We report the results of an investigation on the preparation, spectral, and photoelectrochemical properties of Ru(II)-polypyridyl complexes containing a new phosphonated terpyridine (P-terpy) ligand: [Ru(H(2)P-terpy)(2)] and [Ru(HP-terpy)(Me(2)bpy)(NCS)]. Resonance Raman spectral and luminescence studies allow probing into the nature of the low-energy MLCT transitions observed in these complexes. The crystal and molecular structure of the mixed-ligand complex [Ru(HP-terpy)(Me(2)bpy)(NCS)] based on X-ray diffraction study is reported. This complex appears to be a promising candidate as a photosensitizer in dye-sensitized photoelectrochemical cells based on nanocrystalline films of TiO(2).

Scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and X-ray powder diffraction (XRD) studies on nanocrystalline TiO2 powders and thin films are presented. The size, shape (mostly exposed faces), and ordering of the TiO2 anatase particles in the nanocrystalline films are discussed. The use of the topochemical approach, which considers the properties of (nanocrystalline) solids in terms of crystallographic features of (nano)crystals is suggested. The surface area of sensitizer [bis(4,4‘-dicarboxy-2,2‘-bipyridine)bis(thiocyanato)]ruthenium(II) [abbreviated as (cis-Ru(dcbpy)2(NCS)2] on the semiconductor surface for the different types of anchoring is estimated on the basis of single-crystal X-ray diffraction studies of the esterified form of the complex.

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The atomic surfaces modelling technique has been used to solve the structure of the basic Ni-rich Al±Co±Ni decagonal phase. Formula Al 70.6 Co 6.7 Ni 22.7 , space group P10, ®vedimensional unit-cell parameters: d 1 = d 4 = 4.752 (3) A Ê , d 2 = d 3 = 3.360 (2) A Ê , d 5 = 8.1710 (2) A Ê ; 12 = 34 = 69.295 , 13 = 24 = 45 , 14 = 41.410 , 23 = i5 = 90 (i = 1±4), V = 291.2 (7) A Ê 5 ; D x = 3.887 Mg m À3 . Re®nement based on |F|; 2767 unique re¯ections (|F| > 0), 749 parameters, R = 0.17, wR = 0.06. Describing the structure of quasicrystals embedded in n-dimensional superspace in principle takes advantage of ndimensional periodicity to select the minimal set of degrees of freedom for the structure. The method of modelling of the atomic surfaces yielded the ®rst fully detailed structure solution of this phase. Comparison with numerous former, less accurate models con®rms several features already derived, but adds a new essential insight of the structure and its complexity. The atoms ®ll the space forming recurrent structure motifs, which we will (generically) refer to as clusters. However, no unique cluster exists, although differences are small. Each cluster shows a high degree of structural disorder. This gives rise to a large con®gurational entropy, as much as expected in a phase which is stable at high temperature. On the other side, the cluster spatial arrangement is perfectly quasiperiodic. These considerations, corroborated by analysis of the structural relationship with neighbouring periodic phases, strongly suggest the existence of a non-local, long-range interaction term in the total energy which may be essential to the stability.