Observation of a chi(c2)' candidate in gamma gamma --> DD production at belle

We report on a search for new resonant states in the process gamma gamma --> DD. A candidate C-even charmonium state is observed in the vicinity of 3.93 GeV/c2. The production rate and the angular distribution in the gamma gamma center-of-mass frame suggest that this state is the previously unobserved chi(c2)', the 2(3)P2 charmonium state.     

On the O2 binding of Fe-porphyrin, Fe-porphycene, and Fe-corrphycene complexes

Based on our previous study for the O2 binding of the Fe-Por complex, this study investigates the O2 binding mechanism in the Fe-porphyrin isomers, Fe-porphycene (FePc), and Fe-corrphycene (FeCor) complexes. By calculating the potential energy surface of the O2 binding, the present study explains the reason for the dramatic increase of O2 affinities observed in the FePc complex. In the case of FeCor-O2, the O2 binding process includes the intersystem crossing from a triplet to singlet state, as in the FePor-O2 complex. However, FePc-O2 uses only a singlet surface. This is because the ground state of the FePc complex in the deoxy state is a triplet state, while those of FePor and FeCor are a quintet state. Such difference originates from character of the SOMO. We estimated an equilibrium constant for the O2 binding that reasonably reproduced the trend observed in the experiments.     

Electrochemical studies of (−)-epigallocatechin gallate and its interaction with DNA

In this paper, an electrochemical investigation of (−)-epigallocatechin gallate (EGCG) and its interaction with DNA is presented. Via an electrochemical approach assisted by ultraviolet–visible (UV–Vis) spectroscopy, we propose that EGCG can intercalate into DNA strands forming a nonelectroactive complex, which results in the decrease of the anodic peak current of EGCG. Meanwhile, an electrochemical study with the DNA–Cu(II)–EGCG system shows that damage to DNA can be recognized electrochemically via the increase in the anodic peak current resulting from the oxidation of guanine and adenine bases. The damage can also be recognized spectrophotometrically via an increase in the 260 nm absorption band. In addition, it was found that EGCG is able to discriminate dsDNA from ssDNA, making a potential electrochemical indicator for the detection of DNA hybridization events. A rapid and convenient method of detecting EGCG was also developed in this work. Figure Interaction of EGCG with DNA and damage to DNA in the presence of Cu(II) Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.     

Interfacial structure of Co porphyrins on Au(111) electrode: Interaction of porphyrin molecules with substrate

Interfacial structures of cobalt(II) porphine (CoP) and [2,3,7,8,12,13,17,18‐octaethyl‐21H,23-H-porphine]cobalt(II) (CoOEP) have been studied on Au(111) electrode using electrochemical scanning tunneling microscopy (EC-STM), in-situ X-ray diffraction, and density functional theory (DFT) calculations. The adsorption of porphyrins affects the reconstruction of Au(111) surface. The adsorption of CoP causes a lifting of the reconstruction to a complete 1 × 1 structure of Au(111). On CoOEP modified Au(111), the unit cell periodicity of the reconstructed substrate structure expands compared with the √3 × 23 structure of bare Au(111). The same expanded substrate structure was observed on Au(111) modified with OEP without the coordinated Co ion; the coordinated metal ion of the adsorbed porphyrin molecule does not affect the substrate structure. This result indicates that the interaction of conjugated π electrons of porphyrin with the substrate is stronger than that of the coordinated Co ion. In-situ X-ray diffraction and DFT calculation support non-covalent interaction of porphyrins with the Au(111) surface.