Koichi Nozaki

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Photochemical properties of 4-coumarinylmethyl derivatives (CM-X, X = Br, Cl, OH, OPh, SH, and SPh) in solution were studied by laser flash photolysis and DFT calculations. It was found that CM-Br and CM-SPh undergo photoinduced bond dissociation in the lowest excited singlet state, yielding the 4-coumarinylmethyl radical (CMR) and the corresponding radical(More)
An NAD/NADH-functionalized ligand, benzo[b]pyrido[3,2-f][1,7]-phenanthroline (bpp), was newly synthesized. A Ru compound containing the bpp ligand, [Ru(bpp)(bpy)2](2+), underwent 2e(-) and 2H(+) reduction, generating the NADH form of the compound, [Ru(bppHH)(bpy)2](2+), in response to visible light irradiation in CH3CN/TEA/H2O (8/1/1). The UV-vis and(More)
This paper describes an audio steganography using low bits coding. This approach is to replace the data of lower bit in a cover audio data by a secret data. We used wave file as an audio data. The wave file format is a subset of Microsoft’s RIFF specification for the storage of multimedia files. We used 8 bits mono audio data. The secret data is a(More)
Temperature and substituent effects on the stereo- and regioselectivity have been investigated in the photochemical [2 + 2] cycloaddition reaction, the so-called Paternò-Büchi (PB) reaction, of unsymmetrically substituted furans 2a,b (2-methyl- and 3-methylfuran) with aromatic carbonyl compounds 1a,b (benzaldehyde and benzophenone). The regio-random but(More)
The photophysical properties of singlet and triplet metal-to-ligand charge transfer (MLCT) states of [Cu(I)(diimine)(2)](+), where diimine is 2,9-dimethyl-1,10-phenanthroline (dmphen), 2,9-dibutyl-1,10-phenanthroline (dbphen), or 6,6'-dimethyl-2,2'-bipyridine (dmbpy), were studied. On 400 nm laser excitation of [Cu(dmphen)(2)](+) in CH(2)Cl(2) solution,(More)
Steganography is one of the best data hiding technique in the world which can be used to hide data without its presence felt. In today's digital world most of us communicate via use of electronic media or internet. Most people among us remain unaware about the data loss or data theft which can happen on online transmission of data or message. Valuable(More)
Now a day's use of an internet in public masses is growing. So large amount of data is stored in computers and transmitted over networks. Data security is main issue now days. Steganography is one of data hiding technique. In this paper we use a multilevel technique in audio steganography. By using multilevel technique we use three methods instead of(More)
Phosphorescence spectra of tris(2,2'-bipyridine) metal compounds, [M(bpy)3]n+, where M = Zn(II), Ru(II), Os(II), Rh(III), and Ir(III), were calculated using a harmonic oscillator approximation of adiabatic potential surfaces obtained by density functional theory (DFT). Using the Huang-Rhys (S) factors calculated by theoretical Franck-Condon analysis of T1(More)
The reaction of the digold(I) complex [Au2(dppm)(D-pen)2](2-) ([1](2-); dppm = bis(diphenylphosphino)methane and D-pen = D-penicillaminate) with Zn(2+) in a 1:1 ratio gave the heterometallic Au(I)2Zn(II) trinuclear complex [Au2Zn(dppm)(D-pen)2] ([3]), in which the Zn(2+) ion is coordinated by [1](2-) in an N2O2S2 octahedral geometry with the trans(O)(More)