Crystal Structure of a Luminescent Europium(III) Complex: Probing the Active Species in Dissociation-Enhanced Lanthanide Fluoroimmunoassay

1993 ◽  
Vol 46 (4) ◽  
pp. 577 ◽  
Author(s):  
CM Dearie ◽  
RM Dyson ◽  
TW Hambley ◽  
GA Lawrance ◽  
M Maeder ◽  
...  

The highly luminescent complex [ Eu ( fnac )2( topo )2(NO3)], which contains the two component ligands [ fnac, the anion of 4,4,4-trifluoro-1-(2-naphthyl)butane-1,3-dione, and topo, trioctylphosphine oxide] of the luminescent species in the dissociation-enhanced lanthanide fluoroimmunoassay method, has been prepared and defined by an X-ray crystal structure analysis. The complex crystallizes in the Ccmm space group, a 17.064(18), b 30.254(21) and c 16.391(4) Ǻ, Z = 4, and a single-crystal X-ray structure determination refined to R 0.056 for 1772 independent 'observed' reflections. The complex exhibits a dodecahedral EuO8 structure with bidentate nitrate ion [ Eu -O 2.512(10)Ǻ], two bidentate substituted acetylacetonate ( fnac )[ Eu -O 2.379(9), 2.400(9)Ǻ], and two monodentate long-chain phospine oxide ( topo ) ligands [ Eu -O 2.295(9)Ǻ].

2012 ◽  
Vol 76 (3) ◽  
pp. 517-534 ◽  
Author(s):  
A. R. Kampf ◽  
S. J. Mills ◽  
M. S. Rumsey ◽  
J. Spratt ◽  
G. Favreau

AbstractMatulaite was first described by Moore and Ito (1980) from the Bachman mine, Hellertown, Northampton County, Pennsylvania, USA. Its ideal formula was reported as CaAl18(PO4)12(OH)20·28H2O, based on wet-chemical analysis. Re-examination of both existing cotype specimens of matulaite revealed no material matching the powder or single-crystal X-ray diffraction data reported for the species. Other samples examined from the type locality, as well as from the LCA pegmatite in North Carolina, USA, and Fumade, Tarn, France, provided material crystallographically consistent with matulaite: P21/n, a = 10.604(2), b = 16.608(4), c = 20.647(5) Å , b = 98.848(7)° and Z = 4. Electron microprobe and crystal structure analysis of newly studied material from the type locality showed the ideal formula of matulaite to be Fe3+ Al7(PO4)4(PO3OH)2(OH)8(H2O)8˙8H2O. The chemical composition reported by Moore and Ito (1980) was most probably determined on a mixture of mostly kobokoboite and afmite, with lesser amounts of crandallite. As there is no matulaite on any of the existing cotype specimens of the species, the two specimens used to obtain the new chemical analyses, powder and single-crystal X-ray diffraction data and the structure determination are designated as neotypes. The neotypes have also been used to obtain crystal morphology and new measurements of the physical and optical properties of the species. The neotypes and new data have been approved by the CNMNC, proposal 11-F. The crystal structure of matulaite contains seven-member chain segments of AlO6 octahedra decorated by PO4 tetrahedra. The PO4 tetrahedra also link to isolated FeO6 octahedra, resulting in a 'pinwheel' Fe(PO4)6 group. The linkage of octahedra and tetrahedra defines a thick layer parallel to {001}. The only linkage between layers is via hydrogen bonding to interlayer water molecules.


2008 ◽  
Vol 63 (5) ◽  
pp. 530-536 ◽  
Author(s):  
Olaf Reckeweg ◽  
Francis J. DiSalvo

