Metal complexes of phytohormones. part iii. A dimeric copper(ii) complex of 2,4a,7-trihydroxy-1 methyl-8-methylengibb-3-ene-l,10dicarboxylic acid 1→4a-lactone

A compound of the type Cu(GA3COO)2.4H2O(GA3COOH) = 2,4Fla,7-trihydroxy-1 methyl-8-methylengibb-3-ene-l,10 carboxylic acid 1→4 lactone (gibberellic acid) was obtained and characterized by means of magnetic and thermogravimetric measurements, i.r., electronic and e.s.r. spectra at room and low temperature. The spectroscopic measurements are consistent with the fact the ligand appears to behave as a simple carboxylic acid, being able to coordinate to the copper(II) ion in a syn-syn configuration giving a “cupric-acetate”-like dimeric species. © 1990, Taylor & Francis Group, LLC. All rights reserved.