In this paper, we will report the preparation of a mixed-valence polyoxometalate compound (Bu4N)(4)[PMo12O40].2DMF.H2O (TBA = tetrabutylammonium; DMF = N,N-dimethyl formamide). The title compound has been photochemically synthesized and characterized by using elemental analysis, IR, solid diffusion reflectance electronic spectra, ESR spectra, XPS, CV and X-ray single-crystal analysis. The crystal lographic data are as follows: monoclinic, P2(1)/c, a = 14.124(3), b = 17.481(4), c = 22.744(5) Angstrom, beta = 101.66(3)degrees, V = 5500(2) Angstrom(3), C70H160Mo12N6O43P, M-r = 2956.29, Z = 2, D-c = 1.785 g/cm(3), F(000) = 2970 and mu(MoKalpha) = 1.412 mm(-1). The structure has been refined to R = 0.0638 and wR = 0.1975 by full-matrix least-squares methods. The title compound is composed of four tetrabutylammonium cations, one [(PMoMo11O40)-Mo-V](4-) heteropoly anion, two N,N-dimethyl formamide and one H2O molecule.

The title complex [(VB(1))(2)DMFHPMo(12)O(40).5DMF, VB(1) = vitamin B(1) (thiamine chloride), DMF = N,N-dimethylformamide] has been synthesized and characterized by elemental analysis, IR, UV-Vis, electron spin resonance, X-ray photoelectron spectroscopy and cyclic voltammetry methods. The X-ray crystal structure revealed that there is one independent molecule in the unit cell of the title complex that contains one mixed-valence heteropolyanion, two VB(1)(+) cations and six DMF molecules. The title complex possesses a centrosymmetrical arrangement in the unit cell, with the P atom at the symmetry center of the heteropolyanion and with eight O atoms surrounding the central P atom, such that two sets of PO(4) tetrahedra are formed. The PO(4) tetrahedra and MoO(6)(6-(7-)) octahedra are disordered in the heteropolyanion. The bond distances of P-O(a) and Mo=O(d) are in the ranges 1.57 (4)-1.70 (4) A and 1.61 (2)-1.67 (2) A, respectively.

The title heteropoly blue, (Bu4N)(6)H-10 [(PMo11MoO40)-Mo-VI-O-V](4) . H2O has been photochemically synthesized and characterized with elemental analysis, solid diffusion reflectance electronic spectra, CV, ESR, XPS, IR spectra, conductivity measurement and X-ray single crystal analysis. The crystallographic data for C96H218Mo48N6O169P4 are as follows: M-r = 8889.76, triclinic, P (1) over bar, a = 1.4142 (3) nm, b = 2.6027 (5) nm, c = 2.6403(5) nm, alpha = 113.96(3)degrees, beta = 90.05(3)degrees, gamma = 105.71(3)degrees, V = 8.481 (3) nm(3), Z = 1, D-c = 1.741 g/cm(3), F (000) = 4264, mu = 1.798 mm(-1). The X-ray crystal structure analysis reveals that there Is one independent molecule in the unit cell of the title heteropoly blue which contains four mixed-valence heteropoly anions, six tetrabutylammonium cations and one water molecule. Its molecular structure possesses a centrosymmetrical arrangement in the unit cell. The phosphorus atom is In the crystallographic inversion center of the heteropoly anion and the eight oxygen atoms surrounding central phosphorus atom comprise of a distorted hexahedron. Heteropolyanion has two equal sets of PO4 tetrahedron. The PO4 tetrahedron and the MoO6 octahedron in the polyanion are greatly distorted.

The title supramolecular compound, [HMDH2][(H2PMoMo11O40)-Mo-V] . 2AA . 3H(2)O . DMF (HMD = hexamethylene diamine; AA=acetaldehyde; DMF=N,N-dimethyl formamide), has been photochemically synthesized by using elemental analysis, IR, solid diffusion reflectance, electronic spectra, ESR spectra and X-ray single-crystal analysis. The crystallographic data: triclinic, P (1) over bar, a=14.092(2), b=14.347(3), c=14.358(3)Angstrom, alpha = 75.10(3), beta = 80.70(3), gamma = 80.73(3)degrees, V = 2746.6(10)Angstrom (3), Z = 2, M-r = 2081.68, D-c=2.517g/cm(3), F(000) =1970, mu (MoK alpha) =2.766mm(-1). The structure has been refined to R =0.0832 and wR=0.2638, by full-matrix least-squares method. The title compound is composed of hexamethylene diamine, two acetaldehyde molecules, three water molecules, one N,N-dimethylformamide and [(H2PMoMo11O40)-Mo-V](2-) heteropoly anion.

The title supramolecular compound, [HMDH2][H2PMoVMo11O40] ·2AA ·3H2O ·DMF(HMD = hexamethylene diamine; AA=acetaldehyde; DMF=N,N-dimethyl formamide), has been photochemically synthesized by using elemental analysis, IR, solid diffusion reflectance electronic spectra, ESR spectra and X-ray single-crystal analysis. The crystallographic data: triclinic, P1 , a=14.092(2), b=14.347(3), c= 14.358(3)Å, α = 75.10(3), β = 80.70(3), γ = 80.73(3)° , V = 2746.6(10)Å3, Z = 2, Mr = 2081.68, Dc=2.517g/cm3, F(000) =1970, μ(MoKα) =2.766mm-1. The structure has been refined to R =0.0832 and wR=0.2638, by full-matrix least-squares method. The title compound is composed of hexamethylene diamine, two acetaldehyde molecules, three water molecules, one N,N-dimethylformamide and [H2PMoVMo11O40]2- heteropoly anion.

The fluorescence enhancement of the Eu-dibenzoylmethane(DBM)-cetylpyridinium-chloride (CPC) system was studied. The fluorescence intensity of the system can be greatly increased by Gd3+ in the presence of triethanolamine(TEA). The optimum conditions for enhanced fluorescence of the Eu-Gd-DBM-CPC system were examined. It was a linear function of the Eu3+ concentration in the range of 1.0x10(-10)similar to 1.0x10(-8) mol dm(-3) under the optimized conditions. The detection limit was 2.6 x 10(-11) mol dm(-3) in an aqueous solution at pH=7.5 similar to 9.5.The Eu-Gd-DBM-CPC system was applied to the determination of europium in rare earth oxides with satisfactory results. The mechanism of enhanced fluorescence was discussed.

The fractal property and low frequency Raman scattering of Eu(DBM)(3) nanosized microcrystals were investigated. The influence of the fractal structure of Eu(DBM)(3) non crystalline solids on low frequency scattering was studied. It was found that vibrational excitations on the fractal are localized and can be described in terms of fractions. It was shown that reduced Raman scattering intensity is of a power law dependence of the vibrational frequencies for all samples. The fractal and spectral dimension were also determined, we found that our experimental value was in fair agreement with the theoretical one.

The colloids or Eu(DBm)(3) and ultrafine particles Eu(DBM)(3) were perpared. The particle sizes determined by X-ray and by TEM measurements were in 7-30nm range. Their UV absorption and fluorescence spectra were compared with each other and with those of the solid sample, it was shown that the D-8(1) -> F-7(1,2) transition was observed in the colloids of Eu(DBM)(3) at room temperature. The increase of the excited-state S-1 and T-1 energy, the peak positions of UV absorption shifted to shorter wavelength, the changes of the absoprtion coefficient with decreasing size were observed,