Articles you may be interested inSynchronized time-and high-field-resolved all-optical pump-probe magneto-optical setup based on a strong alternating magnetic field and its application in magnetization dynamics of high coercivity magnetic medium Rev. Sci. Instrum. 82, 034703 (2011); 10.1063/1.3565156Field-dependent ultrafast dynamics and mechanism of magnetization reversal across ferrimagnetic compensation points in GdFeCo amorphous alloy films Submicron-scale spatial feature of magnetization reversal dynamics induced by femtosecond optical pulse irradiation in a small external magnetic field was investigated by time-resolved magneto-optical Kerr microscopy on TbFeCo thin film. The magnetization reversal time near the magnetic domain boundary is dominated by an effective magnetic field generated from the peripheral domain by dipole-dipole interaction. The magnetization reversal is accelerated as high as 4.5 times ͑from 3.4 ns to 750 ps͒ when reducing the reversed domain size from 1.5 to 0.4 m due to concentration of dipole-dipole interaction.

Reductive elimination of R-R from dialkyl(2,2 -bipyridyl)nickel( ), [NiR 2 (bpy)] 1 (R = CH 3 ( 1a ), C 2 H 5 ( 1b ), n -C 3 H 7 ( 1c )), caused by π -coordination of electron-accepting aromatic compounds and reductive elimination of Ar-Ar from [NiAr 2 (bpy)] 2 (Ar = C 6 F 5 ( 2a ) and pyrazolyls ( 2b and 2c )) promoted by electron-accepting aromatic compounds, Lewis acids, and Brønsted acids have been investigated. 1 H-NMR and kinetic data indicate that π -coordination of the electron-accepting aromatic compound to [NiR 2 (bpy)] leads to the reductive elimination of R-R. The rate of the reductive elimination obeys the second-order rate law,Plots of log k vs Σ σ p of the electron-accepting aromatic compound give a line with a slope of 1.8. Brønsted acids cause reductive elimination of Ar-Ar from 2 selectively under several reaction conditions (e.g., 2a with CF 3 COOH in air and 2b with HBr). The reductive elimination reaction of 2a caused by CF 3 COOH obeys the second-order rate law, − 1 at 300.5 K. UV-vis data give information about the electronic states of 2 and the 2b -Brønsted acid adduct. Poly(6-hexylpyridine-2,5-diyl) with a higher molecular weight has been prepared according to the basic information.Reductive elimination is one of the most fundamental reactions in organometallic chemistry.1-4 The reductive elimina-is considered to be a key step in Ni-and Pdcomplex promoted organic synthesis 1,5,6 and polymer synthesis. 7,8 Factors that control the reductive elimination from diorganometallic complexes, [M(Y)(Y )L n ] (M = Ni, Pd; L = neutral ligand such as 2,2 -bipyridyl and tertiary phosphines) have long been investigated. The diaryl nickel complex has been isolated mainly with electron-withdrawing aryl groups that stabilize the Ni-aryl bond.In this paper, we report details of (i) the reductive elimination reaction of [Ni(alkyl) 2 (bpy)] (bpy = 2,2 -bipyridyl) accelerated by the coordination of electron-accepting aromatic compounds such as m-and p-C 6 H 4 (CN) 2 and (ii) the reductive elimination reaction of [Ni(aryl) 2 (bpy)] induced by Lewis acid and protic acids. The Brønsted acids usually induce the cleavage of metal-organic (M-Y) bonds to liberate Y-H compounds; 1,3c,9f,10 however, the present investigation reveals that it can cause selective reductive elimination when the organic group is the electron-accepting aryl group.(2) Analysis of these reductive elimination reactions is expected to improve our understanding of the nickel-complex-promoted synthetic reactions. A part of these results have been published in a communication form. 9c have been determined by X-ray crystallography; they take a square planar structure around Ni, as previously reported for 2c. The molecular structure of 2a is shown in Figure 1 and that of 2b is given in the supporting data.Reductive

The four component system consisting of bis[2-(o-chlorophenyl)-4,5-diphenylimidazole] (Cl-HABI), N,N'-bis(diethylamino)benzophenone (EAB), N-phenylglycine (NPG) and an iodonium salt (BIP-T) can be used for the photoinitiation of radical polymerization reactions. The excited state processes involved are reported and all the transient species, including the triplet state and ketyl radical of EAB as well as the lophyl radical, are characterized. Rate constants of interaction between the different partners in the four component system are determined. Redox potentials of the different compounds are evaluated enabling the free energies for electron transfer reactions to be calculated. An overall scheme for the evolution of the excited states and a general discussion on the role played by the different components in photoinitiating polymerization are then provided.

The areal density of holographic memory can be increased by decreasing the aperture size of the optical system; however, this causes the deterioration of a reproduced image due to the elimination of the high-frequency components of the image. We have developed two-dimensional partial response maximum likelihood (2D PRML), which is based on the previously proposed ''decision feedback Viterbi algorithm'' and added the new idea of the ''constant-weight constraint (CW constraint)'' and the ''amplitude PR method''. We have confirmed the improvement in error rate using 2D PRML compared with the conventional differential detection method in a high-density holographic memory system by simulation.

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