Structural Studies of Alkaline Earth Metal Picrates

1995 ◽  
Vol 48 (7) ◽  
pp. 1333 ◽  
Author(s):  
JM Harrowfield ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Nitro Group ◽  
Alkaline Earth ◽  
Earth Metal ◽  
Linear Polymer ◽  
Alkaline Earth Metal ◽  
Water Molecules ◽  
X Ray ◽  
Main Group Metal ◽  
Group Oxygen ◽  
Structure Determinations

Room-temperature, single-crystal X-ray structure determinations are recorded for alkaline earth metal picrates , M( pic )2.nH2O(M = Mg, Sr , Ba ; Hpic = 2,4,6-trinitrophenol, HOC6H2(NO2)3), all crystallized from aqueous solution. Magnesium picrate ,shown to be the nonahydrate, Mg( pic )2.9H2O, forms monoclinic crystals, space group P21/c, a 15.023(3), b 6.718(4), c 26.516(2) Ǻ, β 109.55(1)°, Z = 4 f.u .,conventional R on |F| was 0.049 for No = 4062 'observed' (I > 3σ(I)) reflections. The structure, unusually among the main group metal picrates studied so far, has no coordinative interaction between the metal and the picrate anion; the complex may be formulated as [Mg(OH2)6] ( pic )2.3H2O, with the metal present as the hexaaqua species (Mg-O 2.043(2)-2.077(2)Ǻ). The picrate ions are stacked end to end, presumably as a result of charge-transfer interactions, parallel to b, with side-by-side stacks forming a sheet along ab, and successive sheets are interleaved by layers of cations and water molecules. The strontium salt is a pentahydrate , monoclinic, C2/c, a 24.515(6), b 10.142(6), c 17.932(4) Ǻ, β 98.76(2)°, Z = 8 f.u .; R was 0.046 for No 2731. The complex is a linear polymer, [(H2O)3Sr(O,O′- pic )2(μ-OH2)](∞|∞).H2O, with eight-coordinate (SrO8) strontium. The barium salt is a hexahydrate , also a linear polymer [(H2O)5Ba(O,O′-pic )( O,O′,μ-O″-pic )]∞|∞).H2O, the ten-coordinate (BaO10) barium environment comprising the five water molecules, a pair of picrates, bidentate /chelating via the phenolic oxygen and a 2-nitro group oxygen, with one of the picrates from an adjacent metal atom offering an additional 4-nitro group oxygen, this bridging successive barium atoms. The complex is triclinic, Pī , a 15.120(5), b 11.633(3), c 6.766(3) Ǻ, α 87.24(3), β 79.16(3), γ 84.88(2)°, Z = 2 f.u .; R was 0.027 for No 3904. Repeated attempts to obtain crystals of beryllium picrate suitable for an X-ray structure determination were unsuccessful.

Über Erdalkalimetalloxogallate, VI Zum Problem der Mischkristallbildung zwischen CaGa2O4 und CaAl2O4 / On Alkaline Earth Metal Oxogallates, VI About Mixed Crystal Formation of CaGa2O4-CaAl2O4

1976 ◽  
Vol 31 (12) ◽  
pp. 1604-1606 ◽  
Author(s):  
Hk. Müller-Buschbaum ◽  
W. Schmachtel
Keyword(s):  
Single Crystal ◽  
Alkaline Earth ◽  
Mixed Crystal ◽  
Earth Metal ◽  
Mixed Crystals ◽  
Alkaline Earth Metal ◽  
Crystal Formation ◽  
X Ray ◽  
Mixed Crystal Formation

Mixed crystals of the formulae CaGaAlO4 (1) and CaGa0.5Al1.5O4 (2) were investigated by X-ray single crystal work. 1 shows a tetrahedral orientation like that of CaGa2O4 (monokl.), 2 another one of CaAl2O4. A discussion of the different polyhedral arrangement of the stuffed tridymite structures is given.

Polypyridines, Picrates, Lanthanides: A Plethora of Stacks?