Single crystals of Ca11N6[CN2]2 (dark red needles, tetragonal, P42/mnm (no. 136), a = 1456.22(5), and c = 361.86(2) pm, Z = 2), Ca4N2[CN2] (transparent yellow needles, orthorhombic, Pnma (no. 62), a = 1146.51(11), b = 358.33(4), and c = 1385.77(13) pm, Z = 4) and Ca[CN2] (transparent, colorless, triangular plates, rhombohedral, R3̅m (no. 166), a = 369.00(3), and c = 1477.5(3) pm, Z = 3) were obtained by the reaction of Na2[CN2], CaCl2 and Ca3N2 (if demanded by stoichiometry) in arc-welded Ta ampoules at temperatures between 1200 - 1400 K. Their crystal structures were re-determined by means of single crystal X-ray structure analyses. Additionally, the Raman spectra were recorded on these same single crystals, whereas the IR spectra were obtained with the KBr pellet technique. The title compounds exhibit characteristic features for carbodiimide units with D∞h symmetry (d(C-N) = 121.7 - 123.8 pm and ∡ (N-C-N) = 180°). The vibrational frequencies of these units are in the expected range (Ca11N6[CN2]2: νs = 1230, νs = 2008; δ = 673/645/624 cm−1; Ca4N2[CN2]: νs = 1230, νs = 1986; δ = 672/647 cm−1; Ca[CN2]: νs = 1274, νs = 2031, δ = 668 cm−1). The structural results are more precise than the previously reported data, and with the newly attained Raman spectrum of Ca11N6[CN2]2 we correct data reported earlier.


1987 ◽  
Vol 40 (3) ◽  
pp. 625 ◽  
Author(s):  
HD Becker ◽  
BW Skelton ◽  
AH White

Hydrolysis of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone in aqueous ethanol gives the deep-red coloured ammonium salt of a monocyano-dichloro-monohydroxy-benzoquinone which crystallizes in the tetragonal space group I41 /a, a 20.832(5), c 8.618(2) �, Z 16. Single-crystal X-ray structure determination (R 0.036 for 1185 'observed' reflections) show the presence of ammonium cations forming hydrogen bonds in the lattice alternatingly with the tautomeric anion of 2-cyano-5,6-dichloro-3-hydroxy-1,4-benzoquinone and 3-cyano-5,6-dichloro-4-hydroxy-1,2-benzoquinone.


2004 ◽  
Vol 59 (5) ◽  
pp. 567-572 ◽  
Author(s):  
Claus Mühle ◽  
Andrey Karpov ◽  
Jürgen Nuss ◽  
Martin Jansen

Abstract Crystals of K2Pt(CN)4Br2, K2Pt(CN)4I2 and K2Pt(CN)4Cl2 ·2H2O were grown, and their crystal structures have been determined from single crystal data. The structure of K2Pt(CN)4Cl2 has been determined and refined from X-ray powder data. All compounds crystallize monoclinicly (P21/c; Z = 2), and K2Pt(CN)4X2 with X = Cl, Br, I are isostructural. K2Pt(CN)4Cl2: a = 708.48(2); b = 903.28(3); c = 853.13(3) pm; β = 106.370(2)°; Rp = 0.064 (N(hkl) = 423). K2Pt(CN)4Br2: a = 716.0(1); b = 899.1(1); c = 867.9(1) pm; β = 106.85(1)°; R(F)N′ = 0.026 (N’(hkl) = 3757). K2Pt(CN)4I2: a = 724.8(1); b = 914.5(1); c = 892.1(1) pm; β = 107.56(1)°; R(F)N′ = 0.025 (N’(hkl) = 2197). K2Pt(CN)4Cl2 ·2H2O: a = 763.76(4); b = 1143.05(6); c = 789.06(4) pm; β = 105.18(1)°; R(F)N′ = 0.021 (N’(hkl) = 2281). Raman and infrared spectroscopy data are reported.


1977 ◽  
Vol 30 (12) ◽  
pp. 2723 ◽  
Author(s):  
EN Maslen ◽  
CL Raston ◽  
AH White

The crystal structure of the title compound, CZOH3803 [compound (1) in ref.'], has been determined by single-crystal X-ray diffraction at 295(1) K and refined by least squares to a residual of 0.045 for 954 'observed' reflections. Crystals are monoclinic, P2', a 9.281(2), b 17.798(6), c 6.417(1) A, B 93.81(3)", Z 2. The structure determination establishes the relative configuration of the chiral centres within the 14-membered macrocyclic ring and shows the double bond to have the unusual (Z) configuration.


Sign in / Sign up

Export Citation Format

Share Document