Protonated N , N ′-Dioxide-4,4′-bipyridine, an Interesting Synthon for the Building of Polar H-Bonded Networks?
2011; American Chemical Society; Volume: 11; Issue: 12 Linguagem: Inglês
10.1021/cg201299n
ISSN1528-7505
AutoresNicolas Leblanc, Magali Allain, Nicolas Mercier, Elena Cariati,
Tópico(s)Inorganic Fluorides and Related Compounds
ResumoA slow liquid–gas diffusion method in strong acid conditions has allowed stabilizing for the first time in the solid state the diprotonated form of the 4,4′-bipyridine-N,N′-dioxide (bp4do), H2bp4do2+ as two polymophs of the chloride salt (H2bp4do)Cl2, while in the presence of a metallic salt M(III)Br3 (M = Bi, Sb), the monoprotonated form Hbp4do+ is mainly stabilized as (Hbp4do)2[Sb2Br8] and (H2bp4do)(Hbp4do)4[Bi4Br18]·2H2O. The dehydration of this last phase leads to (H2bp4do)(Hbp4do)4[Bi4Br18]. In the structures of (H2bp4do)Cl2 salts, the hydroxyl H atoms point toward the chloride anions leading to close (O)H···Cl contacts in the range 1.831–1.839 Å. A one-dimensional network of H-bonded Hbp4do+ cations is found in the structure of (Hbp4do)2[Sb2Br8], whereas H-bonded supramolecular cations of five entities are found in the structures of bromobismuthate salts. In all the halometallate structures, X-ray analyses (293 K and 120 K data) did not allow us to locate the acid H atoms of protonated bp4do molecules certainly due to a disorder phenomenon but also revealing an asymmetrical H-bonding situation. The bromobismuthate hybrids are nonlinear optical active with a powder second harmonic generation efficiency being half that of urea.
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