Formation of (μ-RE)(μ-S^-)Fe₂(CO)₆ and (μ-RE)(μ-Se^-)Fe₂(CO)₆ (E = S, Se) Anions and a Comparative Study of Their Reactions with SO₂Cl₂, ClC(O)ZC(O)Cl (Z = (CH₂)₂, C₆H₄), or p-MeC₆H₄SO₂Cl. Single-Crystal Structures of [(μ-EtS)Fe₂(CO)₆]₂(μ₄-Se) and (μ-EtS)(μ-p-MeC₆H₄SO

Abstract

The CO-bridged anions [(µ-RE)(µ-CO)Fe 2 (CO) 6 ] -reacted with S 8 to form the sulfur-centered anions (µ-RE)(µ-S -)Fe 2 (CO) 6 (4; E ) S, Se), whereas reaction of the anions with Se 8 yielded the selenium-centered anions (µ-RE)(µ-Se -)Fe 2 (CO) 6 (6; E ) S, Se). Interestingly, reaction of 4 with SO 2 Cl 2 afforded the S-S-bonded clusters [(µ-RE)Fe 2 (CO) 6 ] 2 (µ-S-S) (5), whereas reaction of 6 with SO 2 Cl 2 produced the µ 4 -Se clusters [(µ-RE)Fe 2 (CO) 6 ] 2 (µ 4 -Se) (8); clusters 8 could also be produced by the action of anions 6 on succinoyl chloride or p-phthaloyl chloride, while the µ 4 -S clusters [(µ-RE)Fe 2 (CO) 6 ] 2 (µ 4 -S) (9) were generated by reaction of anions 4 with the above organic bis acid chlorides under similar conditions. Also, reaction of 4 (E ) S) with p-MeC 6 H 4 SO 2 Cl gave the µ 4 -S clusters [(µ-RE)Fe 2 (CO) 6 ] 2 (µ 4 -S) (9; E ) S) and the expected Fe 2 S 2 butterfly clusters (µ-RE)(µ-p-MeC 6 H 4 SO 2 S)Fe 2 (CO) 6 ( 10), whereas anion 6 reacted with p-MeC 6 H 4 SO 2 Cl to afford the unexpected SdO-bridged complexes (µ-RE)(µ-p-MeC 6 H 4 SO 2 )Fe 2 (CO) 6 (11) and µ 4 -Se clusters 8. Clusters 11 could be also prepared through direct reaction of the precursor of 6, i.e. [(µ-RE)(µ-CO)Fe 2 (CO) 6 ] -, with p-MeC 6 H 4 SO 2 Cl. For some of these reactions the mechanisms were preliminarily proposed. The structures of 15 new cluster compounds have been characterized by C/H analysis and IR, 1 H NMR, and MS spectroscopy; those of [(µ-EtS)Fe 2 (CO) 6 ] 2 (µ 4 -Se) (8a) and (µ-EtS)(µ-p-MeC 6 H 4 SO 2 )Fe 2 (CO) 6 (11a) have been confirmed by X-ray diffraction analyses.

Synthetic and Structural Studies of [FeFe]-Hydrogenase Models Containing a Butterfly Fe/E (E = S, Se, or Te) Cluster Core. Electrocatalytic H2 Evolution Catalyzed by [(μ-SeCH2)(μ-CH2NCH2Ph)]Fe2(CO)6

“…Actually, this step is very similar to the previously reported intramolecular nucleophilic attack at iron followed by loss of the Fe-bound ligand that occurred in some butterfly Fe/S cluster complexes. , The third step involves extrusion of one Se atom from the seven-membered metallacycle in M 2 to give the more stable six-membered metallacycle (2Fe1Se1N2C)-containing butterfly [2Fe1Se1N1C] complexes 7–9 . The third step is actually similar to the previously reported extrusion of Se from the p -MeC 6 H 4 SO 2 Se-bridged butterfly Fe/E complexes (μ-RE)­(μ- p -MeC 6 H 4 SO 2 Se)­Fe 2 (CO) 6 (E = S or Se) . It should be noted that although this proposed pathway appears to be reasonable, some details for this pathway need to be further studied.…”

