Structural Systematics of Rare Earth Complexes. XIII (‘Maximally’) Hydrated (Heavy) Rare Earth Nitrates

1999 ◽  
Vol 52 (6) ◽  
pp. 497 ◽  
Author(s):  
David L. Kepert ◽  
Peter C. Junk ◽  
Brian W. Skelton ◽  
Allan H. White
Keyword(s):  
Rare Earth ◽  
The Other ◽  
Water Molecules ◽  
Bidentate Ligands ◽  
X Ray ◽  
Rare Earth Nitrates ◽  
Triclinic Phase ◽  
Cell Dimensions ◽  
Structure Determinations ◽  
Coordinated Water

Room-temperature single-crystal X-ray structure determinations are known for a number of ‘maximally hydrated" nitrates of, in particular, the lighter lanthanoid elements; in all cases, all nitrates coordinate as O,O′-bidentate ligands so that the series may be represented at the outset as Ln(O2NO)3.x H2O. Two distinct triclinic P 1 hexahydrate phases of similar cell dimensions are recognized, the most distinctive distinguishing feature being that in the La, Ce phase the 11-coordinate Ln is surrounded by three O,O′-bidentate nitrate and five O-unidentate water molecule ligands; the domain of the other, with four coordinated water molecules, extends from Ln = Pr to Ln = Dy (inclusive of Y). At local ambience, we have crystallized heavier members of the series as pentahydrates, isomorphous with the previously characterized Ln = Eu example, also containing a molecule of the form [Ln(O2NO)3(OH2)4] (with a molecule of water of crystallization), but a different stereoisomer to that found in the Ln = Pr(-)Dy array. Structure determinations are recorded for Ln = Dy, Er, Yb, conventional R on |F| 0·042, 0·034, 0·029 for No = 3858, 3980, 3935 independent ‘observed’ (I > 3σ(I)) diffractometer reflections. For Ln = Lu a new tetrahydrate phase is described, monoclinic P21/n, a 7·379(7), b 10·364(5), c 14·26(1) Å, β 96·09(7)°, Z = 4, R 0·048 for No 2324, together with a new triclinic P 1 trihydrate, a 12·591(4), b 12·144(3), c 7·355(2) Å, α 80·22(2), β 77·68(3), γ 62·30(2)°, Z = 4, R 0·051 for No 4552. In both of the latter, Lu is nine-coordinate, with three bidentate nitrate groups and three coordinated water molecules; remarkably, the two independent molecules of the asymmetric unit in the triclinic phase are distinct isomers, one having the water molecules fac, derivative of the 10-coordinate array of the Pr(-)Yb series with quasi-3 symmetry, while the other, like that in the monoclinic phase, is mer.

Structural Systematics of Rare Earth Complexes. XI (‘Maximally’) Hydrated Rare Earth(III) Trifluoro- and Trichloro-acetates

1999 ◽  
Vol 52 (6) ◽  
pp. 459 ◽  
Author(s):  
Cameron J. Kepert ◽  
Lu Wei-Min ◽  
Peter C. Junk ◽  
Brian W. Skelton ◽  
Allan H. White
Keyword(s):  
Rare Earth ◽  
Single Crystal ◽  
Room Temperature ◽  
Linear Polymer ◽  
The Other ◽  
Water Molecules ◽  
X Ray ◽  
Metal Atoms ◽  
Carboxylate Groups ◽  
Structure Determinations

