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The Effect of the Steric Bulk of the Ligand on the Geometry of the Species Self‐Assembled from Co III Bis(dioximates) and Boronic Acids
Author(s) -
Dreos Renata,
Nardin Giorgio,
Randaccio Lucio,
Siega Patrizia,
Scagliola Silvia,
Tauzher Giovanni
Publication year - 2004
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.200400314
Subject(s) - chemistry , steric effects , cobalt , moiety , supramolecular chemistry , boronic acid , crystallography , ligand (biochemistry) , stereochemistry , coordination geometry , nmr spectra database , crystal structure , spectral line , molecule , inorganic chemistry , organic chemistry , hydrogen bond , biochemistry , receptor , physics , astronomy
The synthesis and characterization of the products of the reactions between the bis(diphenylglyoximato)cobalt( III ) complexes [Co(CH 3 )(dpgH) 2 L] [L = py or H 2 O; dpgH 2 = bis(diphenylglyoxime)] and 4‐pyridinylboronic acid ( 1 ) and 3‐aminophenylboronic acid ( 2 ) are described. The crystals of both 1 and 2 are built up by dimeric units arranged on a crystallographic symmetry center, so that the 4‐pyridinyl (in 1 ) or the 3‐aminophenyl residue (in 2 ) of one moiety coordinates to the Co atom of the symmetry‐related unit. 1 H NMR spectra show that both 1 and 2 are stable in solution in aprotic solvents: they do not dissociate and are not in equilibrium with species having different nuclearity. The geometry of 1 is very similar to that of the species assembled from the corresponding bis(dimethylglyoximato)cobalt( III ) complex and 4‐pyridinylboronic acid. On the contrary, the replacement of the methyls by phenyls prevents the trimeric arrangement previously found in the supramolecular species assembled from methylcobaloxime and 3‐aminophenylboronic acid and leads to the dimeric species 2 . (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)