“…The third step is actually similar to the previously reported extrusion of Se from the p-MeC 6 H 4 SO 2 Se-bridged butterfly Fe/E complexes (μ-RE)(μ-p-MeC 6 H 4 SO 2 Se)Fe 2 (CO) 6 (E = S or Se). 46 It should be noted that although this proposed pathway appears to be reasonable, some details for this pathway need to be further studied.…”

Formation and Chemical Reactivities of a New Type of Double‐Butterfly [{Fe2(μ‐CO)(CO)6}2(μ‐SZS‐μ)]2−: Synthetic and Structural Studies on Novel Linear and Macrocyclic Butterfly Fe/E (E=S, Se) Cluster Complexes

“…While each of the iron atoms is bonded to three terminal carbonyl ligands, the two sets of three carbonyls attached to Fe(1) and Fe(2) or Fe(3) and Fe(4) are staggered. This macrocyclic molecule can be formally regarded as derived from a previously reported double cluster complex [{Fe 2 (m-EtS)(CO) 6 } 2 (m 4 -Se)] [11] by substitution of one b-H atom of each m-Et group with an ether chain CH 2 OCH 2 -CH 2 OCH 2 CH 2 OCH 2 group. The existence of the ether chain CH 2 (CH 2 OCH 2 ) 3 CH 2 between S(1) and S(2) in macrocyclic compound 10 d has caused apparent changes in parameters of the double cluster core (14) Fe ( , [11] the geometry of Fe 4 S 2 Se in 10 d is severely distorted, evidently due to the presence of short chain CH 2 (CH 2 OCH 2 ) 3 CH 2 group between the two bridged S(1) and S(2) atoms.…”

“…This macrocyclic molecule can be formally regarded as derived from a previously reported double cluster complex [{Fe 2 (m-EtS)(CO) 6 } 2 (m 4 -Se)] [11] by substitution of one b-H atom of each m-Et group with an ether chain CH 2 OCH 2 -CH 2 OCH 2 CH 2 OCH 2 group. The existence of the ether chain CH 2 (CH 2 OCH 2 ) 3 CH 2 between S(1) and S(2) in macrocyclic compound 10 d has caused apparent changes in parameters of the double cluster core (14) Fe ( , [11] the geometry of Fe 4 S 2 Se in 10 d is severely distorted, evidently due to the presence of short chain CH 2 (CH 2 OCH 2 ) 3 CH 2 group between the two bridged S(1) and S(2) atoms. So, it is reasonable that we could not obtain the analogues of 10 d, namely 10 a ± c, in which the shorter chains (CH 2 ) 4 , CH 2 CH 2 OCH 2 CH 2 and CH 2 (CH 2 OCH 2 ) 2 CH 2 would make the double butterfly cluster core Fe 4 S 2 Se too severely distorted to be formed.…”

Synthetic and Structural Studies on Linear and Macrocyclic Pd- and Pt-Bridged Butterfly Fe/S Cluster Complexes

“…The butterfly Fe/S cluster complexes have received great attention in recent years, largely due to their unique structures and varied chemical reactivities, − and particularly their close relationship with [FeFe]-hydrogenases. − In 2010, we reported a simple and convenient one-pot synthetic method, by which three types of (diphosphine)­Ni-bridged butterfly Fe/S complexes were prepared by sequential reactions of the in situ generated one-μ-CO-containing monoanions [(μ-RS)­(μ-CO)­Fe 2 (CO) 6 ] − ( A ) , and two-μ-CO-containing dianions [{μ-S­(CH 2 ) n S-μ}­{(μ-CO)­Fe 2 (CO) 6 } 2 ] 2 – ( B , n = 4; C , n = 3) , with carbon disulfide and various diphosphine-chelated nickel dichlorides. While the first type of such complexes involves a linear (diphosphine)­Ni-bridged double-butterfly Fe/S cluster, the second and third types of such complexes involve macrocyclic (diphosphine)­Ni-bridged double-butterfly or quadruple-butterfly Fe/S cluster, respectively (Scheme ).…”