2020 ◽  
Vol 73 (6) ◽  
pp. 529
Author(s):  
Eric J. Chan ◽  
Simon A. Cotton ◽  
Jack M. Harrowfield ◽  
Brian W. Skelton ◽  
Alexandre N. Sobolev ◽  
...  
Keyword(s):  
Nitro Group ◽  
The Other ◽  
Molar Ratio ◽  
Lanthanide Ion ◽  
X Ray ◽  
The Third ◽  
Group Oxygen ◽  
Structure Determinations ◽  
Lighter Lanthanides ◽  
Trigonal Prismatic

Reactions of the lanthanide(iii) picrates (picrate=2,4,6-trinitrophenoxide=pic) with 1,10-phenanthroline (phen) and 2,2′:6′,2′′-terpyridine (terpy) in a 1:2 molar ratio have provided crystals suitable for X-ray structure determinations in instances predominantly involving the lighter lanthanides. In all, the aza-aromatic ligands chelate the lanthanide ion, none being found as ‘free’ ligands within the lattice. The complexes of 1,10-phenanthroline have been characterised in two forms, one unsolvated (Ln=La, Sm, Eu; monoclinic, C2/c, Z 8), one an acetonitrile monosolvate (Ln=Gd; monoclinic, P21/a, Z 4), the latter being the only previously known form (with Ln=La). In both forms, the LnIII is nine-coordinate, in an approximately tricapped trigonal-prismatic environment, with two picrate ligands chelating through phenoxide and 2-nitro group oxygen atoms, the third being bound through phenoxide-O only. The 2,2′:6′,2′′-terpyridine complexes, all acetonitrile monosolvates defined for Ln=La, Gd, Er, and Y (monoclinic, C2/c, Z 4), are ionic, one picrate having been displaced from the primary coordination sphere. For Ln=La, the two bound picrates are again chelating, making the LaIII 10-coordinate in a distorted bicapped square-antiprismatic environment but in the other species they are bound through phenoxide-O only, making the LnIII ions eight-coordinate in a distorted square-antiprismatic environment. Stacked arrays of the ligands can be found in both series of complexes, with intramolecular picrate–picrate and picrate–aza-aromatic stacks being prominent features.

Alkaline earth metal-based metal–organic framework: hydrothermal synthesis, X-ray structure and heterogeneously catalyzed Claisen–Schmidt reaction

2014 ◽  
Vol 43 (34) ◽  
pp. 13006-13017 ◽  
Author(s):  
Debraj Saha ◽  
Tanmoy Maity ◽  
Subratanath Koner
Keyword(s):  
Hydrothermal Synthesis ◽  
Alkaline Earth ◽  
Metal Organic Framework ◽  
Earth Metal ◽  
Alkaline Earth Metal ◽  
Schmidt Reaction ◽  
X Ray ◽  
Chelidamic Acid ◽  
Metal Organic ◽  
Organic Framework

Two alkaline earth metal based carboxylate framework systems, [Mg(HL)(H2O)2]n (1) and [Ca(H2L)2]n (2) (H3L = chelidamic acid) have been hydrothermally synthesized and characterized. Both compound 1 and its dehydrated species heterogeneously catalyze Claisen–Schmidt reaction.

X-ray photoelectron spectroscopy of alkaline earth metal uranate complexes

1978 ◽  
Vol 3 (1) ◽  
pp. 229-233 ◽  
Author(s):  
Geoffrey C. Allen ◽  
Andrew J. Griffiths ◽  
Barrington J. Lee
Keyword(s):  
Photoelectron Spectroscopy ◽  
Alkaline Earth ◽  
Earth Metal ◽  
Alkaline Earth Metal ◽  
X Ray

Lanthanum tetrazinc, LaZn4

2012 ◽  
Vol 68 (6) ◽  
pp. i37-i40 ◽  
Author(s):  
Igor Oshchapovsky ◽  
Volodymyr Pavlyuk ◽  
Grygoriy Dmytriv ◽  
Alexandra Griffin
Keyword(s):  
Rare Earth ◽  
Diffraction Data ◽  
Alkaline Earth ◽  
Earth Metal ◽  
Structure Type ◽  
Alkaline Earth Metal ◽  
X Ray Diffraction ◽  
X Ray ◽  
A Site ◽  
First Time

The structure of lanthanum tetrazinc, LaZn4, has been determined from single-crystal X-ray diffraction data for the first time, approximately 70 years after its discovery. The compound exhibits a new structure type in the space groupCmcm, with one La atom and two Zn atoms occupying sites withm2msymmetry, and one Zn atom occupying a site with 2.. symmetry. The structure is closely related to the BaAl4, La3Al11, BaNi2Si2and CaCu5structure types, which can be presented as close-packed arrangements of 18-vertex clusters, in this case LaZn18. The kindred structure types contain related 18-vertex clusters around atoms of the rare earth or alkaline earth metal.

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