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81.
82.
Elham Noori Noushin Mir Masoud Salavati-Niasari Tahere Gholami Maryam Masjedi-Arani 《Journal of Sol-Gel Science and Technology》2014,69(3):544-552
Employing a Schiff base ligand in a hydrothermal sol–gel method for preparation of TiO2 nanostructures was studied. The as-prepared products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectrum, electron dispersive X-ray spectroscopy and ultraviolet–visible spectroscopy. It is shown that in the controlled reaction conditions, a Schiff base ligand containing hard atoms is capable of driving the growth mechanism in a way that anisotropic shapes of TiO2 nanostructures are formed. Considering the structure of the Schiff base ligand, the possible growth mechanism of TiO2 nanostructures is proposed. The optical studied as well as calculated molecular orbital structure of ligand by density functional theory is done. 相似文献
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86.
Ilaria D'Auria Marina Lamberti Mina Mazzeo Stefano Milione Claudio Pellecchia 《Journal of polymer science. Part A, Polymer chemistry》2014,52(1):49-60
New aluminum alkyl complexes, supported by o‐phenylene‐derived phosphido diphosphine pro‐ligands [Ph‐PPP]‐H and [iPr‐PPP]‐H ([Ph‐PPP]‐H = bis(2‐diphenylphosphinophenyl)phosphine; [iPr‐PPP]‐H = bis(2‐diisopropylphosphinophenyl)phosphine) are reported. Compounds [Ph‐PPP]AlMe2 ( 1 ), [iPr‐PPP]AlMe2 ( 2 ), and [Ph‐PPP]AliBu2 ( 3 ) have been synthesized by reaction of the pro‐ligand with the appropriate trialkyl aluminum precursor and have been characterized by 1H, 13C and 31P NMR spectroscopy. The solution NMR data and theoretical calculations suggest for all complexes trigonal bipyramidal structures with C2v symmetry in which the phosphido diphosphine ligand acts as a κ3 coordinated ligand. All complexes promote the ring‐opening polymerization of ε‐caprolactone, L‐ and rac‐lactide. Polyesters with controlled molecular parameters (Mn, end groups) and low polydispersities are obtained. Upon addition of isopropanol, efficient binary catalytic systems for the immortal ring‐opening polymerization of the cyclic esters are produced. Preliminary investigations show the ability of these complexes to promote copolymerization of l ‐lactide and ?‐caprolactone to achieve copolymers whose microstructures are depending on the structure of the catalyst. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 49–60 相似文献
87.
Amirhassan?AmiriEmail authorView authors OrcID profile Mehdi?Baghayeri Mina?Sedighi 《Mikrochimica acta》2018,185(8):393
A magnetic sorbent was fabricated by coating the magnetized graphene oxide with polystyrene (PS) to obtain a sorbent of the type GO-Fe3O4@PS. The chemical composition and morphology of the sorbent were characterized. The sorbent was employed for the enrichment of polycyclic aromatic hydrocarbons (PAHs) from water samples. Various parameters affecting the enrichment were investigated. The PAHs were then quantified by gas chromatography with flame ionization detection. Linear responses were found in the range of 0.03–100 ng mL?1 for naphthalene and 2-methylnaphthalene, and of 0.01–100 ng mL?1 for fluorene and anthracene. The detection limits (at an S/N ratio of 3) range between 3 and 10 pg mL?1. The relative standard deviations (RSDs) for five replicates at three concentration levels (0.05, 5 and 50 ng mL?1) of analytes ranged from 4.9 to 7.4%. The method was applied to the analysis of spiked real water samples. Relative recoveries are between 95.8 and 99.5%, and RSD% are <8.4%. 相似文献
88.
A new method for multi-component synthesis of 1,4-dihydropyridine derivatives (1,4-DHPs) in the presence of meglumine supported on multiwalled carbon nanotubes (MWCNTs@meglumine) as a new heterogeneous, highly efficient and reusable catalyst was investigated. The reaction was performed under ultrasonic irradiation in EtOH at room temperature. A new, highly efficient heterogeneous catalyst, short reaction times, high to excellent yield of products, and safe and clean conditions are the advantages of the presented method. 相似文献
89.
H. K. Barrenscheen Margarete Frey F. Feigl L. T. Fairhall M. Settimj D. Ganassini A. Necke H. Müller Ch. Badham H. B. Taylor G. Moillère F. Weyrauch St. Litzner F. Grendel N. Schoorl H. Begemann A. Berat G. Widmark B. Vahlquist E. M. P. Widmar S. L. Oerskov J. P. Gregersen P. Iversen H. W. Mook D. D. van Sluke W. M. Kirjan W. C. Stadie E. C. Ross K. Lang H. Waelsch Gertrud Klepetar I. St. Lorant L. Kopetz J. W. Heim W. W. Práwdicz-Neminski Z. Babitsch J. F. Reith Th. von Fellenberg R. G. Turner Mina Z. Weeks A. Castille V. Henri 《Analytical and bioanalytical chemistry》1934,98(3-4):147-160
90.
Tafazzoli M Ghiasi M Moridi M 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,70(2):350-357
Erigeroside was extracted from Satureja khuzistanica Jamzad (Marzeh Khuzistani in Persian, family of lamiaceae), and (1)H, (13)C, (13)C{(1)H}, (1)H-(1)H COSY, HMQC and J-HMBC were obtained to identify this compound and determine a complete set of J-coupling constants ((1)J(C-H), (2)J(C-H), (3)J(C-H) and (3)J(H-H)) values within the exocyclic hydroxymethyl group (CH(2)OH) and anomeric center. In parallel, density functional theory (DFT) using B3LYP functional and split-valance 6-311++G** basis set has been used to optimized the structures and conformers of erigeroside. In all calculations solvent effects were considered using a polarized continuum (overlapping spheres) model (PCM). The dependencies of (1)J, (2)J and (3)J involving (1)H and (13)C on the C(5')-C(6') (omega), C(6')-O(6') (theta) and C(1')-O(1') (phi) torsion angles in erigeroside were computed using DFT method. Complete hyper surfaces for (1)J(C1',H1'), (2)J(C5',H6'R), (2)J(C5',H6'S), (2)J(C6',H5'), (3)J(C4',H6'R), (3)J(C4',H6'S) and (2)J(H6'R-H5'S) as well as (3)J(H5',H6'R) were obtained and used to derive Karplus equations to correlate these couplings to omega, theta and phi. These calculated J-couplings are in agreement with experimental values. These results confirm the reliability of DFT calculated coupling constants in aqueous solution. 相似文献