The assembly of "S3N"-ligands decorated with an azo-dye as potential sensors for heavy metal ions.

An "S3N-ligand azo-dye" conjugate has been synthesised with a view to the development of a sensor for heavy metal ions. Complexation of this system with Ag(i), Hg(ii) and Cu(ii) salts has been investigated and an X-ray structure has been obtained for a Hg(ii) complex. Complexation of the conjugated dye to these metals results in a bathochromic shift in the absorption maximum of the azo dye, an effect which is most pronounced for Cu(ii).

Imaging Water Dissociation on TiO(2)(110).

Scanning tunneling microscopy has been used to identify the adsorption site of H(2)O on TiO(2)(110)-(1 x 1) at 150 K, and to monitor the site of the dissociation products at 290 K. Water adsorbs onto the rows of fivefold coordinated Ti atoms at 150 K, dissociating by 290 K to form bridging but not terminal hydroxyls. This points to the involvement of bridging O vacancies in the dissociation pathway.

Performance of the VUV beamline 4.1 at the SRS, Daresbury Laboratory.

The performance of a recently commissioned beamline, designated BL4.1, at the SRS, Daresbury Laboratory, is described. This beamline covers the energy range 15 >/= hupsilon >/= 200 eV, using a spherical grating monochromator, and is equipped with a UHV surface-science endstation containing a Scienta SES200 and an HA54 angle-resolving electron-energy analyser. Design parameters and optical specifications are tabulated. Monochromator resolution has been determined by measuring the Fermi edge of a Pt foil cooled to 40 K and these values are compared with the calculated resolution. The flux delivered to the endstation has been measured directly using a calibrated photodiode. The performance of the beamline is further illustrated by reference to a study of the angular distribution of photoemitted intensity from a band-gap state on a TiO(2)(110) 1 x 2 surface.