E. Forsellini

Preparation, crystal and molecular structure of GdCl3(18-crown-6)·EtOH

Abstract The structure of the title compound has been determined from single-crystal X-ray analysis. The triclinic cell has dimensions a = 13.225(3), b = 10.246(2), c = 8.283(2) A, α = 112.1(1), β = 101.9(1) and γ = 85.0(1)°, space group P 1 , Z = 2. The structure was refined by least square methods to the conventional R value 0.032 for 2791 observed reflections. The molecule is formed by [GdCl 2 EtOH(18-crown-6)] + cations and Cl − anions. In the cation the crown ether ligand, which includes the Gd ion, is folded away from the side where a chlorine and the ethanolic oxygen are coordinated to the metal ion; a second chloride ion is coordinated on the opposite side.

Structural studies on actinides carboxylates—VI [1]: Crystal structures of strontium uranyldimalonate trihydrate and barium uranyldimalonate trihydrate

Abstract SrUO2(C3H2O4)2 · 3H2O and BaUO2 (C3H2O4) · 3H2O are isostructural. They crystallize in the orthorhombic system space group Pbca with eight molecules in cells of dimensions a = 16.729 (8), b = 23.247 (11) and c = 6.848 (5) A and a = 17.063 (9), b = 23.604 (12) and c = 6.885 (5) A, respectively. The structures were solved by the heavy-atom technique and refined with full-matrix least-squares to the R values of 0.043 and 0.046, respectively. The coordination geometry around the uranium atom is a pentagonal bipyramid with the malonates behaving as bidentate or terdentate ligands to the uranium atoms forming polymeric chains [UO2(C3H2O4)2]n2n− parallel to c. The space between the uranyl dimalonate chains is occupied by the oxygen atoms belonging either to the water molecules or to the carboxylic groups. Each polyhedron shares two edges forming columns running in the same direction as the uranyl chains and connecting them four by four.

The crystal and molecular structure of an isomer of chloro [1,9-bis(2-pyridyl)-2,5,8-triazanonane] cobalt(III), tetrachlorozincate(II), [Co(picdien)Cl]ZnCl4

Abstract The structure of the title compound has been determined by counter data. The crystals are orthorhombic, space group P bca , with a = 16.363(7), b = 18.382(8), c = 14.940(6) A, Z = 8. The structure has been defined by full-matrix least-squares to a final conventional R value of 0.092 ( R w = 0.081 ). The coordination geometry of the complex cation is near regular octahedral, with the pentadentate picdien ligand present in the α,β configuration and with a Cl trans to an ‘angular’ secondary nitrogen. Only two, i.e. , one ‘angular’ and the ‘flat’ of the three secondary nitrogen atoms of the picdien ligand exhibit chirality and it is opposite. The absolute configuration of the complex can be designed as Δ-α, β-R (or Λ-α, β-S). The ZnCl 4 anion assumes a distorted tetrahedral configuration.

Crystal and molecular structure of chloro[1,11-bis(2-pyridyl)2,6,10-triazaundecane]cobalt(III) tetrachlorocobaltate(II) hemihydrate, [Co(picditn)Cl] CoCl4·H2O

The structure of the title compound has been determined by counter data. The crystals are orthorhombic, space group P212121 with a = 16.069(8), b = 13.215(6), c = 11.490(5) A, Z = 4. The structure has been refined by full-matrix least-squares to a final conventional R value of 0.049. The coordination geometry of the complex cation is near regular octahedral, with the pentadentate ligand present in the α,β configuration and with a Cl trans to an ‘angular’ secondary nitrogen. The absolute configuration of the complex ion can be designed as Λ while the two optically active N(2) and N(4) are R a;nd S respectively.

Crystal structure of tris(2-pyridylthio-2-pyridinium)pentaisothiocyanato-dioxouranate(VI)

SummaryThe crystal structure of [DPSH]3+[UO2[NCS)5]3− (DPSH = 2 pyridylthio-2-pyridinium) has been determined by standard methods using diffractometer data. Crystals are monoclinic, space groupP21/a, witha=33.16 (3),b=16.68(2),c=7.85(1) Å, andβ=97.3(1)∘; Dc=1.65 g · cm−3 for Z=4. The structure has been refined to R=5.8% by least squares methods. Five thiocyanate groups are equatorially bonded to the linear uranyl group. The mean of the five U-N, N-C, and C-S bond distances are 2.45, 1.17, and 1.59 Å respectively. The protonated DPS molecules have the N,N-inside conformations.

The crystal and molecular structure of an isomer of chloro(1,5,8,11,14-pentaazacyclohexadecane) cobalt(III), diperchlorate, [Co(16-[ane]-5)Cl] (ClO4)2

Abstract The structure of the title compound has been determined by counter data. The crystals are orthorhombic, space group P n 2 1 a with a = 14.317(7), b = 13.484(7) and c = 10.361(6) A, Z = 4. The structure has been refined by full-matrix least-squares to a final conventional R value of 0.085 (Rw = 0.083). The geometry of the complex action is a relatively undistorted octahedron with a chlorine atom trans to an ‘angular’ secondary nitrogen of the pentadentate 16-[ane]-5 ligand. Within the ligand the six-membered ring assumes a ‘chair’ conformation, while all five-membered rings are ‘gauche’. Only one, i.e., the ‘angular’ N(1) trans to Cl(1) of the five secondary nitrogen atoms of 16-[ane]-5 does not exhibit chirality. The two ‘flat’ nitrogens have opposite chirality as do the two remaining ‘angular’ nitrogens. The ClO 4 anions assume a distorted tetrahedral configuration.

