철도데카카보닐

Tri-iron dodecacarbonyl forms deep green, diamagnetic crystals which decompose at 140°C, but which can be sublimed slowly in vacuo. It dissolves in organic solvents and in pentacarbonyl iron in which its molecular weight corresponds to Fe3(CO)12.

Tri-iron Dodecacarbonyl was first obtained by thermal decomposition of non aqueous solutions of the enneacarbonyl at 100°C : 6Fe2(CO)9 -> 2Fe3(CO)12+6Fe(CO)5 but is now usually prepared from solutions of carbonylferrate anions. One method uses the oxidation of these ions with manganese(IV) oxide followed by acidification and extraction of the carbonyl into petroleum ether. In another method,iron pentacarbonyl is treated with aqueous triethylamine to form the dark red [Et3NH][Fe3(CO)11H] which is then acidified and the carbonyl extracted into petroleum ether.