Molecular Structure,Electronic Properties,Homo–Lumo,MEP and NBO Analysis of (N-Isocyanimino) Triphenylphosphorane (Ph3PNNC): DFT Calculations

Journal of Structural Chemistry - N-isocyaniminotriphenylphosphorane (Ph3PNNC) is a type of iminophosphorane which is an important reagent in synthetic organic chemistry and a ligand in metallic...     

QUALITATIVE STUDIES OF THE LOW TEMPERATURE PHOTOCHEMISTRY OF RHODOPSIN AND RELATED PIGMENTS

Abstract— Rhodopsin, the isomeric pigments formed from 9- cis - and 9, 13- dicis -retinal, and the synthetic pigments formed from 9- cis - and 11- cis -14-methylretinal were irradiated with 490 nm light at -196C. Absorption spectral changes indicate that a distinguishable bathorhodopsin type intermediate may be formed for each pigment. The bathorhodopsin intermediates of the 9- cis pigments have band maxima hypsochromically shifted by4–5 nm compared to their corresponding rhodopsins. The bathorhodopsin type intermediate formed upon irradiation of 9, 13- dicis -rhodopsin has an absorption that maximizes 6 nm shorter than that of rhodopsin. Band maxima of the bathorhodopsin intermediates of the 14-methylrhodopsins are bathochromatically shifted ca. 8 nm compared to their corresponding rhodopsins.     

Hydrothermal synthesis of a nano-rod mercury(ii) metal-ligand coordination compound

A novel nano-rod mercury(II) coordination compound [Hg (BINH)I₂] (1), (BINH is the abbreviation of benzylideneisonicotinohydrazide) is synthesized by a hydrothermal method that produces the coordination compound at a nanosize level. The new nanostructure is characterized by scanning electron microscopy, powder X-ray diffraction, elemental analysis, and IR spectroscopy. Compound 1 was structurally characterized by single crystal X-ray diffraction and the single-crystal structure of this complex shows that each mercury(II) center is four-coordinated with two N-donor atoms from tow BINH ligands and tow iodo anions. Self-assembly of this complexes is pereformed by CH?I and π-π stacking interactions. The supramolecular features in these complexes are controlled by weak directional intermolecular interactions.     

Hydrothermal synthesis and characterization of Nd-doped ZnSe nanoparticles with enhanced visible light photocatalytic activity

In the present study, Nd³⁺-doped ZnSe nanoparticles with variable Nd contents were successfully synthesized via a hydrothermal process using Neodymium (III) chloride hexahydrate as the doping source. X-ray diffraction, UV–Vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy and transmission electron microscopy were used for characterization of the synthesized nanoparticles. It was confirmed by the DRS analysis that both of the undoped and Nd-doped ZnSe samples had significant optical absorption in the visible light range. The photocatalytic performance of as-synthesized nanoparticles was investigated towards the decolorization of C. I. Acid Orange 7 solution under visible light irradiation. Results indicated that the loading of Nd dopant into ZnSe nanoparticles significantly enhanced the photocatalytic activity of pure ZnSe with increasing Nd loading up to 6 mol% (color removal efficiency of 24.31 % for ZnSe and 84.20 % for Nd_0.06Zn_0.94Se after 120 min of treatment) and then the photocatalytic activity began to decrease.     

Modeling and optimization of simultaneous photocatalysis of three dyes on ceramic-coated TiO2 nanoparticles using chemometrics methods: phytotoxicological assessment during degradation process

In this paper, ceramic plates were used as a support of TiO₂ nanoparticles for photocatalytic decolorization of a mixture of three dyes. The three textile dyes (C.I. Basic Red 46, C.I. Basic Blue 3 and Malachite Green) were quantified simultaneously during the photocatalytic degradation process. The partial least squares modeling was successfully applied for the multivariate calibration of the spectrophotometric data. Also, the central composite design has been applied to the optimization of photocatalytic decolorization of the dye solution containing three dyes using an immobilized UV/TiO₂ process. The optimum initial concentration of three dyes, reaction time, and UV light intensity were found to be 5 mg/L, 240 min, and 47.2 W/m², respectively. The chronic phytotoxicity of mixture of dyes was evaluated using aquatic species Spirodela polyrhiza (S. polyrhiza) prior to and after photocatalysis. The phytotoxicity results revealed that the photocatalysis process could effectively reduce the phytotoxicity of the dyes from their aqueous solutions.     

Synthesis and structural characterization of three dinuclear Copper(II) complexes incorporating pyrazolyl-derived ligands

Three new binuclear copper complexes of formulae $ \left[ {{\text{Cu}}_{2}^{\text{II}} {\text{Pz}}_{2}^{\text{Me3}} {\text{Br}}_{ 2} \left( {{\text{PPh}}_{ 3} } \right)_{ 2} } \right] $ (1), $ \left[ {{\text{Cu}}_{ 2}^{\text{II}} {\text{Pz}}_{2}^{\text{Ph2Me}} {\text{Cl}}_{ 2} \left( {{\text{PPh}}_{ 3} } \right)_{ 2} } \right] $ (2) and $ \left[ {{\text{Cu}}_{2}^{\text{II}} \left( {{\text{Pz}}^{\text{PhMe}} } \right)_{ 4} {\text{Cl}}_{ 4} } \right] $ (3) (Pz^Me3?=?3,4,5-trimethylpyrazole, Pz^Ph2Me?=?4-methyl-3,5-diphenylpyrazole and Pz^PhMe?=?3-methyl-5-phenylpyrazole) have been synthesized and characterized by chemical analysis, FTIR and ³¹P NMR spectroscopy and single-crystal X-ray diffraction. Complex 1 is a doubly bromo-bridged dimer, while complexes 2 and 3 are chloro-bridged dimers. The Cu(II) centers are in a distorted tetrahedral geometry for 1 and 2 and a distorted square pyramidal N₂Cl₃ environment for 3.     

