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Crystal and Molecular Structure of the 4:3 Complex between Lanthanum Nitrate and Pentaethyleneglycol Dimethyl Ether
Author(s) -
Bünzil JeanClaude C.,
Pfefferlé JeanMarc,
Ammann Bruno,
Chapuis Gervais,
Zuniga F.Javier
Publication year - 1984
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19840670426
Subject(s) - chemistry , monoclinic crystal system , crystallography , crystal structure , moiety , molecule , lanthanum , x ray crystallography , ion , ether , stereochemistry , bond length , diffraction , inorganic chemistry , physics , organic chemistry , optics
The crystal and molecular structure of [La(NO 3 ) 3 ] 4 (C 12 H 26 O 5 ) 3 has been determined from low‐temperature single‐crystal X‐ray diffraction data. The complex crystallizes in the monoclinic space group I 2 with Z = 2. Lattice parameters at 150 K are a = 12.234 (6) Å, b = 11.105 (5), c = 26.613 (9), β = 90.65 (4)°. The structure was solved by Patterson and Fourier techniques and refined to a conventional R F ‐value of 0.068. The compound contains three dinitrato complex cations [La(NO 3 ) 2 C 12 H 26 O 6 ] + with 10‐coordinate lanthanum ions and one hexanitrato anion, [La(NO 3 ) 6 ] 3− , with a 12‐coordinate La(III)‐ion. One complex cation has a C 2 ‐symmetry while the two others, which are crystallographically equivalent, have no symmetry and contain a disordered ligand molecule. The polyther adopts a ring‐like conformation in all the complex moietis. The LaO(nitrate) distances lie in the ranges 2.52–2.53 and 2.49–2.62 Å, with average values of 2.53 (7) and 2.56 (6) Å, respectively, fo the species with C 2 ‐ and C 1 ‐symmetry; the LaO(ether) bond lengths lie int he range 2.54–2.79 Å (average: 2.6 (1)) for the C 2 ‐moiety and their mean value amounts to 2.6 (2) for the disordered species. The hexanitrate has a C 2 ‐symmetry and the LaO distances range between 2.56 and 2.67 Å with an average value fo 2.64 (4) Å. The effective ionic radii of the 10‐ and 12‐coordinate La(III) ions are estimated as 1.28 and 1.33 Å, respectively.