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Copper Complexes with Neutral N4 Tripodal Ligands: Influence of the Number of Nitrogen Donors on Their Structures, Properties, and Reactivity
Author(s) -
Fujisawa Kiyoshi,
Chiba Shingo,
Miyashita Yoshitaro,
Okamoto Kenichi
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.200900395
Subject(s) - chemistry , copper , denticity , amine gas treating , ligand (biochemistry) , reactivity (psychology) , tripodal ligand , coordination sphere , tris , inorganic chemistry , infrared spectroscopy , crystallography , crystal structure , organic chemistry , receptor , alternative medicine , pathology , medicine , biochemistry
Copper coordination complexes of the neutral tetradentate nitrogen‐containing ligands tris(3,5‐dimethylpyrazol‐1‐ylmethyl)amine (L0N4) and tris(3,5‐diisopropylpyrazol‐1‐ylmethyl)amine (L1N4), namely the copper(II) chlorido complexes [Cu II (L0N4)Cl 2 ] ( 1 ) and [Cu II (L1N4)Cl 2 ] ( 2 ), the copper(II) nitrato complexes [Cu II (L0N4)(NO 3 )](NO 3 ) ( 3 ) and [Cu II (L1N4)(NO 3 )](NO 3 ) ( 4 ), and the copper(II) sulfato complexes [Cu II (L0N4)(SO 4 )] ( 5 ) and [Cu II (L1N4)(SO 4 )] ( 6 ), and the copper(I) complexes [Cu I (L0N4)](PF 6 ) ( 7 ) and [Cu I (L0N4)(PPh 3 )](ClO 4 ) ( 8 ), have been systematically synthesized in order to investigate the influence of the number of nitrogen donors on their structures, properties, and reactivity. All copper(II) complexes were fully characterized by X‐ray crystallography and by IR/far‐IR, UV/Vis absorption, and ESR spectroscopy. Although the structure of 7 was not determined by X‐ray crystallography, this complex and the structurally characterized copper(I) triphenylphosphane complex 8 were fully characterized by IR/far‐IR and NMR spectroscopy. A comparison of the copper(II) complexes with two tris(pyrazol‐1‐ylmethyl)amine ligands with different bulkiness of the pyrazolyl rings has allowed us to evaluate the second coordination sphere effects of the ligands. Moreover, the structures and physicochemical properties of these complexes are compared with those of related complexes containing the neutral tridentate tris(pyrazolyl)methane ligand and the neutral bidentate bis(pyrazolyl)methane ligand. Finally, the relative stability of the copper(I) complexes is discussed. The influence of the number of nitrogen donors in copper complexes is observed from these systematic results.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)