Role of the tosyl group on the coordination ability of N-protected aminoacids. 3. Ternary complexes of copper(II) with N-tosylglycine and aromatic amines. Crystal and molecular structure of bis(N-tosylglycinato) bis(N-methylimidazole)copper(II).

Some compounds of the type Cu(TsglyH)2X2 (TsglyH = N-tosylglycinate anion; X = imidazole, N-methylimidazole, andpyridine) have been prepared and characterized by means of magnetic moments and ESR, electronic, and infrared spectra.For one of them, bis(N-tosylglycinato)bis(N-methylimidazole)copper(II), the crystal structure has also been determined. The complex has square-planar coordination via two centrosymmetriccarboxylic oxygens and two imidazole nitrogens. Two weak interactions (2.758 A) with two carboxylic oxygens completethe coordination to a strongly distorted tetragonal bipyramid. Packing is determined by N-H(amide)-.O(carboxylate)hydrogen bonds and by van der Waals contacts. Electronic, infrared, and ESR spectra are consistent with this type ofstructure for all the complexes