Allan White and Polypyridines: Extending the Lanthanide(III) Complex Series

2020 ◽  
Vol 73 (6) ◽  
pp. 434
Author(s):  
Simon A. Cotton ◽  
Jack M. Harrowfield ◽  
Lioubov I. Semenova ◽  
Brian W. Skelton ◽  
Alexandre N. Sobolev ◽  
...  
Keyword(s):  
Crystal Lattice ◽  
X Ray ◽  
Complex Series ◽  
Lanthanide Elements ◽  
Structure Determinations ◽  
Polypyridine Complexes ◽  
Overall Ratio ◽  
Coordinated Water ◽  
General Work ◽  
Selection Of

X-Ray structure determinations on 41 complexes of lanthanide(iii) halides, principally bromides, with 2,2′-bipyridine, 1,10-phenanthroline, and 2,2′:6′,2″-terpyridine provide a considerable extension to the earlier work of Allan White on such materials and a substantial extension of general work on polypyridine complexes of lanthanide halides. Complexes of 1:1, 1:2, and 2:4 metal-to-ligand composition have been characterised across a broad selection of the lanthanide elements, many of these species showing a higher overall ratio of ligand to lanthanide due to the incorporation of uncoordinated ligand within the crystal lattice. Although stacking of the aromatic entities is apparent in these adducts, in most instances H-bonding of unbound N to coordinated water appears to be the principal interaction involved in their formation.

Rhenium and manganese carbonyl compounds incorporating tridentate chelating pyrazolyl gallate ligands

1985 ◽  
Vol 63 (8) ◽  
pp. 2261-2272 ◽  
Author(s):  
Brenda M. Louie ◽  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter
Keyword(s):  
Carbonyl Compounds ◽  
Reducing Agents ◽  
X Ray ◽  
H Nmr ◽  
Structure Determinations ◽  
Manganese Carbonyl ◽  
Rhenium Tricarbonyl ◽  
Mode Of Coordination ◽  
Selection Of

The coordinating properties of a variety of unsymmetrical uninegative tridentate chelating "pyrazolylgallate" ligands have been studied using the tricarbonyl moieties "M(CO)3", where M = Mn or Re, as acceptor species. A series of monomeric, pseudo octahedral complexes has been characterized and a fac mode of coordination established for the tridentate gallate ligands from 1H nmr, ir measurements, and X-ray structure determinations. Nitrosylation of a selection of the rhenium tricarbonyl compounds has yielded a number of cationic rhenium mononitrosyl dicarbonyl species. The reactivity of these cations towards reducing agents has been investigated.

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.

Mixed Transition Metal/Lanthanide Complexes: Structural Characterization of Solids Containing Cage Amine Chromium(III) Cations and Tris(dipicolinato)lanthanide Anions

1995 ◽  
Vol 48 (4) ◽  
pp. 807 ◽  
Author(s):  
JM Harrowfield ◽  
Y Kim ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Transition Metal ◽  
Crystal Lattice ◽  
Structural Characterization ◽  
Lanthanide Complexes ◽  
Room Temperature ◽  
X Ray ◽  
Structure Determinations ◽  
Full Structure ◽  
Mixed Transition

As the foundation to a survey of interactions between chromium(III) and lanthanide(III) ions within the same crystal lattice, a series of complexes of stoichiometry [Cr((NH2)2sar)]- [ Ln ( dipic )3].8H2O (sar = 3,6,10,13,16,19-hexaazabicyclo[6.6.6] icosane, Ln = La-Lu plus Y, dipic = pyridine-2,6-dicarboxylate) has been synthesized and structurally characterized by room-temperature single-crystal X-ray studies. An isomorphous series is found for all Ln, being triclinic, Pī , a ≈ 18.1, b ≈ 13.3, c ≈ 11 Ǻ, α ≈ 111.5, β ≈ 96.2, γ ≈ 109.2°, Z = 2 formula units, full structure determinations being recorded for Ln = La (conventional R 0.048 on |F| for No 6494 independent 'observed' [I > 3σ(I)] reflections at convergence), Ce (R 0.036 for No 8980) and Lu (R 0.046 for No 6791). A less well defined protonated series, with a 2:3 Cr/ Ln ratio, has also been characterized specifically for Ln = La [orthorhombic, Pbca , a 26.223(8), b 53.17(3), c 18.329(9) Ǻ, Z = 8; R 0.092 for No 5104], the lutetium analogue having a similar cell.

