Synthesis, characterization and electrocatalytic H-2 production of base-containing Fe/S and Fe/Se clusters

Reaction of base-containing diphosphine ligand NP2S (NP2 =(Ph2PCH2)(2)NCH3) with [Fe-3(CO)(12)] in THF at room temperature forms [{Fe-2(CO)(6)(mu-PPh2)}(2)(mu(4)-S-2)] (1) and [Fe-3(CO)(8)(mu 3-S)(2){kP-PPh2CH2N(CH3) CH2P(= S)Ph-2}] (2) resulting from P-S bond cleavage and PeFe bond formation. Similarly, NP2Se reacts with Fe-3(CO)(12) to provide [{Fe-2(CO)(6)(mu-PPh2)}(2)(mu(4)-Se-2)] (3) and [Fe-3(CO)(7)(mu(3)-Se)(2){k(2)P, P-(PPh2CH2)(2)NCH3}] (4). All the compounds have been completely characterized by elemental analyses, IR, H-1 NMR, C-13 NMR and P-31 NMR spectroscopy and structurally determined by X-ray crystallography. Electrochemical studies reveal that when using HOAc or TFA as a proton source, 2 and 4 exhibit catalytic H-2 production.