Current interests in the chemistry of high-nuclearity transition-metal complexes draw from their utility in the emerging science of nanomaterials, as models for the multimetal active sites of metal-storage proteins, and as single molecule magnets (SMMs). In addition, such super-sized molecules often show a variety of supramolecular interactions. The “self-assembly” process of generating a high-...

A large-scale gradient in the metal abundance has been detected with ASCA from an X-ray bright cluster of galaxies AWM7. The metal abundance shows a peak of 0.5 solar at the center and smoothly declines to < ∼ 0.2 solar at a radius of 500 kpc. The gas temperature is found to be constant at 3.8 keV. The radial distribution of iron can be fit with a β-model with β ∼ 0.8 assuming the same core rad...

In plants, algae and cyanobacteria, Photosystem II (PSII) catalyzes the light-driven splitting of water at a protein-bound Mn4CaO5-cluster, the water-oxidizing complex (WOC). In the photosynthetic organisms, the light-driven formation of the WOC from dissolved metal ions is a key process because it is essential in both initial activation and continuous repair of PSII. Structural information is ...

Alkyl chain dynamics in monolayer protected metal cluster systems has been studied by the quasielastic neutron scattering technique, using two different instruments having very different energy windows. Long chain thiolate protected clusters such as Au–ODT (Au–SC18H37) are rotationally frozen at room temperature ~RT! in a wide time scale of 10 to 10 s. The rotator phase is absent at RT even in ...

A detailed abundance analysis of 2 giants of the metal-rich bulge globular cluster NGC 6553 was carried out using high resolutionéchelle spectra obtained at the ESO 3.6m telescope. The temperature calibration of metal-rich cool giants needs high quality photometric data. We have obtained JK photometry at ESO and VI photometry with the Hubble Space Telescope for NGC 6553. The main purpose of thi...

All mammalian metallothioneins characterized contain a single polypeptide chain of 61 amino acid residues, among them 20 cysteines providing the ligands for seven metal-binding sites. Native metallothioneins are usually heterogeneous in metal composition, with Zn, Cd, and Cu occurring in varying proportions. However, forms containing only a single metal species, i.e., Zn, Cd, Ni, Co, Hg, Pb, Bi...

Analysis of spatially resolved ASCA spectra of the intracluster gas in Abell 496 confirms that metal abundances increase toward the center. We also find spatial gradients in several abundance ratios, indicating that the fraction of iron from SN Ia increases toward the cluster center and that the dominant metal enrichment mechanism near the center must be different than in the outer parts.

A highly luminescent freestanding film composed of the quantum cluster, Au(15), was prepared. We studied the utility of the material for specific metal ion detection. The sensitivity of the red emission of the cluster in the composite to Cu(2+) has been used to make a freestanding metal ion sensor, similar to pH paper. The luminescence of the film was stable when exposed to several other metal ...

We report on the metal distribution in the intracluster medium around the radio galaxy 4C+55.16 (z = 0.24) observed with the Chandra X-ray Observatory. The radial metallicity profile shows a dramatic change at 10 arcsec (∼ 50 kpc) in radius from half solar to twice solar at inner radii. Also found was a plume-like feature located at∼ 3 arcsec to the south-west of the centre of the galaxy, which...

Single-walled carbon nanotubes (SWNTs) [1] is now recognized as the most fascinating material of so-called nano-technology in this century. Despite the expectation of future applications, it is still difficult to obtain large amount of pure SWNTs, because the generation process is still not clear. It is well known that transition metals such as La, Y and Sc can be encapsulated inside the fuller...