(Z)-4-[(2-Amino­anilino)(phen­yl)methyl­idene]-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one

The mol­ecule of the title compound, C23H20N4O, assumes a non-planar conformation in which the pyrazolone ring forms dihedral angles of 10.33 (11), 65.34 (11) and 63.52 (10)° with the three benzene rings. In the crystal, the mol­ecules are linked by inter­molecular N—H⋯N hydrogen bonds, generating chains parallel to the b axis. The secondary amino group is involved in an intra­molecular N—H⋯O hydrogen bond

Near-Infrared (NIR) Luminescent Homoleptic Lanthanide Salen Complexes Ln(4)(Salen)(4) (Ln = Nd, Yb Or Er)

The series of homoleptic tetranuclear [Ln(4)(L)(2)(HL)(2)(NO3)(2)(OH)(2)]center dot 2(NO3) (Ln = Nd, 1; Ln = Yb, 2; Ln = Er, 3; Ln = Gd, 4) have been self-assembled from the reaction of the Salen-type Schiff-base ligand H2L with Ln(NO3)(3)center dot 6H(2)O (Ln = Nd, Yb, Er or Gd), respectively (H2L: N, N'-bis(salicylidene) cyclohexane-1,2-diamine). The result of their photophysical properties shows that the strong and characteristic NIR luminescence for complexes 1 and 2 with emissive lifetimes in microsecond ranges are observed and the sensitization arises from the excited state (both (LC)-L-1 and (LC)-L-3) of the Salen-type Schiff-base ligand with the flexible linker.National Natural Science Foundation 21173165, 20871098Ministry of Education of China NCET-10-0936Higher Education of China 20116101110003State Key Laboratory of Structure Chemistry 20100014Education Committee Foundation of Shaanxi Province 11JK0588Hong Kong Research Grants Council, P. R. of China HKBU 202407, FRG/06-07/II-16)Hong Kong Research Grants Council, Robert A. Welch Foundation F-816Texas Higher Education Coordinating Board ARP 003658-0010-2006Petroleum Research Fund 47014-AC5Chemistr

The First Example of Tb-3-Containing Metallopolymer-Type Hybrid Materials with Efficient and High Color-Purity Green Luminescence

In the series of homo-leptic trinuclear complexes {[Ln(3)(L)(4)Cl-4(MeOH)(H2O)]center dot Cl} (Ln = La, 1; Ln = Eu, 2; Ln = Tb, 3 or Ln = Gd, 4) self-assembled from the allyl-modified benzimidazole-type ligand HL (4-allyl-2-(1H-benzo[d]imidazol-2-yl)-6-methoxyphenol) and LnCl(3)center dot 6H(2)O, a suitable energy level match endows efficient green luminescence (Phi(overall) = 72%) of Tb-3-arrayed complex 3. The copolymerization between each of these complex monomers 1-4 and C=C-containing MMA (methyl methacrylate) or NBE (norbornene) shows that degradative chain transfer of the terminal four flexible allyl groups within restrains their radical polymerization with MMA while it does not hinder their effective ring-opening metathesis polymerization (ROMP) with NBE. Thus, two kinds of PMMA-supported doping hybrid materials 1@PMMA, 2@PMMA, 3@PMMA and 4@PMMA and PNBE-supported metallopolymer-type hybrid materials Poly( NBE-1), Poly(NBE-2), Poly(NBE-3) and Poly(NBE-4) are obtained, respectively. Especially for both 3@PMMA and Poly(NBE-3) with high color-purity characteristic green emission of Tb3+ ions, improved physical properties including significantly enhanced luminescence (Phi(overall) = 76% or 83%) are observed, and covalent-bonding endows a higher-concentration self-quenching as compared to physical doping.National Natural Science Foundation 21373160, 91222201, 21173165Program for New Century Excellent Talents in University from the Ministry of Education of China NCET-10-0936Doctoral Program of Higher Education 20116101110003Science and Technology and Innovation Project of Shaanxi Province 2012KTCQ01-37Graduate Innovation and Creativity Fund (Visiting Learner) of Northwest University in P. R. ChinaChemistr

2-{[2-(2-Hy­droxy-3-meth­oxy­benzyl­idene)hydrazin-1-yl­idene]meth­yl}-6-meth­oxy­phenol

The title compound, C16H16N2O4, was obtained from the reaction of hydrazine hydrate and o-vanilin in absolute ethanol. The mol­ecule is almost planar (except for the methyl H atoms), with a mean deviation from the plane of 0.0259 Å. The mol­ecular structure also exhibits an approximate non-crystallographic twofold axis. Intra­molecular O—H⋯N hydrogen bonds occur. In the crystal, inter­molecular C—H⋯O hydrogen bonds generate mol­ecular zigzag sheets. The sheets stack through C—H⋯π inter­actions, leading to a three-dimensional-network