Synthetic and Structural Studies in the Lanthanide Toluene-4-sulfonate Hydrates

1992 ◽  
Vol 45 (3) ◽  
pp. 583 ◽  
Author(s):  
DL Faithfull ◽  
JM Harrowfield ◽  
MI Ogden ◽  
BW Skelton ◽  
K Third ◽  
...  
Keyword(s):  
Water Molecules ◽  
Space Group ◽  
X Ray ◽  
Lattice Water ◽  
Lanthanide Elements ◽  
Counter Ions ◽  
Dehydration Reactions ◽  
Structure Determinations ◽  
Contemporary Work ◽  
Trigonal Prismatic

Single-crystal X-ray structure determinations at c. 295 K are reported for representative members of the hydrated toluene-4-sulfonates of the lanthanide elements. The early members of the series, represented by lanthanum, cerium and neodymium, are monoclinic tridecahydrates , space group C2/c, a ≈ 32, b ≈ 7.2, c ≈ 35 �, β ≈ 115 �, Z = 8; the cation is a tricapped trigonal prismatic nonaaqualanthanide (III) species, with three toluene-4-sulfonate counter ions and four lattice water molecules per formula/asymmetric unit. The later members of the series, represented by samarium, lutetium and also yttrium, are, in agreement with contemporary work, monoclinic nonahydrates , space group P21/n, a ≈ 25, b ≈ 7.5, c ≈ 17.8 � , β ≈ 99�, Z = 4; the cation is a square prismatic hexaaquabis (toluene-4-sulfonato)lanthanide(III) species with a single toluene-4-sulfonate counter ion and three lattice water molecules. The solid state dehydration reactions of the tridecahydrates are complicated but there is at least one more endothermic step than is observed for the nonahydrates , with both series of compounds appearing to undergo water loss only below 300�C.

Neue Pentaphosphaferrocene

2009 ◽  
Vol 64 (1) ◽  
pp. 3-10 ◽  
Author(s):  
Fabian Dielmann ◽  
Roger Merkle ◽  
Sebastian Heinl ◽  
Manfred Scheer
Keyword(s):  
Crystal Lattice ◽  
Stacking Interactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cyclopentadienyl Ligand ◽  
Π Stacking ◽  
Diffraction Structure ◽  
Structure Determinations ◽  
Phenyl Rings ◽  
Derivatives Of

By cothermolysis of [CpRFe(CO)2]2 [CpR = η5-C5(CH2Ph)5 (Cpbn) (1) and η5-C5Me4C2H4SMe (CpS) (2)] with P4 phosphorus two novel pentaphosphaferrocenes of the formula [CpRFe(η5-P5)] [CpR = CpS (3), Cpbn (4)] have been synthesised and comprehensively characterised. These two products represent the first derivatives of this class of compounds with a functionalised as well as a sterically bulky adjacent cyclopentadienyl ligand. The pentabenzylcyclopentadienyl derivative 4 as well as both of the starting materials [CpRFe(CO)2]2 1 and 2 have been additionally characterised by X-ray diffraction structure determinations. The pentaphosphaferrocene 4 represents in the crystal lattice highly aggregated units via intra- and intermolecular π-stacking interactions of the phenyl rings of the Cpbn ligand.

New insights about the host–guest chemistry of the tungsten oxo complex of calix[4]arene, and novel "one pot" difunctionalizations of calix[4]arene using tetrachlorometal(VI) oxide (M = Mo, W)

2004 ◽  
Vol 82 (10) ◽  
pp. 1452-1461 ◽  
Author(s):  
Pascal Mongrain ◽  
Jasmin Douville ◽  
Jonathan Gagnon ◽  
Marc Drouin ◽  
Andreas Decken ◽  
...  
Keyword(s):  
Water Molecule ◽  
Lewis Acid ◽  
Chemical Shifts ◽  
Strong Interactions ◽  
Ir Absorption ◽  
One Pot ◽  
X Ray ◽  
Strong Lewis Acid ◽  
Successful Removal ◽  
Coordinated Water

