SYNTHESIS, CHARACTERIZATION, AND X-RAY STRUCTURE OF BISfn-ACETATO DICARBONYL(DI-TERI-BUTYLPHOSPHINE) RUTHENIUM (I)]

Sawhorse-type diruthenium tetracarbonyl complexes

“…The two ruthenium atoms show a pseudo-octahedral coordination geometry, one coordination position being the other ruthenium atom. The Ru-Ru distance being 2.728(1) [2] or 2.735(1) Å [3] is in accordance with a metal-metal single bond, as suggested by the electron count of 34, the noble-gas rule requiring indeed 18 + 18 − 2 = 34 electrons for a metal-metal bonded dinuclear complex, the formal oxidation state of ruthenium being +1.…”

“…Schumann et al used refluxing n-butanol as a solvent for the synthesis of Ru 2 (CO) 4 (OOCPr n ) 2 (PBu t 3 ) 2 [2], Jones and co-workers synthesized Ru 2 (CO) 4 (OOCMe) 2 (PBu t 2 H) 2 in refluxing di-n-butyl ether [3] 2Ru 3 (CO) 12 …”

“…1). The molecular structure of the less bulky acetato complex Ru 2 (CO) 4 (OOCMe) 2 (PBu t 2 H) 2 (as di(t-butyl)phosphine derivative), solved by Jones and co-workers in 1988 [3], shows indeed a much less distorted coordination geometry (Fig. 2), which is the case for most diruthenium tetracarbonyl complexes of this type.…”

“…The molecular structures of Ru 2 (CO) 4 (OOCPr n ) 2 (PBu t 3 ) 2 [2] and of Ru 2 (CO) 4 (OOCMe) 2 (PBu t 2 H) 2 [3] are characterized by a dinuclear ruthenium-ruthenium backbone, each ruthenium atom carrying two terminal carbonyl ligands in cis-equatorial positions, in such a way that the Ru 2 (CO) 4 moiety resembles a sawhorse (Fig. 3).…”

“…(1)-(3), complexes which have been isolated and fully characterized [1] 2nRu 3 (CO) 12 +6nRCOOH → 3[Ru 2 (CO) 4 (OOCR) 2 ] n +12nCO + 3nH 2 (1) [Ru 2 (CO) 4 (OOCR) 2 ] n + 2nL → nRu 2 (CO) 4 (OOCR) 2 L 2 (2) Ru 2 (CO) 4 (OOCR) 2 L 2 +2PR 3 → Ru 2 (CO) 4 (OOCR) 2 (PR 3 ) 2 +2L…”