The [Et 3 NH] + salts of μ-CO anions [(μ-RE)(μ-CO)Fe 2 (CO) 6 ] - (E=S, Se) prepared from Fe 3 (CO) 1 2 , REH (R=S,Se) and Et 3 N reacted with μ-S 2 Fe 2 (CO) 6 and subsequent treatment of the intermediate [Et 3 NH] + salts of S-centered anions (μ-RE)(μ-S - )[Fe 2 (CO) 6 ] 2 (μ 4 -S) with MeI, PhCH 2 Br, p-(BrCH 2 ) 2 C 6 H 4 or 1,3,5-(BrCH 2 ) 3 C 6 H 3 to give a series of μ 4 -S-containing double and multiple butterfly clusters (μ-RE)(μ-MeS)[Fe 2 (CO) 6 ] 2 (μ 4 -S) (7-9, RE=t-BuS, PhSe, p-MeC 6 H 4 Se), (μ-p-MeC 6 H 4 Se)(μ-PhCH 2 S)[Fe 2 (CO) 6 ] 2 (μ 4 -S) (11), {(μ-t-BuS)[Fe 2 (CO) 6 ] 2 (μ 4 -S)} 2 [(μ-p-(SCH 2 ) 2 C 6 H 4 ] (12) and {(μ-t-BuS)[Fe 2 (CO) 6 ] 2 (μ 4 -S)} 3 [μ-1,3,5-(SCH 2 ) 3 C 6 H 3 ] (13), whereas the [MgBr] + salts of μ-CO anions [(μ-RTe)(μ-CO)Fe 2 (CO) 6 ] - prepared from Grignard reagents RMgBr and elemental Te followed by treatment of the intermediates RTeMgBr with Fe 3 (CO) 1 2 , reacted with S 2 Cl 2 to afford a series of RTe-containing and μ-S-S-μ bridged double butterfly clusters [(μ-RTe) Fe 2 (CO) 6 ] 2 (μ-S-S-μ) (14-17, R=Et, i-Bu, Ph, p-MeC 6 H 4 ). Similarly, the RTe- and μ 4 -S-containing double butterfly cluster (μ-p-MeC 6 H 4 Te)(μ-MeS)[Fe 2 (CO) 6 ] 2 (μ 4 -S) (10) could be prepared by reaction of the [MgBr] + salt of μ-CO anion (μ-p-MeC 6 H 4 Te)(μ-CO)Fe 2 (CO) 6 ] - with μ-S 2 Fe 2 (CO) 6 followed by treatment with MeI. All these new clusters 7-17 have been characterized by combustion analysis, IR, 1 H-NMR, 7 7 Se-NMR and 1 2 5 Te-NMR spectroscopies, as well as by X-ray diffraction analyses for 9 (RE=p-MeC 6 H 4 Se) and 12 (RE=t-BuS).