Room-temperature single-crystal X-ray structure determinations carried out on ‘maximally’ hydrated rare earth(III) trifluoroacetates, Ln(tfa)3.x H2O, crystallized at room temperature, show the Ln = La, Ce adducts to be isomorphous and monoclinic, P 21/c, a ≈ 11·9, b ≈ 12·8, c ≈ 9·8 8 Å, β ≈ 103·7°, Z = 4; they are trihydrates. The Ln = Pr, Lu (and, implicitly, intermediate Ln) adducts are also monoclinic, P 21/c, Z = 4, and trihydrates, but of a different polymorph, with a ≈ 9·2, b 18·8, c ≈ 9·8 Å, β ≈ 114°. For the four determinations, conventional R values on |F| were 0·038, 0·032, 0·036, and 0·034 for No 2952, 4821, 4544, and 4092 independent ‘observed’ (I > 3σ(I)) diffractometer reflections respectively. The Ln = La, Ce adducts are two-dimensional polymers, the sheets parallel to the bc plane; the other systems are binuclear, the two metal atoms being linked by four bridging carboxylate O-tfa-O′ ligands. In both structural types, the metal atoms are eight-coordinate, but differ in the number of water molecules (2 cf. 3) in the O8 array. Extension of previous studies by single-crystal X-ray methods on the structural characterization of trivalent rare earth trichloroacetates, ‘maximally’ hydrated at local ambience, Ln(tca)3.x H2O, suggests the following arrays to be prevalent. The Ln = La adduct is a pentahydrate, monoclinic, P21/c, a 5·636(7), b 22·454(4), c 16·58(1) Å, β 90·52(8)°, Z = 4 f.u., R 0·035 for No 4154. The compound is a linear polymer along a, successive nine-coordinate La (separated by a) being linked by three O-tca-O′ bridging ligands at the opposite faces of a tricapped trigonal prismatic array, the equatorial sites being filled by water molecules. The Ln = Ce adduct is a trihydrate, monoclinic, P 21/c, a 10·071(2), b 22·973(2), c 20·222(5) Å, b 119·48(2)°, Z= 8 f.u., R 0·050 for No 5019. The array is also linear polymeric, but with successive Ce being linked alternately now by sets of two and then four O-tca-O′ bridging carboxylates along b, the Ln = Ce coordination number being diminished (relative to La) to eight with the coordination of two water molecules to each metal. Ln = Pr, Lu (and, presumptively, intermediate Ln) are dihydrates, triclinic, P 1, a ≈ 11·70, b ≈ 12·8, c ≈ 15·3 Å, α ≈ 71, β ≈ 77·85, γ ≈ 65·5°, Z = 4 f.u., R 0·056, 0·059 for No 5650, 5398. The array is a linear polymer, similar to that of the Ln = Ce adduct but alongside the bridging acetate pair one of the water molecules now bridges, resulting in a stepped Ln 1 array (along c) rather than a quasi-straight one as is found for the Ln = Ce (and La) adduct. Structure determinations are also recorded for rare earth(III) trichloroacetate ethanol trisolvates, Ln(tca)3.3EtOH. Adducts of Ln = La, Yb (and, implicitly, intermediate Ln) are isomorphous, triclinic, P 1, a ≈ 12, b ≈ 11·8, c ≈ 11·4 Å, α ≈ 114, β ≈ 100, γ ≈ 104°, Z = 2 f.u., R 0·056, 0·050 for No 3843, 4171. The complexes are centrosymmetric dimers [(EtOH)3(tca-O)Ln(O-tca-O′)4Ln(O-tca)(HOEt)3], the two metal atoms being linked by four O-tca-O′ bridging carboxylate groups; the metal atoms are eight-coordinate, the other four sites being occupied by four oxygen atoms from unidentate ethanol and carboxylate moieties. Bis(bis(2-pyridyl)aminium) bis(diaquatetrakis(trichloroacetato)lanthanate(III)), 2(dpaH+) [(H2O)2-(tca-O)(tca-O,O′)2La(O-tca-O′)2La(O,O′-tca)2(O-tca)(OH2)2]2-, is triclinic, P 1, a, 13·901(2), b 13·764(3), c 10·073(2) Å, α 104·04(2), β 108·93(2), γ 101·50(2)°, Z = 1 binuclear f.u., R 0·045 for No 4999. The anion is binuclear, the two nine-coordinate lanthanum atoms being linked by a pair of bridging O-carboxylate-O′ groups. The other seven sites of the LaO9 array are occupied by a pair of O,O′ -chelating and one O-unidentate carboxylate groups and a pair of water molecules.

Synthesis, Fluorescence Properties of 2-Acetyl-2'-Chloroacetanilide with Rare Earth Nitrates Complexes

2011 ◽  
Vol 219-220 ◽  
pp. 574-577
Author(s):  
Xi Shi Tai ◽  
Lin Tong Wang
Keyword(s):  
Rare Earth ◽  
Rare Earth Ions ◽  
Fluorescence Properties ◽  
Water Molecules ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Rare Earth Nitrates ◽  
Ft Ir ◽  
Coordinated Water ◽  
The Eu

The reaction of 2-acetyl-2'-chloroacetanilide (L) with rare earth nitrates in CH3CH2OH followed by recrystallization in CH3CH2OH gave rise to colorless block crystals materials. The complexes and ligand were analyzed by FAB, elemental analysis(C, H, N), FT-IR spectra, TG-DTA, molar conductivity and X-ray single crystal diffraction. The fluorescence properties of ligand and the Eu (Ⅲ) complex also have been investigated. The results of crystal structure and spectral data show that the rare earth ions coordinated with oxygen and nitrogen atoms of the ligand, the nitrate and coordinated water molecules. The Eu (Ⅲ) complex material shows characteristic red emissions.

