THE CATALYSIS OF IRON-COBALT BIMETALLIC CLUSTERS——1.THERMAL STABILITY AND DECOMPOSITION REACTION OF[R_4N][FeCo_3(CO)_(12)]IN SOLUTION

Thermal decomposition of[R4N][FeCo3（CO）12][I]（R=ethyl,butyl,hexadecyl,benzyltrimethyl,benzyltriethyl）in n-heptane,toluene and methanol was investigated bythe in situ high pressure IR spectroscopic method.The results show that underhydroformylation conditions all clusters decompose to Co2（CO）8,Fe（CO）5 and the salt ofCo（CO）4-,and Co2（CO）8 reacts with H2 to form HCo（CO）4.Thermal stability of theclusters decrease with the increase of polarity of solvents.Under the hydroformylation con-ditions,IR spectra of the clusters are compatible with those of Fe（CO）5+Co2（CO）8+[R4N]Cl system.Because of the stabilizing effect or tetra-alkylammonium cation,when the tem-perature drops below 50℃ after decomposition of the clusters,the characteristic absorptionbands of the clusters appear again,so the decomposition process is reversible.

Thermal decomposition of [R4N] [FeCo3(CO) 12] [I] (R=ethyl, butyl, hexadccyl, benzyltrimethyl, benzyltriethyl) in n-heptane, toluene and methanol was investigated by the in situ high pressure IR spectroscopic method. The results show that under hydroformylation conditions all clusters decompose to Co2(CO)8, Fe(CO)5 and the salt of Co (CO)4-, and Co2(CO)8 reacts with H2 to form HCo(CO)4. Thermal stability of the clusters decrease with the increase of polarity of solvents. Under the hydroformylation conditions, IR spectra of the clusters are compatible with those of Fe (CO)5+Co2 (CO) 8+ [R4N] Cl system. Because of the stabilizing effect of tctra-alkylammonium cation, when the temperature drops below 50℃ after decomposition of the clusters, the characteristic absorption bands of the clusters appear again, so the decomposition process is reversible.