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Inicio » Actividades I+D > Publicaciones 2012 > Bis(2-amino-1H-benzimidazol-3-ium) tetra...
artículo con referato
"Bis(2-amino-1H-benzimidazol-3-ium) tetrakis(μ-but-2-enoato)-κ4O:O′;κ3O,O′:O;κ3O:O,O′-bis[bis(but-2-enoato-κ2O,O′)holmium(III)]"
A.M. Atria, M.T. Garland and R. Baggio
Acta Cryst. C 68(7) (2012) m185-m188
The title ionic compound, (C7H8N3)2[Ho2(C4H5O2)8], is constructed from two almost identical independent centrosymmetric anionic dimers balanced by two independent 2-amino-1H-benzimidazol-3-ium (Habim+) cations. The asymmetric part of each dimer is made up of one HoIII cation and four crotonate (crot or but-2-enoate) anions, two of them acting in a simple η2-chelating mode and the remaining two acting in two different μ2:η2 fashions, viz. purely bridging and bridging-chelating. Symmetry-related HoIII cations are linked by two Ho-O-Ho and two Ho-O-C-O-Ho bridges which lead to rather short intracationic HoHo distances [3.8418 (3) and 3.8246 (3) Å]. In addition to the obvious Coulombic interactions linking the cations and anions, the isolated [Ho2(crot)8]2- and Habim+ ions are linked by a number of N-HO hydrogen bonds, in which all N-H groups of the cation are involved as donors and all (simple chelating) crot O atoms are involved as acceptors. These interactions result in compact two-dimensional structures parallel to (110), which are linked to each other by weaker ππ contacts between Habim+ benzene groups.
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