MUTUAL EXCHANGE AND ISOMERIZATION PROCESSES IN THE THREE ISOMERS OF THE MIXED-METAL TRIANGULAR CLUSTER COMPLEX RE2PT(MU -H)2(CO)8(PPH3)2

The dynamic processes operative in the three isomers of the triangular cluster [Re 2 Pt(μ-H) 2 (C0) 8 (PPh 3 ) 2 ] have been studied. 1 H and 31 P variable-temperature NMR spectra of the isomer (in which both the phosphines are bound to Pt) indicate the presence of two mutual exchange processes: one, operative at lower temperature, exchanges only the phosphines, while the second one, active above 238 K, exchanges the hybrides