SYNTHESIS OF METALLOMACROCYCLOPHANES - DEDUCTION OF STRUCTURE FROM ELECTROSPRAY-IONIZATION MASS-SPECTROSCOPY AND MOLECULAR MECHANICS COMPUTATIONS

The synthesis of metallomacrocyclophanes 7-tos and 8, in which environ mentally tunable ferric-catecholamide coordination bonds hold the cycl ophane together, is described. W-vis spectroscopic studies of 7-tos an d 8 display characteristics of ferric-tris(catecholamide) complexes, i .e. burgundy color (lambda(max) = ca. 490 nm)and high stability, at hi gh pH, and 1:1 stoichiometry. Electrospray ionization mass spectra of 8 show prominent ions due to a monomeric 1:1 (ligand/metal) complex. M olecular mechanics calculations on 7 and 8 indicate that oar-isomeric configurations predominate, leaving a void in the metallomacrocyclopha ne interiors.