Rare earth complexes containing

Huang reported the unique rare earth complex containing two types of ionized ligands (Hsalen and salen) in 1990 [78]. Eu(Hsalen)(salen) H20 crystallizes in the monoclinic system with a space group P2 a with cell constants a =. 6441 (2) nm, b = 2.0599(3) nm, c=. 0719(2) nm. 

Fluorescence Properties of Rare Earth Complexes Containing 1,8-Naphthyridines... 

Summary of structural data on rare earth complexes containing halogen oxoanions. ... 

The rare earth ions belong to class (a) in the Ahrland, Chatt and Davies (1958) classification or to the hard acid class in the Pearson (1963) designation. Ions in this class bond to hard bases, primarily those which contain oxygen and nitrogen as the donor atoms, and bond only weakly to the soft bases which contain, for example, sulfur or phosphorous as the donor atoms. This means that by far the majority of rare earth complexes contain ligands which utilize at least one oxygen atom. As a result, the variety of types of complexes which can be formed easily with the rare earth ions is more restricted than that which is formed with the d-transition elements. 

Q.D. Ling, E.T. Kang, K.G. Neoh, and W. Huang, Synthesis and nearly monochromatic photoluminescence properties of conjugated copolymers containing fluorene and rare earth complexes, Macromolecules, 36 6995-7003, 2003. 

The first systematic studies of polyoxometalate—rare-earth complexes were published in 1971 (Peacock and Weakley, 1971a, 1971b). Two classes of polytungstate complexes were described and these can now be seen to have common structural features. The complexes of Y, La, Ce(III and IV), Pr, Nd, Sm, Ho, Er, and Yb in which R W = 1 10 were readily formed by reaction of WO - with the appropriate rare-earth salt, but are stable only within the pH range 5.5-8.5. More recent 183W-NMR studies (Inoue et al., 2003) indicate that in solution the anions containing the heaviest R (Tm, Yb and Lu) are partially decomposed. 

The chemical composition of rare earth complexes cannot by itself reveal the coordination number of the central metal ion. There are many complexes containing hydrated water molecules and coordinated water molecules. The nitrilotriacetic acid (NTA) complexes of Pr and Dy have the formulae PrNTA 3H2O and DyNTA 4H2O, respectively. The praseodymium complex is a nine-coordinate system with one molecule of water in the hydrated form [12] and the dysprosium complex is eight-coordinate with two molecules of water of hydration [13]. These structures cannot be predicted from the composition of the complexes. The complex Nd(N03>3 4DMSO is ten-coordinate [14] since the nitrate... 

Figure 2.30 Representation of the asymmetric unit of [Nd(L )4(H20)][(TTF—CH=CH—Py+)] 2-The radical cation donors are drawn as balls and sticks the paramagnetic anionic coordination complexes of Nd(III) are drawn as capped sticks [23d], (Reprinted with permission from F. Pointillart, O. Maury, Y. Fe Gal, S. Golhen, O. Cador and F. Ouahab, 4-(2-Tetrathiafulvalenyl-ethenyl)pyridine (TTF—CH=CH—py) radical cation salts containing poly(P-diketonate) rare earth complexes synthesis, crystal structure, photoluminescent and magnetic properties, Inorganic Chemistry, 48, 7421-7429, 2009. 2009 American Chemical Society.)...

Figure 2.53 Molecular structure of [Nd(L )3(Fc2phen)] [33]. (Reprinted with permission from Y.F. Yuan, T. Cardinaels, K. Lunstroot et al, Rare-earth complexes of ferrocene-containing ligands visible-light excitable luminescent materials, Inorganic Chemistry, 46, 5302-5309, 2007. 2007 American Chemical Society.)...

Proton NMR Shifts. The proton NMR spectra for several diamagnetic rare earth complexes of OMPA are shown in Figure 3, and the data are tabulated in Table III. The proton NMR spectrum of free OMPA contains a doublet which is caused by coupling between the phosphorus... 

A number of volatile rare earth chelates containing the ligands, l,l,l,2,2,3,3-heptafluoro-7,7-dimethyl-4,6-octanedi-one, [H(fod)], and 2,2,6,6-tetramethyl-3,5-heptanedione, [H(thd)] have been synthesized and investigated. The fod complexes are more volatile than other known compounds of the lanthanide elements. The fod complex of Sc(III) and the lanthanide thd compounds are anhydrous. The fod chelates of Y(III) and the lanthanides are isolated as hydrates but can easily be dehydrated in vacuo over P Oio. Gas chromatographic and thermo gravimetric data reveal that the volatilities of the complexes increase as the ionic radii of the metal ions become smaller. 

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