Sharif Digital Repository

A combination of solid acids, including Oxone®, HIO3, H 5IO6, and polystyrenesulfonic acid and sodium nitrite, in the presence of wet SiO2 were used as an effective oxidizing agents for the oxidation of dihydropyridines to their corresponding pyridine derivatives under mild and heterogeneous conditions in good to excellent yields  

Sample preparation for non-target analysis is challenging due to the difficulty in the extraction of polar and non-polar analytes simultaneously. Most commercial solid sorbents lack the proper comprehensiveness for extraction of analytes with different physiochemical properties. A possible key is the combination of hydrophobic polymer and hydrophilic surface functional groups in solid based extraction methods in order to generate the susceptibility for retaining both polar and non-polar analytes. To pursue this goal, in this study, four polar groups including [sbnd]NH 2 , [sbnd]NO 2 , [sbnd]COOH, and [sbnd]COCH 3 were chemically bound to Amberlite XAD-4 substrate in order to prepare a... 

A novel sulfoxide containing bis(ether amine) monomer, 2,2'-sulfoxide- bis[4-methyl(2-trifluoromethyl)4-aminophenoxy) phenyl ether] (M2), was synthesized from the halogen displacement of 2-chloro-5-nitrobenzotrifluoride with dibenzosulfoxide (DH) in the presence of potassium carbonate, followed by catalytic reduction of bis(ether nitro) intermediate with Zinc/Ammonium chloride. A series of organic-soluble poly(ether amide)s (PA1-7) bearing sulfoxide and electronwithdrawing trifiuoromethyl group were synthesized from bis(ether amine) with various aromatic diacids (1-7) via a direct polycondensation with triphenyl phosphite and pyridine. The resulting polymers had inherent viscosities ranging... 

In the present work we obtained a series of NIR luminescent platinum(II) complexes with a pincer N^N^C ligand based on the conjugated {benzoimidazo[1,2-a]pyrazine} system with the [Pt(N^N^C)L]n+ structural motif (L = phosphine, alkynyl or pyridine-type ligands). We have also synthesized two complexes with bidentate phosphines that demonstrate different types of coordination: 1) as chelating ligand (in case of 1,2-bis(diphenylphosphino)benzene), that led to de-coordination of pyridine ring of N^N^C ligand and formation of a [Pt(N^C)dppb]+ complex; 2) as a bridging ligand (in case of bis(diphenylphosphino)methane) between two {Pt(N^N^C)} fragments in a dimeric complex of type... 

Activated clay is an inexpensive substance with massive utilization for removal of unsaturated compounds on an industrial scale. The performance of activated clay in removing such compounds heavily relies on the type of pristine raw clay and acids which are used during the activation process. In this work, olefins removal from aromatic streams is reported by activated clays with two different routes of clay activation. After preliminary tests of four different natural clays, the best clay was selected due to having enhanced swelling index, cation exchange capacity, higher surface area, and better suspension stability, among others. Having activated clay with hydrochloric acid and sulfuric... 

Reaction of the zwitterions generated from isoquinoline or pyridine and dialkyl acetylenedicarboxylate with tetronic acid leads to 1,2- dihydroisoquinoline or 1,2-dihydropyridine tetronic acid derivatives without using any catalyst or activation at room temperature  

Symmetrical and unsymmetrical biscyclometalated platinum(II) complexes [Pt(ptpy)2], 1, and [Pt(ptpy)(bppy)], 2, in which ptpy = deprotonated 2-(p-tolyl)pyridine and bppy = deprotonated 2-(3-bromophenyl)pyridine, have been prepared from the reaction between tris(pentafluorophenyl)borane, B(C6F5)3 and 1 equiv of monocyclometalated complexes [PtMe(ptpy)(ptpyH)], B, and [PtMe(ptpy)(bppyH)], C, respectively. The solid-state structures of 1 and 2 have been determined by X-ray crystallography. The reaction of 1 with 1 equiv of TlPF6 or [Au(PPh3)]OTF resulted in the production of heteronuclear complexes [Pt(ptpy)2Tl]PF6, 3 and {Pt(ptpy)2[Au(PPh3)]}OTF, 4, respectively. X-ray diffraction data showed... 

In the present work a pH responsive drug nanocarrier based on magnetic mesoporous silica nanoparticles (MMSN) and polyethylene glycol-co-polyvinyl pyridine (PEG-co-PVP) was prepared. The core-shell nanocarrier was formed due to electrostatic interaction between protonated polyvinyl pyridine and surface modified MMSN with carboxylate groups. This carrier was used for pH-controllable doxorubicin release. The maximum release was occurred at pH 5.5 (pH of endosomes). This carrier was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, UV-Vis spectrophotometer, scanning electron microscope, and high-resolution transmission electron microscope techniques. Also the... 

Site reactivity of some enol-imines derived from N-aryl formamides with pentachloropyridine under basic conditions in dry CH3CN was investigated. The aromatic nucleophilic substitution of pentachloropyridine with enol-imines occurs at the 4-position of pyridine ring by both oxygen and nitrogen site of enol-imines. Nucleophilic attack by the oxygen of enol-imine gave corresponding oximino compounds as a mixture of E- and Z-isomers. In contrast, nucleophilic attack by the nitrogen of enol-imine gave the unexpected N,N-di-substituted aryl compounds. The structures of all the compounds were confirmed by IR, 1H NMR, 13C NMR and 19F NMR spectroscopy as well as elemental analysis and...