75506-17-1Relevant academic research and scientific papers
RHODIUM CARBONYL CLUSTER CHEMISTRY UNDER HIGH PRESSURE OF CARBON MONOXIDE AND HYDROGEN. VII. CONVERSION OF 3- INTO OTHER HIGH NUCLEARITY CLUSTERS: NEW HIGH-YIELD SYNTHESES FOR 3- AND 2-
Vidal, Jose L.,Schoening, R.C.
, p. 217 - 227 (1981)
The interconversions of 3-, 3-, and 4- have been studied under high pressure of an equimolar mixture of carbon monoxide and hydrogen (12-15 atm; 140-160 deg C).The three clusters can be selectively prepared from identical reaction mixtures (Rh(CO)2acac, CsPhCO2, in glyme solvent) using different contact times.A new synthesis for 3- by exposing this solution for less than 0.5 hours to reaction conditions was discovered in this way.This procedure allows the preparation of 5-20 g of the cluster, isolated as the bis(triphenylphosphine) iminium salt with a 95percent yield in a 8-hour working period.The fragmentation of 3- to Rh2(CO)8 and the aggregation of this dimer with the initial cluster is suggested to form 3-.Conversion of 3- into 4- or 2- occurs subsequently by reaction with carbon monoxide and hydrogen, or by treatment with trifluoromethane sulfonic acid; 3- has also been converted into 3- by reaction with formaldehyde in the presence of hydrogen (67 atm, 125 deg C).The oxidative aggregation of two large clusters to yield an even larger species is promoted by protonic acids: 3- and CF3SO3H react to give 2-.The effects of the cations on the redox aggregation-fragmentation reactions of the clusters have been noted for the first time during these studies.