Synthesis and characterization of new LnxSb2−xSe3 (Ln: Yb, Er) nanoflowers and their physical properties

New Ln_xSb_2−xSe₃ (Ln: Yb³⁺, Er³) based nanomaterials were synthesized by a co-reduction method. Powder XRD patterns indicate that the Ln_xSb_2−xSe₃crystals (Ln=Yb³⁺, Er³⁺, x=0.00-0.12) are isostructural with Sb₂Se₃. The cell parameters b and c decrease for Ln=Er³⁺ and Yb³⁺ upon increasing the dopant content (x), while a increases. SEM images show that doping of the lanthanide ions in the lattice of Sb₂Se₃ generally results in nanoflowers. UV-vis absorption and emission spectroscopy reveals mainly electronic transitions of the Ln³⁺ ions in case of Yb³⁺ doped nanomaterials. Emission spectra of doped materials, in addition to the characteristic red emission peaks of Sb₂Se₃, show additional emission bands centered at 955 nm, originating from the ²F_7/2→²F_5/2 transition (f-f transitions) of the Yb³⁺ ions. DSC curves indicate that Sb₂Se₃ has the highest thermal stability. The temperature dependence of the electrical resistivity of doped-Sb₂Se₃ with Yb³⁺ and Er³⁺ was studied.     

Co-reduction synthesis of new LnxSb2−xS3 (Ln: Nd, Lu, Ho) nanomaterials and investigation of their physical properties

New Ln_xSb_2−xS₃ (Ln: Lu³⁺, Ho³⁺, Nd³⁺)-based nanomaterials were synthesized by a co-reduction method. Powder XRD patterns indicate that the Ln_xSb_2−xS₃ crystals (Ln=Lu³⁺, Ho³⁺, x=0.00−0.1 and Ln=Nd³⁺, x=0.00−0.08) are isostructural with Sb₂S₃. SEM images show that doping of Lu³⁺ and Ho³⁺ ions in the lattice of Sb₂S₃ results in nanorods while that in Nd³⁺ leads to nanoflowers. UV-vis absorption and emission spectroscopy reveal mainly electronic transitions of the Ln³⁺ ions in case of Ho³⁺ and Nd³⁺ doped nanomaterials. Emission spectra show intense transitions from excited to ground state of Ln³⁺. Emission spectra of doped materials, in addition to the characteristic red emission peaks of Sb₂S₃, show other emission bands originating from f-f transitions of the Ho³⁺ ions. TGA curves indicated that Sb₂S₃ has the highest thermal stability. The electrical conductance of Ln-doped Sb₂S₃ is higher than undoped Sb₂S₃, and increase with temperature.     

Effects of Halogen Bonding in Chemical Activity of Lead(II) Electron Pair: Sonochemical Synthesis,Structural Studies,and Thermal Analysis of Novel Lead(II) Nano Coordination Polymer

The nanoflower lead(II) coordination compound {[Pb(phen)(μ‐CH₃COO)][PF₆]}_n ( 1 ) (phen = 1,10‐phenanthroline) was synthesized by a sonochemical method. The nanostructure was characterized by using scanning electron microscopy (SEM), X‐ray powder diffraction, elemental analysis, and thermal analysis. The single‐crystal X‐ray structure shows that the overall structure of 1 is a 1D coordination polymer. Complex 1 has a bridging acetate pathway. Three halogen bonds observed in the structure and the strong halogen bonding of F–Pb causes chemical activity of the lead electron pair. This is further extended into a 3D supramolecular structure by weak π–π intermolecular interactions. The coordination number of the lead(II) ions is six, resulting in PbN₂O₄. PbO nanoparticles were obtained by the thermolysis of 1 at 180 °C with oleic acid as a surfactant. The morphology and size of the prepared PbO nanoparticles were further observed using scanning electron (SEM) and transmission electron microscopy (TEM), and were analyzed by X‐ray photoelectron spectroscopy (XPS).     

Synthesis,Crystal Structure and Theoretical Calculations of N-Benzyl-1-(5-(3-chlorophenyl)-1,3,4-oxadiazol-2-yl)cyclopentanamine

N-benzyl-1-(5-(3-chlorophenyl)-1,3,4-oxadiazol-2-yl)cyclopentanamine was synthesized via one-pot reaction of appropriate benzylamine, cyclopentanone,(N-isocyanimino)triphenylphosphorane and m-chlorobenzoic acid. The quantum theoretical calculations for crystal structure were performed by density functional theory(DFT/B3LYP/6-311+G*). From the optimized structure, geometric parameters were obtained and experimental measurements were compared with the calculated data. Frontier molecular orbitals(FMOs), total density of states(DOS), molecular electrostatic potential(MEP), molecular properties, natural charges, NMR parameters and NBO analysis for the product were investigated by theoretical calculations.