Iron, carbonyl compounds triiron dodecacarbonyl

The first experiments which were carried out in the author s laboratory on organometallic phase-transfer catalysis were concerned with the reduction of nitrobenzenes (4) to anilines (5) by triiron dodecacarbonyl. Such a conversion was reported to occur in benzene containing methanol at reflux for 10-17 h, with the hydridoundecacarbonyltriferrate anion as the likely key intermediate (16). It was our expectation that the trinuclear iron hydride should be generated by phase-transfer catalysis and if so, effect reduction of nitro compounds (4) under exceedingly mild conditions. Indeed this was the case, as illustrated by the results shown in Table I (17). Not only is the reaction complete in 2 h or less using sodium hydroxide as the aqueous phase, benzene as the organic phase, and benzyltrieth-ylammonium chloride as the phase-transfer catalyst, but it occurs at room temperature and requires less metal carbonyl than when the reaction was... 

Another inorganic particle that has been prepared via RESS is iron oxide (Fe203) (75). The preparation involved rapid expansion of a Fe(N03)3 solution in supercritical water. The expansion was at 500°C and 100 MPa through 50-to 200-p,m-diameter orifices into an evacuated chamber. The Fe203 particles thus obtained were small and exhibited exceptional reactivities. In addition to inorganic oxides, several neutral metal carbonyls (chromium hexacarbonyl, dimanganese decacarbonyl, and triiron dodecacarbonyl) were processed via RESS to form micrometer-sized particles (76). The solubility of these compounds allowed the use of supercritical CO2 in the RESS processing. 

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