PROTON NMR-SPECTROSCOPY AS A PROBE OF DINUCLEAR COPPER(II) CENTERS

One- and two-dimensional H-1 NMR spectra of the antiferromagnetically coupled (mu-phenoxo)(mu-hydroxo)dicopper(II) complex [Cu-2(BPMP)(OH)](ClO4)(3) (1) were recorded. Complex 1 exhibits a H-1 NMR spectrum with 10 hyperfine shifted signals between +150 and -50 ppm, accounting for all of the protons in the complex. Clear COSY cross-signals are observed between hyperfine shifted signals, allowing the complete assignment of the H-1 NMR spectrum. These data, coupled with X-ray crystallographic results for 1, indicate that a paramagnetic dipolar relaxation mechanism is the dominant proton relaxation pathway.