Conformational differences in dioxouranium(VI) coordination compounds: Crystal structure of the chloroform adduct of N,N′-bis-salicylidene-1,5-diamino-3-oxapentane-dioxouranium(VI)

Abstract The title compound (UO 2 -saloden·CHCl 3 ) crystallizes in an orthorhombic system, space group Cmc 2 1 with a = 16.938(6), b = 12.440(5) and c = 10.662(4) A , Z = 4 . The coordination geometry of the uranium atom is bipyramidal pentagonal with the ligand pentadentate in the equatorial plane of the uranyl ion. The chloroform molecule does not interact directly with the ligand. The IR spectral data are also discussed.

The crystal and molecular structure of an isomer of Bromo [1,9-bis(2-pyridyl) 2,5,8-triazononane] cobalt(III), perchlorate, [Co(picdien)Br](ClO42and that of an isomer of nitro[1,9-bis(2-pyridyl)2,5,8-triazanonane]cobalt(III), perchlorate, [Copicdien)(No2)](ClO4)2

Abstract The structure of an isomer of bromo [1,9-bis(2-pyridyl)2,5,8-triazanonane] cobalt(III), perchlorate, [Co(picdien)Br](ClO 4 ) 2 , (I) and that of an isomer of nitro [1,9-bis(2-pyridyl)2,5,8-triazanonane]cobalt(III), perchlorate, [Co(picdien)(NO 2 )](ClO 4 ) 2 , (II), was determined by counter data. Crystal data are as follows: (I), a = 21.242(9), b = 21.732(9), 10.015(5) A , orthorhombic, P b c a, Z = 8; (II), a = 10.062(5), b = 28.553(9), c = 7.894(4) A , β = 97.9(1)°, monoclinic, I c, Z = 4. Full matrix least-squares refinement converged at R = 0.064, (I), and R = 0.068, (II). The coordination geometry of both complex cations is near regular octahedral, with the pentadentate picdein ligand present in the α, β configuration. The absolute configuration of (I) can be designed as Δ-α, β-R (or Λ-α, β-S) whereas that of (II) is Δ-α, β-S (or Λ-α, β-R). The ClO 4 anions assume a distorted tetrahedral configuration.

The crystal and molecular structure of an isomer of bromo[1,9-bis(2-pyridyl)2,5,8-triazanonane] cobalt(III) perchlorate, [Co(picdien)Br][ClO4]2

Abstract The structure of an isomer of bromo[1,9-bis(2-pyridyl)2,5,8-triazanonane] cobalt(III) perchlorate, [Co(picdien)Br][ClO4]2 has been determined by counter data. The crystals are monoclinic, space group P21/a with a = 10.263(5), b = 27.845(9), c = 7.888(4) A, β = 97.4(1)°, Z = 4, Do = 1.84, Dc= 1.85 g cm−3. The structure has been refined by full-matrix least-squares to a final conventional R value of 0.073 (Rw = 0.075) for 1664 reflections with I ⩾ 2.5σ (I). The coordination geometry of the complex cation is near regular octahedral, with the pentadentate picdien ligand present in the α,β configuration and with a Br trans to an ‘angular’ secondary nitrogen. Only two, i.e., one ‘angular’ and the ‘flat’ of the three secondary nitrogen atoms of the picdien ligand exhibit chirality and it is the same. The absolute configuration of the complex can be designed as Δ-α, β-S (and Λ-α,β-R). The ClO4 anions assume a distorted tetrahedral configuration.

The crystal and molecular structures of the N,N’-diisopropylbutyramide (DIPIBA) and N,N-dicyclohexylacetamide (DCA) complexes [Th(NCS)4(DIPIBA)3] and [Th(NCS)2Cl2(DCA)3]

The X-ray crystal structures of [Th(NCS) 4 (DIPIBA) 3 ] ( 1 ) [DIPIBA Me 2 CH CON(CHMe 2 ) 2 ] and [Th(NCS) 2 Cl 2 (DCA) 3 ]( 2 ) [DCA MeCON(cycloC 6 H 11 ) 2 ] have been determined from three-dimensional X-ray diffraction data. The different steric constraints of the ligand are not sufficient for different coordination geometries. In 1 and 2 the coordination polyhedron about the seven-coordinate thorium atom is a pentagonal bipyramid geometry which is becoming rather common for thorium(IV) compounds. In these compounds two chlorine ( 2 ) and two thiocyanate ( 1 ) anions are in axial positions with a significant shortening of the axial Th—NCS bonds with respect to the equatorial ones, while in the equatorial plane a neutral ligand lies between two anionic ligands, the remaining coordination positions being occupied by two other neutral ligands. The average bonding distances are Th O = 2.34(1)A, Th N ax = 2.42(1) and Th N eq = 2.46(1)Ain 1 , and Th O = 2.357(5), Th N eq = 2.479(6) and Th Cl ax = 2.695(3)Ain 2.