Structural and spectroscopic characterisation of tris(2-benzimidazolylmethyl)amine coordination compounds of Zn(II), Cd(II) and Hg(II)
Por:
Quiroz-Castro E., Bernès S., Barba-Behrens N., Tapia-Benavides R., Contreras R., Nöth H.
Publicada:
1 ene 2000
Resumen:
Zinc(II), cadmium(II) and mercury(II) coordination compounds derived from tris(2-benzimidazolylmethyl)amine (ntb) were characterised by 1H and 13C NMR in solution, IR and X-ray single crystal diffraction for [Zn(ntb)Cl]2[ZnCl4]·4EtOH, [Cd(ntb)(?2-NO3)]NO3·2DMSO and [Hg(ntb)Cl]2[HgCl4]·4EtOH. The complexes derived from zinc(II), cadmium(II) and mercury(II) halides form [M(ntb)X]+ cations, where the metal ions are pentacoordinated and have a distorted trigonal bipyramidal geometry, with tetrahedral anions [MX4]2-. In the [Cd(ntb)(?2-NO3)]NO3·2DMSO complex, by analogy with the Zn(II) and Hg(II) compounds, the NO3 - could be considered as the fifth apical substituent in a distorted trigonal bipyramid geometry. In all complexes the ligand is coordinated to the metal through the imidazolic nitrogen atoms and has a weak coordination with the tertiary amine. The counter ion (halide or nitrate) remains bonded to the metal ion in solution and in the solid state as was evidenced by NMR and X-ray diffraction. The structures presented interactions between the coordinated counterion and the nearest C-H of the aromatic rings. All cations show an approximate C3 symmetry. The distortions found in the solid state were attributed to intermolecular hydrogen bonding and stacking between the benzimidazolic rings of neighbouring molecules. (C) 2000 Elsevier Science Ltd.
Filiaciones:
Quiroz-Castro E.:
Facultad De Química, Universidad Nacional Autónoma De México, CU 04510, Mexico DF, Mexico
Bernès S.:
Facultad De Química, Universidad Nacional Autónoma De México, CU 04510, Mexico DF, Mexico
Barba-Behrens N.:
Facultad De Química, Universidad Nacional Autónoma De México, CU 04510, Mexico DF, Mexico
Tapia-Benavides R.:
Centro De Investigaciones Químicas, Universidad A. del Estado De Hidalgo, Carretera Pachuca-Tulancingo, Km. 45. U. Universitaria, Pachuca Hidalgo CP 42074, Mexico
Contreras R.:
Departamento De Química, Centro De Investigación Y Estudios Avanzados del IPN, Apdo. Postal 14-740, 07000 Mexico DF, Mexico
Nöth H.:
Institute of Inorganic Chemistry, University of Munich, Butenandtstraße 5-13 (Haus D), D-81377 Munich, Germany
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