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Halido‐Bridged Dinuclear Nickel and Zinc Complexes with a Bis(tripodal) Octaamine Ligand – Unusual Coordination Mode of an ortho ‐Phenylenediamine
Author(s) -
Hahn F. Ekkehardt,
Schröder Henning,
Pape Tania
Publication year - 2009
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.200900656
Subject(s) - chemistry , zinc , ligand (biochemistry) , tetrafluoroborate , nickel , tripodal ligand , metal , halide , crystallography , amine gas treating , stereochemistry , medicinal chemistry , polymer chemistry , crystal structure , inorganic chemistry , ionic liquid , organic chemistry , catalysis , biochemistry , receptor
A potentially dinucleating octaamine ligand H 6 ‐ 4 consisting of two aliphatic tripodal tetraamine units connected by an ortho ‐phenylenediamine spacer has been synthesized. Treatment of H 6 ‐ 4 with Ni(BF 4 ) 2 · 6H 2 O or H 10 ‐ 4 (BF 4 ) 4 with Et 2 Zn in the presence of a halide source leads to the formation of the dinuclear complexes [Ni 2 (μ‐Cl) 2 (H 6 ‐ 4 )](BF 4 ) 2 ( 5 ) and [Zn(μ‐F)(H 6 ‐ 4 )](BF 4 ) 3 ( 6 ), respectively, which were structurally characterized by X‐ray diffraction studies. In both 5 and 6 the ligand coordinates with four nitrogen donors to each metal center. The ortho ‐phenylenediamine bridging unit coordinates in an unprecedented fashion with each of its amine functions to only one of the metal centers. The dinickel complex 5 possesses two bridging chlorido ligands that differ notably in their Cl–Ni bond lengths, due to interactions of four amine N–H protons with one of the chlorido bridges leading to a reduced donor ability. The dizinc complex 6 was synthesized without addition of an external halide source. The two zinc atoms in 6 facilitate the abstraction of a fluoride from a tetrafluoroborate anion through a cooperative activation by the two adjacent metal centers. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)