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The anion of the amino-alcohol 3-dimethylamino-2-propanol has been used to prepare a family of hexanuclear Fe(iii) complexes of general formula [Fe6O2(OH)2(RCO2)10(C5H12NO)2] (R = Me: 1, R = Ph: 2, R = m-MeC6H4: 3, R = o-MeC6H4: 4). The complexes have been characterized by single-crystal X-ray diffraction, IR and elemental analyses. The study of their magnetic properties reveals spin-ground states from S= 2 to S= 5. The thermal decomposition of the [Fe6] complexes results in the loss of the aminoalcohol ligands and the solid state formation of undecanuclear complexes. [ABSTRACT FROM AUTHOR]

Four new metal complexes {M = Pd(II) or Pt(II)} containing the ligand 9-aminoacridine (9AA) were prepared. The compounds were characterized by FT-IR and 1H, 13C, and 195Pt NMR spectroscopies. Crystal structure of the palladium complex of formulae [Pd(9AA)(μ-Cl)]2 · 2DMF was determined by X-ray diffraction. Two 9-acridine molecules in the imine form bind symmetrically to the metal ions in a bidentate fashion through the imine nitrogen atom and the C(1) atom of the aminoacridine closing a new five-membered ring. By reaction with phosphine or pyridine, the Cl bridges broke and compounds with general formulae [Pd(9AA)Cl(L)] (where L = PPh3 or py) were formed. A mononuclear complex of platinum of formulae [Pt(9AA)Cl(DMSO)] was also obtained by direct reaction of 9-aminoacridine and the complex [PtCl2(DMSO)2]. The capacity of the compounds to modify the secondary and tertiary structures of DNA was evaluated by means of circul r dichroism and electrophoretic mobility. Both palladium and platinum compounds proved active in the modification of both the secondary and tertiary DNA structures. AFM images showed noticeable modifications of the morphology of the plasmid pBR322 DNA by the compounds probably due to the intercalation of the complexes between base pairs of the DNA molecule. Finally, the palladium complex was tested for antiproliferative activity against three different human tumor cell lines. The results suggest that the palladium complex of formula [Pd(9AA)(μ-Cl)]2 has significant antiproliferative activity, although it is less active than cisplatin. [ABSTRACT FROM AUTHOR]

Examines the structure, crystal growth and physical anisotropy of KYb(WO[sub 4])[sub 2], a laser matrix.

Examines the crystal structure of monoclinic KGW using single crystal X-ray diffraction data. Location of the principal axis with thermal expansion; Effect of doping on the KGW structure; Changes in lanthanide ionic radii.

Abstract. KGd(WO[sub 4])[sub 2] single crystals doped with Er[sup 3+] have been grown by the flux top-seeded-solution growth method. The crystallographic structure of the lattice has been refined, being the lattice constants a = 10.652(4), b = 10.374(6), c = 7.582(2) Angstrom, beta = 130.80(2) degrees. The refractive index dispersion of the host has been measured in the 350-1500 nm range. The optical absorption and photoluminescence properties of Er[sup 3+] have been characterised in the 5-300 K temperature range. At 5 K, the absorption and emission bands show the (2J + 1)/2 multiplet splittings expected for the C[sub 2] symmetry site of Er in the Gd site. The energy positions and halfwidths of the 72 sublevels observed have been tabulated as well as the cross sections of the different multiplets. Six emission band sets have been observed under excitation of the [sup 4]F[sub 7/2] multiplet. The Judd-Ofelt (JO) parameters of Er[sup 3+] in KGW have been calculated: OMEGA 2 = 8.90 x 10[sup -20] cm[sup 2], OMEGA[sub 4] = 0.96 x 10[sup -20] cm[sup 2], OMEGA[sub 6] = 0.82 x 10[sup -20]cm[sup 2]. Lifetimes of the [sup 4]S[sub 3/2], [sup 4]F[sub 9/2], and [sup 4]I[sub 11/2] multiplets have been measured in the 5-300 K range of temperature and compared with those calculated from the JO theory. A reduction of the [sup 4]S[sub 3/2] and [sp 4]I[sub 11/2] measured lifetimes with increasing erbium concentration has been observed, moreover the presence of multiphonon non-radiative processes is... [ABSTRACT FROM AUTHOR]