Journal of Physical and Theoretical Chemistry
Volume:7 Issue: 1, Spring 2010

Polychlorinated Biphenyls (PCBs) have been widely used to flame-retard products common in homes and theworkplace, and subsequently. Polychlorinated biphenyls (PCBs) typify a class of highly toxic, stable aromaticpollutants. PCBs are recently being scrutinized for potential environment damage in groundwater and in theatmosphere. The elimination of chemical pollutants from a contaminated environment is one of the roostimportant steps towards achieving the goal of environmental remediation.Recent studies have used carbon mnombes (CNTs) for adsorption of pollution in environment, which aresignificantly higher dioxin elimination efficiencies In this study, mechanism and interaction of single-walledcarbon naotube (SWNT) for removal of PCBs are calculated by Gaussian program package. Inter SWNT; therearc four situations for PCBs near SWNT (6, 6) with length of 1.54 um that we calculated simulation of passingPCB through SWNT. The thermodynamics properties are calculated for passing PCBs across from SWNT thattheir results are showed this method can use for removal PCBs in environmental and their interaction are lowpotential in SWNT middle. So there is a place for adsorption of PCBs into SWNT, PCBs trap in it This passingis exothermic, spontaneous, and favorable.

The DO1(18c6)fi (MwLi. Na. K and I 8c6=18-crown-6) complexes have been chosen as the model systems toinvestigate the nature of chemical bonds between alkali metal cations and large mffitidentaie orgmnic ligands.The B3LYP/6-3I+G(d,p) level of calculation has been used for obtaining equilibrium geernetnes and p(r)functions (electron density distributions). By the aid of fundamental physical theorems implemented inQuantum Theory of Atoms in Molecules (QTAINA), the structures and the physical nature of chemical bondshose been determined for cited species at the mentioned theoretical level. These results establish the metaloxygenin all complexes in this work as ionic. The Li+ shows the coordination number of 3 with Igen crownether and Na and rexhibits the coordination number of 6.

Nowadays apphcanon of nanotubes in biology and medicinal science is more investigated. Nanotubes can passthroueh cell walls and transport and release drugs in special tissues. The purpose of this paper is to investigatethe interaction of a nanotube having hydroxyl functional groups (OH) with an anticancer agent. In this worktransporting of an anticancer drug named 2-(2-amino 6,7-dimethyl Pteridine 4-ylammo)-ethanol by a zigzagnanotube with 60 C atoms (5,0) is investigated. The methods used are quantum mechanics and seroiemphical.Two composites of the drug and nanotube are under studying: I-compose of drug and nanotubes wall 2-compose of drug and one of the two heads of nanombe. At first some hydroxylic functional groups are put onthe head of nanotube and then an etheric bond formed between agents. The results show that the composite ismore stable than the single agent. Also binding of drug with the head of the nanotube is more stable than thewall. In the other case the Interaction between a carbon nanotube (9,0) and Levothyroxine as a drug isinvestigated. All of above composites art investigated by semiempincal methods and MolecularMechanicsiMolecular Ilymunics simulation in body temperature (310 K) and their heat capacities are obtainedin water, methanol and ethanol solutions separately. The results show that by increasing initial temperature inmost of the cases heat capacity increase& Also it can be seen that by increasing of solvent molecular mass, theheat capacity increases too.

Energy gaps, AXsar (X=E, H and G) (AX.,.,-=lia,„,,,InrX“dpka,) between single (s) and triplet (I) states werecalculated at B3LTP/6-3 I 1.HO" level of theory. Our results showed that electron donating substituents(G = -NHz, -OH. -CH), -F, -Cl and -Br) at phenyl group cause to increase and electron withdrawingsubstiluents (G -CF2. and -NO:) lead to decrease the singlet-triplet energy gaps of Ar - Cana CT

Diminishing protein aggregation by chaperone is very important factor in medicine and industry. In this paper, itis induced the chaperone ability for 0-casein upon modification of its acidic residues by Woodward reagentK(WRK) and examined on lysozyme as a target protein at pH 7.2 and outlined the mechanism for chaperoneability of modified system by UV-Vis and fluorescence spectroscopy and theoretical calculation methods.

The dried nitrate-urea gels exhibit the combination of autoicatatric combustion behavior and ultrasonic, whichcan be used to synthesize the nanocatalyst ferrite powders. Cu and Ni Unites nanocatalyst powders sithcomposition of Caned], and NiFe204 were synthesized by a sol-gel auto catalnic combustion process. Themolar ratio between metal ions and urea was 11.2. The sob gel process was done at 80 °C. The nanopaniclecrystallines have been calcined at 800 °C.Combustion behavior and crystallite size of synthesized powders were investigated iyith the help of ScanningElectron Microscopy observation and X-ray diffraction technique. X- ray diffraction and Scanning ElectronMicroscopy were carried out for charactenzation of the powders. The grain size of the prepared femte powdersis found lobe in the range 30-35 mu_

Plane-wave pseudopotential Density Functional Theory (OFT) periodic slab calculations were performed usingthe giteralized gradient approximation (GHA) to investigate the adsorption of nitric oxide(NO) on the (I II)surface of Cu. Copper rface was stimulated using th P 'odic Slab Method consisting of Five atomic Layers.Four different adsorption saes (Atop. Bridge, RCP Hollow, and FCC Hollow) were considered. Resultsspecified that the suitable site for NO adsorption in molecular foun is the Hollow FCC site, and molecularadsorption is more stable than dissociative adsorpnon energetically.

We optimized the geometries of the graphene and graphene with hydrogen using PW91VWN, PWCIPL,MPWLYP, G96LYP, G96141.0-210.6-310, 6-31G*Ievels of theory and compared our results with each other.We present the most important structural parameters determined for the addition of a hydrogen atom tographene and the outward movement of the carbon atom that is bonded to hydrogen is 0.48 A Also wecalculateed vibrational frequencies at the same levels. All thenned)mamic parameters of including AG, H. ASwere calculated

The catalyst Pt-Ta supported on 7-alumina was prepared by impregnation with solution containing compoundsof II21K1.0. and Ta205 The Pt concentration was kept constant at 0.2 vet% while the concentration of thetantalum was 0,4 wt%. The activity and selectivity of catalyst were determined under conditions at 450-500 °Cand 15-30 atm.. with molar ratio H2/C[H,e5 and WH=1.5mL/h for converted n-heptane. The results showedthat in the presence the catalyst is stable and has much higher selectivity for aromatization reaction. It wasshovm that Ta modifies the acidity of support, resulting to higher selectivity for eternalization, and modifies theproperties of the Pt catalyst.

As drug delivery systems Nanoparticulan widely investigated because of many advantages such as smaller size,controlled drug release potentiaL targeting ability, enhancement of therapeutic efficacy and reduction oftoxicity. So, carbon nanotubes have recently received considerable attention as alternative drug delivery carrierIn this study we investigate interaction of tamoxifen with open-end of shgle-walled carbon nanotubes (SWNTs)using the Gaussian 98 program. We have computed NMR shielding tensors at BILTP and HF levels by using 3-21G and 570-36 basis sets in the water. Our results reveal that NMR chemical shielding parameters arestrongly affected by inducing solvent media. Regarding to our plotted graph f pp, do, , 8 in differentmethods and basis sets, the largest crw values obtained for Op atom at the 11F in STO-30 whereas the smallestone belonged to Cp. It is interestusg to note that the opposite trend have been observed for asymmetryparameterseaL