) agents, and etc.These applications require that the Gd(III) complexes be resistant to gadolinium ion release under physiological conditions.
We considered planer macrocyclic ligands as a means to obtain highly stable complexes of Gd(III). Symmetric [2+2] Schiff base macrocyclic derived from 2,6-diacetylpyridine with amines would exhibit... 

Salicylaldehyde-amino acid Schiff base complexes are used as non-enzymatic models for the metal-pyridoxal (Vitamin B6) amino acid Schiff base systems which are key intermediates in many metabolic reactions of amino acids catalyzed by enzymes which require pyridoxal as a cofactor (transamination, decarboxylation, α and β elimination, racemization, etc.). In addition, complexes of amino acid Schiff bases are considered to constitute new kinds of potential anticancer, antitumor, antiradical and antibacterial reagents. On the other hand nuclear magnetic resonance imaging (MRI), has become a powerful tool for clinical diagnostics thanks to the development of a new class of pharmaceuticals... 

Schiff bases are used as prevalent ligands in coordination chemistry and are prepared easily. Their application as mild inhibitory agents for prevention of various steel’s corrosion in acidic solution has been proved. When their structure is altered, multi-purpose application for them is found. This property has led to a motive for research and study. In this study, electronic properties of a group of Schiff bases are investigated. The goal of this study is using quantum mechanics (QM) as a tool for specifying electronic properties of some of these bases. With respect to QM calculation which is done by density functional theory (DFT), their properties as inhibitory agents are studied. First,... 

The aim of this study at the outset is synthesis of ligands with the ability to bridge formation between two groups i.e. C60 and Cobalt Schiff base complex (CoSALEN). Hence, four Schiff base ligands with pyridine electron donor moiety in one side, and such electron donor moiety pyridine, phenol and aniline in another side were synthesized and characterized by elemental analysis, 13C¬NMR, 1HNMR and IR Spectroscopy. In next step the interaction of these Schiff base ligands with CoSALEN complex and Fullerene C60, in the mixture of two solvents, i.e. toluene/dimethylsulfoxide and benzene/methanol was explored separately by UV-Visible Spectroscopy and their kinetic studies were also undertaken... 

In recent years, burns and deep wounds that occur in various accidents are important reasons of death in the world. Therefore, the healing process of burn and full thickness of wounds due to late treatment has always been considered by physicians. Thus, the correct treatment and speed of healing of these types of wounds have always been studied. Many synthetic and natural materials have been used to treat wounds, which among them, hydrogels have received a great attention due to creating a moist environment for wounds and absorbing secretions. However, external mechanical stresses may degrade the therapeutic hydrogel. Recently, self-healing coating hydrogels have been designed and developed... 

The first part of this thesis describes the synthesis and characterization of several Mn, Fe and Mo complexes containing tridentate Schiff base and oxazoline ligands and their reactivities as catalysts in the oxidation of organic compounds like olefins and sulfides, as well. The crystal structures of newly prepared cis-dioxo-bis[2-(2′-hydroxyphenyl)-oxazolinato]molybdenum(VI), cis-[MoO2(phox)2] and (N-hydroxyphenyl-salicylidenamine)(acetylacetonato)ethanol iron(III), [FeIII(N-OPh-sal)(acac)EtOH] complexes have been described by X-ray crystallography. Due to the difficulties in the preparation of suitable single crystals of novel... 

Two new copper(II) complexes, [CuL2] and [Cu(phox)2], were synthesized by reaction of 1-((4-bromophenylimino)methyl)naphthalen-2-ol, HL, and 2-(2′-hydroxyphenyl)-2-oxazoline, Hphox, as ligands and copper(II) acetate mono-hydrate with the ratio 2:1 (ligand:metal), respectively. For characterization and structure determination of synthesized complexes, different techniques were performed such as FT-IR, elemental analyses (CHN), and X-ray crystallography. The geometry around Cu atom is almost square planar in both complexes. The catalytic activity of the complexes was evaluated in azide–alkyne cycloaddition reaction in water without need of any additional agent. The reaction conditions for the...