Polar potassium rare earth nitrates K2[RE(NO3)5(H2O)2] (RE = La, Ce, Pr and Nd). I. Crystal growth and crystal structures

2000 ◽  
Vol 33 (2) ◽  
pp. 372-379 ◽  
Author(s):  
P. Held ◽  
H. Hellwig ◽  
S. Rühle ◽  
L. Bohatý
Keyword(s):  
Rare Earth ◽  
Optical Quality ◽  
Rare Earth Ions ◽  
Water Molecules ◽  
Hard Sphere Model ◽  
Stoichiometric Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rare Earth Nitrates ◽  
Evaporation Technique

Using a standard evaporation technique at 311 K, large single crystals of the polar orthorhombic potassium rare earth nitrates K2RE(NO3)5.2H2O, where RE = La, Ce, Pr or Nd, of optical quality and dimensions up to 5 × 5 × 4 cm, were grown from aqueous solutions containing a stoichiometric ratio of potassium and rare earth ions (K:RE = 2:1) and a surplus of nitric acid. Detailed structural and crystal chemical analyses of all four isomorphic compounds based on single-crystal X-ray diffraction data were carried out [space groupFdd2;Z= 8; La compound:a= 11.2814 (6),b= 21.480 (1),c= 12.2589 (4) Å,R= 0.94%; Ce compound:a= 11.263 (3),b= 21.404 (3),c= 12.230 (4) Å,R= 1.92%; Pr compound:a= 11.213 (2),b= 21.392 (4),c= 12.204 (2) Å,R= 1.58%; Nd compound:a= 11.197 (1),b= 21.378 (1),c= 12.195 (1) Å,R= 1.55%]. The main structural feature is the diaquapentanitratolanthanide(III) group, [RE(NO3)5(H2O)2]2−, as stated earlier by Eriksson, Larsson, Niinistö & Valkonen [Acta Chem. Scand. Ser. A, (1980),34, 567–572] for the La compound. The rare earth atoms are surrounded by 12 O atoms, two of which belong to water molecules, the remaining ten belonging to five bidentate nitrate groups. The coordination polyhedron [REO12] is a distorted icosahedron; its geometry is discussed using a simple hard-sphere model.

Structural Systematics of Rare Earth Complexes. II. Structural Characterization of Lanthanoid(III) Picrate Hydrates: the Triclinic P1, 11.5 Hydrates of the Later Rare Earths and Yttrium

1994 ◽  
Vol 47 (2) ◽  
pp. 339 ◽  
Author(s):  
JM Harrowfield ◽  
WM Lu ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Aqueous Solution ◽  
Rare Earth ◽  
Structural Characterization ◽  
Complex Cation ◽  
Water Molecules ◽  
Complex Ions ◽  
X Ray ◽  
Lattice Water ◽  
Structure Determinations

Picrates of dysprosium(III), holmium(III), erbium(III), thulium(III), ytterbium(III), lutetium(III) and yttrium(III) have been found to crystallize as needles from aqueous solution, seemingly best described as 11.5 hydrates. Single-crystal X-ray structure determinations have been performed at c. 295 K on the Dy , Er , Lu and Y species, and show them to be isomorphous , triclinic, Pī , a 20.043(7) → 20.019(5), b 11.533(2) → 11.471(2), c 8.1567(7) → 8.1538(8) Ǻ, α 88.60(1) → 88.40(1), β 87.12(2) → 87.06(1), γ 75.07(2) → 75.05(2)°, V 1819 → 1807 Ǻ3 ( Dy → Lu; the Y and Er values are intermediate). Complex ions [ Ln ( pic )(OH2)7]2+ are observed, with a pair of uncoordinated picrate anions and 4.5 lattice water molecules; this result is in contrast to that of the monoclinic, P 21/c, series found for La → Pr and Nd → Tb, in which the complex cation contains two picrate anions.

Synthesis, Spectral Properties of Methyl-2-Pyridyl Ketone Benzoyl Hydrazone and its Complexes with Rare Earth Nitrates

2011 ◽  
Vol 219-220 ◽  
pp. 565-568 ◽  
Author(s):  
Xi Shi Tai ◽  
Lin Tong Wang
Keyword(s):  
Rare Earth ◽  
Mass Spectra ◽  
Uv Spectra ◽  
Water Molecules ◽  
Keto Form ◽  
Rare Earth Nitrates ◽  
Coordinated Water ◽  
Luminescent Spectra ◽  
Benzoyl Hydrazone ◽  
Oxygen Atoms

A new schiffbase ligand, methyl-2-pyridyl ketone benzoyl hydrazone (L), and its complexes with rare earth nitrates have been synthesized. These new complexes with the general formula of Ln(L)2(NO3)3·nH2O(where Ln = La, n = 5.5; Ce, Pr, n = 5; Nd, Eu, n = 4 ) were characterized by mass spectra, elemental analysis, IR spectra, thermal analysis, UV spectra, molar conductivity and luminescent spectra. All the complexes are stable in air. The results show that the lanthanide ion in each complex are coordinated by oxygen and nitrogen atoms of the ligand, the oxygen atoms of the nitrate and coordinated water molecules. The amide-oxygen atoms of L coordinate to the Ln ions in its keto-form. Tentative structures for the complexes have been proposed.