The strong Lewis acid tungsten oxo complex of calix[4]arene can be obtained in both hydrated and non-hydrated forms. This complex coordinates a water molecule inside the cavity via strong O···W interactions with relatively short distances of 2.284(4) and 2.329(2) Å for the tungsten oxo complex of calix[4]arene··H2O·aniline (1), and the tungsten oxo complex of calix[4]arene·H2O·toluene (2·toluene), respectively. The strong interactions are also deduced by the relatively high H2O elimination temperature observed by TGA and DSC (above 200 °C). The coordinated water molecule inside the calix[4]arene cavity is characterized by a strong IR absorption at 3616 cm–1, and a narrow resonance at ~1.2 ppm (the chemical shifts of the uncoordinated water are 1.55 and 1.60 ppm in C6D6 and CDCl3, respectively). This water molecule gives rise to H-bonds with aniline in 1. The tungsten oxo complex of 5,11,17,23-tetrabromocalix[4]arene (4), also binds H2O as the characteristic signatures are observed. The successful removal of H2O in 2, is performed under mild conditions using bis(tetrahydrofuran)-uranyl nitrate as a competitive Lewis acid. When this reaction is performed in acetonitrile, butyronitrile or tert-butylnitrile, the corresponding tungsten oxo complexes of calix[4]arene·acetonitrile (3), ·butyronitrile (5), and ·tert-butylnitrile (6) are obtained. The use of uranyl as a H2O abstractor is unprecedented. The X-ray structure of 3 consists of a tungsten oxo complex of calix[4]arene coordinated by an acetonitrile molecule (d(W···N = 2.412(2) Å). The tetra-5,11,17,23-choromethyl-25,26,27,28-tetrahydroxycalix[4]arene reacts with M(O)Cl4 (M = Mo, W) in a 1:1 stoichiometry, via a tetra Friedel–Crafts addition of benzene or toluene, followed by a lower-rim complexation of the metal oxide, to form "flower-shaped" calix[4]arenes. This "one pot" double functionalization is unprecedented.Key words: calix[4]arene, tungsten, molybdenum, X-ray, host–guest, Friedel–Crafts, Lewis acid, uranyl, DSC, TGA.

Crystal structure and lattice energetics of 10-methylacridinium halides

2000 ◽  
Vol 53 (8) ◽  
pp. 627 ◽  
Author(s):  
Piotr Storoniak ◽  
Karol Krzyminski ◽  
Pawel Dokurno ◽  
Antoni Konitz ◽  
Jerzy Blazejowski
Keyword(s):  
Crystal Lattice ◽  
Lattice Energy ◽  
Enthalpies Of Formation ◽  
Triclinic Space Group ◽  
X Ray ◽  
Molecular Arrangement ◽  
Van Der Waals Contacts ◽  
Chloride Monohydrate ◽  
Insight Into

The crystal structures of 10-methylacridinium chloride monohydrate, bromide monohydrate and iodide were determined by X-ray analysis. The compounds crystallize in the triclinic space group, P¯1, with 2 molecules in the unit cell. The molecular arrangement in the crystals revealed that hydrogen bonds (in hydrates) and van der Waals contacts play a significant part in intermolecular interactions. To discover their nature, contributions to the crystal lattice energy arising from electrostatic (the most important since the compounds form ionic crystals), dispersive and repulsive interactions were calculated. Enthalpies of formation of the salts, their stability and susceptibility to decomposition could be predicted from a combination of crystal lattice energies with values of other thermochemical characteristics obtained theoretically or taken from the literature. The role of water in the stabilization of the crystal lattice of the hydrates is also explained. The information gathered has given an insight into the features and behaviour of compounds which can be regarded as models of a large group of aromatic quaternary nitrogen salts.

Preparations, X-ray crystal structure determinations, and base strength measurements of substituted tritylamines

2000 ◽  
pp. 85-92 ◽  
Author(s):  
Moisés Canle L. ◽  
William Clegg ◽  
Ibrahim Demirtas ◽  
Mark R. J. Elsegood ◽  
Howard Maskill
Keyword(s):  
Crystal Structure ◽  
X Ray ◽  
Structure Determinations ◽  
Base Strength

Structural dynamics of PZT thin films at the nanoscale

2005 ◽  
Vol 902 ◽  
Author(s):  
Alexei Grigoriev ◽  
Dal-Hyun Do ◽  
Dong Min Kim ◽  
Chang-Beom Eom ◽  
Bernhard Adams ◽  
...  
Keyword(s):  
Crystal Lattice ◽  
Lattice Distortion ◽  
Piezoelectric Effect ◽  
Polarization Switching ◽  
X Rays ◽  
Time Resolved ◽  
X Ray ◽  
Converse Piezoelectric Effect ◽  
Ferroelectric Capacitors ◽  
Crystal Lattice Distortion

AbstractWhen an electric field is applied to a ferroelectric the crystal lattice spacing changes as a result of the converse piezoelectric effect. Although the piezoelectric effect and polarization switching have been investigated for decades there has been no direct nanosecond-scale visualization of these phenomena in solid crystalline ferroelectrics. Synchrotron x-rays allow the polarization switching and the crystal lattice distortion to be visualized in space and time on scales of hundreds of nanometers and hundreds of picoseconds using ultrafast x-ray microdiffraction. Here we report the polarization switching visualization and polarization domain wall velocities for Pb(Zr0.45Ti0.55)O3 thin film ferroelectric capacitors studied by time-resolved x-ray microdiffraction.

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