Abstract. Mr= 1339, monoclinic, Pc, a= 9.593 (8), b = 17.481 (4), c= 15.816 (9)/k, fl= 97.3 (2) ° , Z= 2, V = 2631 (7)/k 3, D x = 1.69 Mg m -3, Cu Ka, 2 = 1.5418A, #=9.85mm -1, T=233(5) K, F(000)= 1304, final R =0.068 for 3417 observed reflections. The structural features generate a pseudosymmetry which renders the interpretation of the Fourier synthesis 0108-2701/83/121625-04501. 50 and refinement of the structure difficult. The uranyl group has no direct contact with the tetraphenylporphyrin (TPP) but presents a pentacoordination in the equatorial plane with five 0 atoms belonging to four trifluoroacetate groups. Hydrogen bonds connect the TPP and the bridging trifluoroacetic acid molecules (Htfa). © 1983 International Union of Crystallography C44H30N 4.2C 2HF30 2 . [UO 2 ] [C 2F302 ] 2Introduction. The present work is part of a research programme which is being carried out on uraniummacrocycle complexes. Single crystals were supplied by Drs G. Folcher and G. de Villardi (D~partement de Physicochimie, CEN-Saclay). The space group was determined photographically. After an unsuccessful trial of structure refinement with data collected at room temperature, the intensities were measured at 233 +5 K. Cell parameters at room temperature: a= 9.601(2), b= 17.473 (3), c= 15.988 (4)A, fl= 98.2 (2) °, V= 2655 (2)/~3. Experimental. A blue prismatic crystal (approximate dimensions 0.075 × 0.075 × 0.30 mm) with boundary faces {011} was selected and mounted along the [100] direction. Enraf-Nonius CAD-4 diffractometer equipped with a cooling device. Unit-cell dimensions and their estimated standard deviations obtained from a least-squares fit of the optimized diffractometer setting angles of 25 selected reflections. 3792 unique reflections (20 < 116 °) measured with the o3/20 scan technique [scan angle (1.5 + 0.14 tg0~°], graphite-monochromatized CuKct radiation; 366 considered unobserved [I< 1.5tr(I)]. Three standard reflections monitored every 100 measurements: no significant fluctuations. Data corrected for Lorentz-polarization effects; absorption corrections made taking crystal morphology into account. The position of the U atom was determined from a Patterson synthesis. The particular position of this atom and of the centre of the tetraphenylporphyrin added a non-existing twofold axis to the Fourier map, whose symmetry group was then P2/c. The problem of separating the real structure from its pseudosymmetry-generated image was difficult, since pseudosymmetric atomic positions were very close to those of the true atoms and the tendency to produce centrosymmetric phases was very strong. The noncentrosymmetric phases computed from the positions of the U atom and the C atoms of one phenyl group located in a Fourier map were used as the initial step to break the pseudosymmetry. The subsequent Fourier synthesis calculated with the 1790 highest I Fol using MULTAN78 (Main, Hull, Lessinger, Germain, Declercq & Woolfson, 1978) enabled us to locate the TPP and three tfa groups. At this stage the R value was 0.28. Difference maps...
The robustness of calix [4]arene dihydroxyphosphonic acid and its ubiquitous dimeric motif offers perspectives for predefined solid-state complexation with small molecules. In the current article, we describe the complex of calix[4]arene dihydroxyphosphonic acid with three different forms of bipyridyl ligand: 2,2′-bipyridine, 4,4′-bipyridine, and 1,2-bipyridylethane. A number of resemblances and differences in the interactions between the components in the complexes are pointed out. All the complexes are based on layers of calixarene dimers alternated with layers of bipyridyl molecules. While the complex with 2,2′bipyridine is encaged by a dense network of hydrogen bonds, the complexes with 4,4′-bipyridine and 1,2-bipyridylethane generate an extended 1-D ladder network. All of the complexes present π-π interactions between the bipyridyl moieties and the calix[4]arene dihydroxyphosphonic acid.
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