X-Ray and Optical Data for a Rare Earth–Poor Eudialyte from the North–Central Alaska Range

1990 ◽  
Vol 5 (2) ◽  
pp. 89-92 ◽  
Author(s):  
Neil E. Johnson ◽  
Mickey E. Gunter ◽  
Diana N. Solie ◽  
Charles R. Knowles
Keyword(s):  
Rare Earth ◽  
Powder Diffraction ◽  
Weight Percent ◽  
Optical Data ◽  
Alaska Range ◽  
North Central ◽  
X Ray ◽  
The North ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

AbstractPowder X-ray and optical data have been recorded for a sample of exceptionally rare earth-poor eudialyte (Na12(Ca, REE)6(Fe2+,Mn,Mg)3Zr3(Zr,Nb)x[Si9O27−y(OH)y]2[Si3O9]2(C1,F)z, with x = 0. 1–0.9, y = 1–3 and z = 0.7–1.4) from a pegmatitic vein associated with the peralkaline Windy Fork granite in the north–central Alaska range. The eudialyte is uniaxial positive with ω= 1.6062(2), ε= 1.6138 (3) and microprobe analyses indicate that the sum of REE + Yis less than 0.1 weight percent. Refined unit cell dimensions are: a = 14.2572(4), c = 30.1338(27), Dx= 2.67, F30= 128 (0.006, 42), M20= 76. An indexed powder diffraction pattern is given.

Crystal Structure of Calcium Picrate Pentahydrate: A New Eight-Coordinate Stereochemistry for [M(bidentate)2(unidentate)4]

1979 ◽  
Vol 32 (2) ◽  
pp. 301 ◽  
Author(s):  
V Diakiw ◽  
TW Hambley ◽  
DL Kepert ◽  
CL Raston ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Water Molecule ◽  
Single Crystal ◽  
Title Compound ◽  
Lattice Site ◽  
The Other ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Triangular Face ◽  
X Ray

The crystal structure of the title compound, Ca(C6H2N307)2,5H2O, has been determined by single-crystal X-ray diffraction at 295(1) K and refined by least squares to a residual of 0.049 for 1513 'observed' reflections. Crystals are orthorhombic, Pmab, a 24.169(6), b l0.292(7), c 8.554(2) �, Z 4. The stereochemistry about the calcium has not been observed previously for the system [M(bidentate)2- (unidentate)4]; in the present structure, the calcium is coordinated by a pair of bidentate picrate ligands and the four water molecules in an array in which three of the water molecules occupy a triangular face of a square antiprism, the overall array having m symmetry. The remaining water molecule occupies a lattice site with no close interaction with the other species.

Synthesen und Kristallstrukturen von [PPh3Me]NO2 und [PPh3 Me]HCO2H2O / Syntheses and Crystal Structures of [PPh3Me]NO2 and [PPh3Me]HCO2H2O

1988 ◽  
Vol 43 (10) ◽  
pp. 1279-1284 ◽  
Author(s):  
Mervat El Essawi ◽  
H Gosmann ◽  
D Fenske ◽  
F Schmock ◽  
K Dehnicke
Keyword(s):  
Crystal Structure ◽  
Aqueous Solutions ◽  
Ir Spectra ◽  
Bond Angle ◽  
Water Molecules ◽  
Moist Air ◽  
Space Group ◽  
X Ray ◽  
Bond Lengths ◽  
Structure Determinations

