Syntheses and X-ray structures of the bridging and chelating isomers of Os3(CO)10(dmpe)

Synthesis and diphosphine ligand fluxionality in Os3(CO)10(bmi): Kinetic evidence for nondissociative diphosphine isomerization and X-ray crystal structure of 1,1-Os3(CO)10(bmi)

“…Accordingly, the 2c that is observed in our synthetic reactions must arise from the direct substitution of 1 with bmi. The behavior exhibited by 1 in its reaction with bmi is similar to the bimodal substitution attendant in the reaction of cluster 1 with the diphosphine ligand dmpe, which affords the two clusters 1,2-Os 3 (CO) 10 (dmpe) and 1,1-Os 3 (CO) 10 (dmpe) as a non-interconverting isomeric mixture [24]. Heating the initial cluster mixture containing 2b, 2c, and 3 in toluene at 60°C in a thermostated bath for 24 h led to the complete consumption of 2b and the formation of an 83:17 mixture of clusters 2c and 3 as determined by 1 H NMR spectroscopy [25].…”

Chelate and Bridge Diphosphine Isomerization: Triosmium and Triruthenium Clusters Containing 1,1‘-Bis(diphenylphosphino)ferrocene (dppf)

“…To confirm this assertion and to compare the structures with those of the chelate and bridge isomers of [Os 3 (CO) 10 (dppv)] 19 and [Os 3 (CO) 10 (dmpe)] reported by Richmond and Watson, we undertook X-ray crystallographic studies of both 2 and 3 . The molecular structure of 2 is shown in Figure and, selected bond distances and angles are listed in the caption.…”

“…The dppf ligand bridges the Os(1)−Os(1A) edge, occupying adjacent equatorial coordination sites the phosphine moieties lying trans to the nonbridged osmium−osmium edges [P(1)−Os(1)−Os(2) = 170.27(3) o ]. The dppf bridged vector [Os(1)−Os(1A) = 2.9507(4) Å] is significantly longer than the nonbridged osmium−osmium bonds, which is in contrast to the situation in [Os 3 (CO) 10 (μ-dppe)] [2.891(1) vs 2.878(1), 2.871(1) Å] 17 and [Os 3 (CO) 10 (μ-dmpe)] [2.8832(6) vs 2.8819(6), 2.8817(6) Å] . The osmium− phosphorus bond distances [Os(1)−P(1) = 2.3425(10) Å, Os(1)−P(2) = 2.3284(10) Å] are almost the same as those in 2 and [Os 3 (CO) 10 (μ-dppe)] [2.328(3) and 2.333(3) Å] .…”

Ligand degradation and phosphorus scavenging in the reaction between 1,2-bis(diphenylphosphino)benzene (dppbz) and Ru6(μ6-C)(CO)17: Synthesis and X-ray structure of the edge-bridged square-pyramidal cluster HRu6(μ5-C)(μ3-P)(CO)14(dppbz)

“…The title cluster consists of a square-pyramidal Ru 5 core that is edged-bridged by the sixth ruthenium atom and whose polyhedral structure is in keeping with its 88-electron count and structural trends exhibited by other condensed Table 2 Selected bond distances (Å ) and angles (°) for HRu 6 (l 5 -C)(l 3 -P)(CO) 14 (dppbz) polynuclear clusters [13,14]. The Ru-Ru bond distances range from 2.6703(9) Å [Ru(2)-Ru (3)] to 2.902(1) Å [Ru(4)-Ru (5)] and exhibit a mean distance of 2.830 Å that is in agreement with those Ru-Ru distances found in other carbide-containing Ru 5 and Ru 6 clusters [1,11,15]. Although the bridging hydride was not located during refinement, it has been assigned to the long basal Ru(4)-Ru (5) vector.…”

“…In comparison to the extensive literature examples that exist for dppm-, dppe-, and dppf-substituted polynuclear compounds, metal clusters containing a dppx or dppbz ligand are essentially nonexistent. The synthesis and structural characterization of the double homometallic cluster [Ru 6 (l 6 -C)(CO) 16 ] 2 (dppx) and its thermal conversion to the pincer-bridged cluster Ru 6 (l 6 -C)(CO) 15 (dppx) have recently been reported by us [5]. Herein we present our data on the reaction between Ru 6 (l 6 -C)(CO) 17 and the diphosphine ligand dppbz to give HRu 6 (l 5 -C)(l 3 -P)-(CO) 14 (dppbz).…”