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Coordination Chemistry of Acrylamide. 6 Synthesis and Coordination Compounds of N ‐Pyrazolylpropanamide – a Versatile Acrylamide‐derived Ligand
Author(s) -
Girma Kibatu B.,
Lorenz Volker,
Blaurock Steffen,
Edelmann Frank T.
Publication year - 2008
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.200700383
Subject(s) - chemistry , ligand (biochemistry) , amide , cobalt , crystal structure , coordination complex , metal , octahedron , crystallography , octahedral molecular geometry , medicinal chemistry , polymer chemistry , inorganic chemistry , organic chemistry , biochemistry , receptor
The syntheses, spectroscopy and single crystal X‐ray structures of the multifunctional acrylamide‐derived ligand N ‐pyrazolylpropanamide (= L) ( 1 ), and its complexes [L 2 CuCl 2 ] ( 2 ) and [L 4 Co 3 Cl 6 ] ( 3 ) with copper(II) and cobalt(II) chlorides, respectively, are described. The ligand 1 is easily obtained in one step by the reaction of pyrazole with acrylamide in a 1:1 molar ratio in the presence of trimethylbenzylammonium hydroxide as a basic catalyst. The reaction of CuCl 2 ·2H 2 O with 1 in a 1:2 metal salt:ligand molar ratio in ethanol/‐triethylorthoformate solution gave coordination compound 2 . The crystal structure of 2 contains two seven‐membered chelate rings formed by two nitrogen atoms of the pyrazolyl groups and two weakly coordinated carbonyl oxygen atoms of the substituted amide moieties. Two chloride ions in the axial positions complete a distorted octahedral coordination environment around the Cu II atom. The reaction of CoCl 2 ·6H 2 O with 1 in a 1:2 metal salt:ligand molar ratio afforded the unusual zwitterionic complex 3 . The crystal structure of 3 contains a central cobalt atom in an octahedral coordination surrounded by four ligands in which two of them act as chelate ligands and the other two, coordinated via the carbonyl oxygen atoms of the amide moieties to this metal center, act as bridging ligands bonded to two CoCl 3 − units.