... were obtained as previously described," by using 514.5-nm excitation, at a power of 500-1200 mW and a reso- lution of 8 cm-l. Proton NMR spectra were obtained in DMSO-d, by using a Varian A-60 spectrometer, with chemical shifts (6/ppm ... 482 Inorganic Chemistry, Vol. 29, No. ...