Triphenylmethylphosphonium nitrite and formate have been prepared by the reaction of [PPh3Me]I with silver nitrite, and lead formate, respectively, in aqueous solutions. [PPh3Me]NO2 (1) forms pale yellow crystals, and [PPh3Me]HCO2·H2O (2) forms white crystals. Both compounds are soluble in water, ethanol, and dichloromethane. In moist air 2 is hydrated to yield [PPh3Me]HCO2·2H2O (3). The compounds were characterized by their IR spectra, 1 and 2 also by X-ray crystal structure determinations.[PPh3Me]NO2 (1): space group P21/n, Z = 4, 2088 independent observed reflexions, R = 0.062. Lattice dimensions (20 °C): a = 914.7(3), b = 1887.5(9), c = 1080.0(4) pm, β = 110.29(3)°. The compound consists of PPh3Me+ ions and NO2- anions with bond lengths of 114.2(6) pm and a bond angle of 124.1(7)°. [PPh3Me]HCO2·H2O (2): space group P21/n, Z = 4, 2973 independent observed reflexions, R = 0.069. Lattice dimensions (-20 °C): a = 931(2), b = 1558(3), c = 1281(2) pm, β = 105.9(1)°. The compound consists of PPh3Me+ ions and formate anions which form centrosymmetric dimeric units [HCO2·H2O]22- through hydrogen bridges of the water molecules. Bond lengths CO 122.4(4) and 120.9(4) pm. bond angle OCO 129.9(4)°.

A Pyrazine-Bridged Ni(II) Coordination Polymer

2002 ◽  
Vol 57 (11) ◽  
pp. 1191-1194 ◽  
Author(s):  
Chirantan Roy Choudhury ◽  
Subrata Kumar Dey ◽  
Sutapa Sen ◽  
Bappaditya Bag ◽  
Samiran Mitra ◽  
...  
Keyword(s):  
Coordination Polymer ◽  
Chain Structure ◽  
Water Molecules ◽  
Polymeric Complex ◽  
X Ray Diffraction ◽  
Intermolecular Hydrogen Bonds ◽  
X Ray ◽  
Elemental Analyses ◽  
Coordinated Water ◽  
Nitrate Anions

The single pyrazine-bridged polymeric complex {[Ni(pyz)(H2O)4](NO3)2.2H2O}n has been synthesised and characterised by elemental analyses, IR and UV-vis spectra, and a single-crystal X-ray diffraction study. The coordination around the Ni centre is perfectly octahedral. The Ni(H2O)4 coordination planes are bridged by pyrazine ligands forming an infinite chain structure. Two nitrate anions and two water molecules exist in the lattice and are linked by intermolecular hydrogen bonds to the coordinated water molecules.

Structural Systematics of 2/4-Nitrophenoxide Complexes of Closed-Shell Metal Ions. VII Acid Salts of the 4-Nitrophenoxides of Group 2

1998 ◽  
Vol 51 (8) ◽  
pp. 785 ◽  
Author(s):  
Jack M. Harrowfield ◽  
Raj Pal Sharma ◽  
Brian W. Skelton ◽  
Allan H. White
Keyword(s):  
Room Temperature ◽  
Calcium Salt ◽  
Three Dimensional ◽  
Closed Shell ◽  
The Other ◽  
X Ray ◽  
C 23 ◽  
Structure Determinations ◽  
Group 2 ◽  
Acid Salts

Room-temperature single-crystal X-ray structure determinations are recorded for a number of Group 2 4-nitrophenoxide acid salts, variously hydrated M(4-np)2.x(4-npH).yH2O. Ca(4-np)2.2(4-npH).8H2O is monoclinic, P 21/n, a 30·52(1), b 10·027(1), c 23·65(2) Å, β 116·3(5)°, Z = 8, conventional R on |F| being 0·058 for No 5092 independent ‘observed’ (I > 3s(I)) reflections. Sr(4-np)2.2(4-npH).8H2O, based on a subcell of the former, is monoclinic, P 21/c, a 15·576(5), b10·081(6), c 24·20(2) Å, β 117·99(5)° , Z = 4, R 0·054 for No 2908. Ba(4-np)2.2(4-npH).4H2O is orthorhombic, Fdd2, a 28·01(1), b 19·90(1), c 10·692(7)Å, Z = 8, R 0·028 for No 1967. The strontium array (and that of the calcium salt developed from it) may be represented as [(H2O)6Sr(4-npH.4-np)] (4-npH.4-np), a neutral ligand being unsymmetrically chelated to the strontium through the nitro group, with a quasi-parallel counter ion hydrogen-bonded to it by phenoxide confrontation. The other two 4-np residues make up a similar phenoxide-confronting pair (4-npH.4-np), the hydrogen being more intimately associated with one moiety. The barium salt is also an interesting array: the 10-coordinate barium lies on a crystallographic 2 axis, in an environment of two pairs of symmetry-related nitro-chelating ligand anions, and a pair of nitro-O coordinating neutral 4-npH ligands; the whole [(H2O)4Ba(4-np)2(4-npH)2] array may be envisaged as a single neutral (super)molecule. Hydrogen bonds between confronting phenoxides of the neutral 4-npH components of the parent and the 4-np- components of neighbouring molecules link the whole into a three-dimensional array.

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