Unusual Reactions of Cationic Bridging Carbyne Complexes of Dimethylsilane-Bridged Bis(η⁵-cyclopentadienyl)diiron Tricarbonyl with Nucleophiles. A Route to Iron−Sulfur Cluster Bridging Carbene Complexes

Abstract

2 (CO) 6 ] (18). Analogous iron-sulfur cluster bridging carbene complexes [Fe 2 (µ-CO)(µ-CAr)(CO) 2 (η 5 -C 5 H 5 ) 2 -(µ-S)(µ-SC 6 H 5 )Fe 2 (CO) 6 ] (19, Ar ) C 6 H 5 ; 20, Ar ) p-CH 3 C 6 H 4 ) can also be obtained by the reactions of diiron cationic carbyne complexes [Fe 2 (µ-CO)(µ-CAr)(CO) 2 (η 5 -C 5 H 5 ) 2 ]BBr 4 (7, Ar ) C 6 H 5 ; 8, Ar ) p-CH 3 C 6 H 4 ) with [(µ-SLi)(µ-SC 6 H 5 )Fe 2 (CO) 6 ]. The structures of complexes 9, 13, 16, and 18 have been established by X-ray crystallography.

Synthesis of Diiron(I) Dithiolato Carbonyl Complexes

“…354–371 Organometallic electrophiles such as [Cp(CO) 2 M≡CPh] + (M = Mn, Re) can also be employed as alkylating agents. 175,345,346,372 The intermediate Fe 2 ( μ -SR)( μ -SM)(CO) 6 can be protonated and oxidatively coupled, affording Fe 2 ( μ -SR)( μ -SH)(CO) 6 and [Fe 2 ( μ -SR)(CO) 6 ] 2 ( μ -S 2 ), respectively. The oxidatively coupled species, which contains an S–S bond, is again susceptible to attack by carbanionic reagents to afford mixed thiolates.…”

Remarkable Reactions of Cyclooctatetraene Diiron‐Bridging Carbyne Complexes with Amino and Amido Compounds: Nucleophilic Addition to and Breaking of the Cyclooctatetraene Ring

“…[22] The C(1) À N bond length of 1.333 (10) , formed by the attack of neutral C 6 H 5 NH 2 on the bridging carbyne carbon atom of 2 followed by deprotonation by the excess of amine. This intermediate is analogous to the diiron-bridging carbene complexes which were obtained from the reactions [15,16] of the diiron-bridging carbyne complexes [Fe 2 (m-CO)(m-CAr)(CO) 2 (2) Complex 21 is an isomer of complex 18. The difference between the two structures arises from the migration of the H atom of the HNC 6 H 5 group in 18 to a carbon atom of the COT ring and coordination of the N atom to Fe (2).…”

“…The X-ray structure shows that products 4 ± 6 are neutral, diiron-bridging carbyne complexes in which an (C 6 H 5 ) 2 N group has added to a central carbon atom of the COT ring on the face anti to the diiron moiety, that is, the same stereoselectivity of many nucleophilic attacks on hydrocarbon ligands in transition-metal complexes. [1e, 14] [15,16] of the diiron-bridging carbyne complexes [Fe 2 (m-CO)(m-CAr)(CO) 2 (1) ä). [9] In 6, the distances from the Fe atoms to the h 3 -and m-C atoms of the C 8 ring are very close to those in [Fe 2 {m-C(OC 2 H 5 )C 6 H 4 CF 3 -p}(CO) 4 [9] 1.809 ä in 6).…”

Syntheses, structures and reactivities of diindenyl-coordinated diiron bridging carbene complexes

“…In light of the common method to synthesize the mononuclear metal Fischer-type carbene complexes, we have previously developed a facile way to prepare diiron bridging alkoxocarbene complexes: carbonyl-bridged diiron complexes, such as [Fe 2 (l-CO)(CO) 4 (g 8 -C 8 H 8 )], [Fe 2 (l-CO) 2 (CO) 2 (g 5 -C 5 H 5 ) 2 ] and [Fe 2 (l-CO) 2 (CO) 2 {SiMe 2 (g 5 -C 5 H 5 ) 2 }], reacted with aryllithium reagents followed by alkylation with alkylating agent Et 3 OBF 4 in aqueous solution at 0°C to give diiron bridging alkoxycarbene complexes [Fe 2 {l-C(OEt)Ar}(CO) 4 (C 8 H 8 )] [6], {l-C(OEt)-Ar}(CO) 2 (g 5 -C 5 H 5 ) 2 ] [7], and {l-C(OC 2 H 5 )-Ar}(CO) 2 {(g 5 -C 5 H 4 ) 2 Si(CH 3 ) 2 }] [8], respectively. Recently, we have shown a new and convenient method for the preparation of dimetal bridging carbene and/or carbyne complexes that is the reactions of diiron cationic bridging carbyne complexes, [Fe 2 (l-CO)(l-CAr)-(CO) 2 (g 5 -C 5 H 5 ) 2 ]-BBr 4 [9], [Fe 2 (l-CO)(l-CAr)(CO) 2 {(g 5 -C 5 H 4 ) 2 Si(CH 3 ) 2 }]-BBr 4 [10], and [Fe 2 (l-CAr)(CO) 4 (g 8 -C 8 H 8 )] [BF 4 ] [11] obtained by treating above corresponding bridging alkoxycarbene complexes with Lewis acid BBr 3 or HBF 4 , with nucleophiles. This offers a useful method for the preparation and structural modification of dimetal bridging carbene complexes.…”

“…For instance, dicyclopentadienyl-coordinated diiron cationic carbyne complexes [Fe 2 (l-CO)(l-CC 6 H 5 )-(CO) 2 (g 5 -C 5 H 5 ) 2 ]BBr 4 reacts with NaN(SiMe 3 ) 2 and Na[M(CO) 5 CN] (M = Cr, Mo, W) to give bridging carbene complex [Fe 2 (l-CO){(l-C(N(SiMe 3 ) 2 )C 6 H 5 )(CO) 2 (g 5 -C 5 H 5 ) 2 }] [12] and bridging carbyne complexes [Fe 2 (l-CO)-(l-CC 6 H 5 )(CO) 2 (g 5 -C 5 H 5 ) 2 NCM(CO) 5 ] [9], respectively, while the analogous reactions of dimethylsilane-bridged biscyclo-pentadienyl diiron cationic carbyne complexes [Fe 2 (l-CO)(l-CAr)(CO) 2 {(g 5 -C 5 H 4 ) 2 -Si(CH 3 ) 2 }]BBr 4 give benzonitrile-coordinated diiron complex [Fe 2 (l-CO) 2 (CO)-NC-C 6 H 5 {(g 5 -C 5 H 4 ) 2 Si(CH 3 ) 2 }] and bridging phenyl (pentacarbonylcyanometal)carbene complexes [Fe 2 [10], respectively.…”