Behavior of fast earthward flow near the braking region: Hall MHD simulation

Behavior of the fast earthward flow near the braking region in the magnetotail during a substorm is investigated using the Hall MHD simulation. The results indicate that the high-speed earthward plasma flow is associated with fast reconnection in the middle tail. The fast flow is mainly confined in the range $-1.5R_{E} < z < 1.5R_{E}$ . In the region of $-15R_{E} < x < -9R_{E}$ , due to intermittent magnetic reconnection, the earthward flow exhibits a fluctuating property, i.e., the flow is localized in space and is bursty in time. The pile-up of the magnetic flux and plasma in the near-Earth region leads to formation of the fast-flow braking region or dipolarization front. After colliding into the fast-flow braking region, a part of the Earth flow bounces back, and leads to an intermittent tailward flow in the near-Earth magnetotail

Effect of laser pulse width on wave packet motion in femotosecond pump-probe pulses

The dependence of the wave packet process of three-level ladder K-2 molecules on pulse width was investigated via time-dependent wave packet method, and was firstly quantified. There is no Autler-Townes splitting in the photoelectron spectrum with weaker pump intensity or shorter pulse width. The oscillation period of wave packet increases and the oscillation amplitude decreases with increasing pulse width. The pulse width affects Rabi oscillation, which results in the periodical change of the populations of the electronic state. Quantifying its effect on the population of the excited state shows that the change frequency varies with increasing pump intensity. The results illustrates that the needed population in electronic state of interested can be obtained by controlling pulse width, which provide some important basis for light manipulation of molecular processes experimentally. (C) 2016 Elsevier GmbH. All rights reserved

Kinetics Study on the Modification Process of Al2O3 Inclusions in High-Carbon Hard Wire Steel by Magnesium Treatment

The aim of the experiment in this work is to modify the Al2O3 inclusions in high-carbon hard wire steel by magnesium treatment. The general evolution process of inclusions in steel is: Al2O3 → MgO·Al2O3(MA) → MgO. The unreacted core model was used to study the modification process of inclusions. The results show that the complete modification time (tf) of inclusions is significantly shortened by the increase of magnesium content in molten steel. For Al2O3 inclusions with radius of 1 μm and Mg content in the range of 0.0005–0.0055%, the modification time of Al2O3 inclusions to MA decreased from 755 s to 25 s, which was reduced by 730 s. For Al2O3 inclusions with a radius of 1.5 μm and Mg content in the range of 0.001–0.0035%, the Al2O3 inclusions were completely modified to MgO inclusions from 592 s to 55 s. The Mg content in the molten steel increased 3.4-fold, and the time for complete modification of inclusions was shortened by about 10-fold. With the increase of Al and O content in molten steel, the complete modification time increased slightly, but the change was small. At the same time, the larger the radius of the unmodified inclusion is, the longer the complete modification time is. The tf of Al2O3 inclusions with a radius of 1 μm when modified to MA is 191 s, and the tf of Al2O3 inclusions with a radius of 2 μm when modified to MA is 765 s. According to the boundary conditions and the parameters of the unreacted core model, the MgO content in inclusions with different radius is calculated. The experimental results are essentially consistent with the kinetic calculation results

Wavelength dependence of Autler-Townes splitting in a four-level ladder molecular system

We theoretically investigated the Autler-Townes (AT) splitting in the photoelectron spectra of four-level ladder K-2 molecules in the presence of two control pump fields and one probe field by employing the time-dependent wave packet approach. The wavelength dependence of AT splitting on three laser pulses was studied in detail. The photoelectron spectra show triple splitting with symmetric profiles, but with asymmetric profiles when the wavelength is changed. The shifts of the absorption peaks are predicted by using an analytical fitting function when the wavelength of one of the three fields is changed, and the functional dependence appears to be linear. These novel results are of importance for the molecular spectroscopy, and may stimulate further theoretical studies analytically from the first principles. Copyright (C) EPLA, 201

influenceoffemtosecondlaserparametersonautlertownessplittingofthreelevelladdermolecules

利用三态模型和含时波包法，研究了K2分子在强飞秒泵浦一探测激光场中泵浦／探测场强、波长对光电子能谱Autler—Townes（AT）分裂的影响．通过分别改变两激光场的场强或者波长预测AT峰移和间距，并且首次量化了AT分裂的峰移和间距．光电子能谱在共振时显示为对称双峰，失谐时为非对称双峰。AT分裂间距随泵浦场强增大而增大，但不因探测场强改变而改变