Reactions between Fe I I I , dppm, CO as appropriate and LiAlH 4 produce the Fe I I complexestrans -[Fe(Cl)(CO)(η 2 -dppm) 2 ][FeCl 4 ]. (1a)trans -[Fe(H) 2 (η 2 -dppm) 2 ] (2) and trans-[Fe(H)(Cl)(η 2 -dppm) 2 ] (3), depending upon the reaction conditions. The trans octahedral structures, with chelating dppm ligands, of 1a and 2 have been established by X-ray crystallography. Compound 2 reacts with CO to produce the Fe 0 complex Fe(CO) 3 (η 1 -dppm) 2 (4), identified by NMR spectrometry, and with H 2 /HBF 4 Et 2 O to give the dihydrogen complex trans-[Fe(H)(η 2 -H 2 )(η 2 -dppm) 2 ]BF 4 (5). The dihydrogen can be replaced with, for example, CO and CH 3 CN to give trans-[Fe(H)(L)(η 2 -dppm) 2 ]BF 4 (L = CO, 6, and L = CH 3 CN,7 , respectively). With CS 2 , insertion into the Fe--bond of 5 occurs to produce the dithioformato complexcis -[Fe(η 2 -S 2 CH)(η 2 -dppm) 2 ]BF 4 (8), the structure of which is also reported.