Carbon monoxide substitutions by trimethyl phosphite in diiron dithiolate complex: Fe-Fe bond cleavage, selectivity of the substitutions, crystal structures and electrochemical studies

Abstract

The reaction of substitution of carbon monoxide by P(OMe) 3 in the complex (µη 2 PhC(S)=C(S)Ph)Fe 2 (CO) 6 1 under thermal activation afforded two colored compounds: a binuclear disubstituted complex (µ-PhC(S)=C(S)Ph)Fe 2 (CO) 4 [P(OMe) 3 ] 2 2 and a mononuclear iron disubstituted complex (η 2 PhC(S)=C(S)Ph)Fe(CO)[P(OMe) 3 ] 2 3. Mass spectrometry, 1 H NMR, IR and electrochemical studies established that two (CO) have been substituted by P(OMe) 3 in complexes 2 and 3. The X-ray studies show that the two P(OMe) 3

Synthesis of Mono- and Diiron Dithiolene Complexes as Hydrogenase Models by Dithiolene Transfer Reactions, Including the Crystal Structure of [{Ni(S2C2Ph2)}6]

“…In a very recent paper, a contrasting result to ours was obtained by Mousser and co-workers . Treatment of 1 with P­(OMe) 3 in toluene at 45 °C gave mono- and disubstituted dinuclear species analogous to 4 and 5 , but instead of a monosubstituted analogue of 3 , the disubstituted mononuclear complex [Fe­(CO)­{P­(OMe) 3 } 2 (S 2 C 2 Ph 2 )] was obtained.…”

“…48,65−68 In a very recent paper, a contrasting result to ours was obtained by Mousser and co-workers. 69 Treatment of 1 with P(OMe) 3 in toluene at 45 °C gave mono-and disubstituted dinuclear species analogous to 4 and 5, but instead of a monosubstituted analogue of 3, the disubstituted mononuclear complex [Fe(CO){P(OMe) 3 } 2 (S 2 C 2 Ph 2 )] was obtained. This compound adopts a structure somewhat more toward trigonal bipyramidal (τ = 0.44) in which both phosphite ligands occupy equatorial positions, the dithiolene ligand spans the axial and equatorial sites, and the CO is in the remaining axial position.…”

“…The electrochemical behavior of 1 was reported recently . The cyclic voltammogram of complex 3 is shown in Figure .…”

“…48,[65][66][67][68] page 10 In a very recent paper a contrasting result to ours has been obtained by Mousser and coworkers. 69 48,60 Since it appeared that 1 may be formed by the reaction of [Fe(CO) 3 (S 2 C 2 Ph 2 )] with additional [Fe(CO) 5 ], we also attempted to prepare the monosubstituted complex 4 by the reaction of complex 3 with an excess of [Fe(CO) 5 ] and Me 3 NO. Although 4 was formed in 39% yield, the major product was the unsubstituted complex 1 (51%).…”

“…The electrochemical behavior of 1 was reported recently. 69 The cyclic voltammogram of complex 3 is shown in Figure 5. The compound displays a reversible reduction wave at Ð 1.359 V (vs. Fc/Fc + ) as well as some more complex oxidation behavior.…”