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.

The reactions of cationic carbyne complexes of manganese and rhenium, [η-C 5 H 5 (CO) 2 Mt CC 6 H 5 ]BBr 4 (1, M ) Mn; 2, M ) Re), with diiron anionic compoundsComplexes 1 and 2 also react with [MgBr][Fe 2 (µ-CO)(µ-SeC 2 H 5 )(CO) 6 ] (5) to produce [Fe 2 -(µ-SeC 2 H 5 ) 2 (CO) 6 ] (15) and dimetal bridging carbene complexes [MnFe{µ-C(SeC 2 H 5 )C 6 H 5 }-(CO) 5 (η-C 5 H 5 )] ( 17) and [ReFe{µ-C(SeC 2 H 5 )C 6 H 5 }(CO) 5 (η-C 5 H 5 )] ( 18), respectively. 2 reacts similarly with 16) and a Re-Fe bridging carbene complex [ReFe{µ-C(SeC 4 H 9 -n)C 6 H 5 }(CO) 5 (η-C 5 H 5 )] ( 19), while the analogous reaction of 1 with 6 produced an unexpected trimetal bridging carbyne complex [MnFe 2 (µ-H)(µ-CO) 2 (µ 3 -CC 6 H 5 )CO) 6 (η-C 5 H 5 )] (20). The structures of complexes 9, 10, 13, 18, and 20 have been established by X-ray diffraction studies.