Syntheses and molecular structures of 6-halogeno-pyridin-2-olate complexes with the diruthenium(2+) core

3,3’’-Bis(saccharin-6-ylmethyl)-1,1’:3’,1’’-terphenyl – Precursor of A New Tetradendate Bis-bridging Ligand

“…Unfortunately, a correct elemental analysis could not be obtained, because the solid strongly retained some toluene even when kept at 150 • C/0.001 mbar for one hour. An analogous structure has been postulated for the saccharinato complex [Ru 2 (CO) 5 (µ,µ-sac) 2 ] 2 [12], and the structure of the related complex [Ru 2 (CO) 5 (µ,µ-6-fluoropyridin-2-olate) 2 ] 2 was proven by XRD analysis [31]. Notably, the anticipated precursor to 17, the hexacarbonyl complex [Ru 2 (CO) 6 (µ,µ-tpsac)] (16), could neither be isolated nor observed directly, in contrast to the analogous saccharinato complex [Ru 2 (CO) 6 (µ,µ-sac) 2 ] [12].…”

Diruthenium(I,I) saccharinate complexes: Synthesis, molecular structure, and evaluation as catalysts for carbenoid reactions of diazoacetates

“…In three cases, solvent of crystallization was incorporated in the crystal: 3A · p-xylene, 4 · CH 2 Cl 2 and 5 · 3CH 2 Cl 2 . In all cases, a ''sawhorse'' arrangement, with a cis relationship of the two saccharinate ligands at each metal center, is observed which is characteristic for dinuclear complexes of the general composition [Ru 2 (CO) 4 (l-L) 2 ] (for examples, see literature [12,18,19,21,23,25]). The saccharinate units act as bidentate ligands via their amidate (N-C@O) moiety.…”

“…, 2.609-2.710 Å in complexes with pyridin-2-olate ligands [21,26,27]. A comparison of the Ru-Ru distance in 1 and 3 shows that the strongly coordinating axial CO ligands cause a significant bond lengthening as compared to acetonitrile ligands.…”

“…Although no final structural proof could be obtained so far, we assume that the product represents the tetranuclear ruthenium complex [Ru 2 (l-sac) 2 (CO) 5 ] 2 (2), a coordination dimer of a dinuclear ruthenium complex. Recently, we have established the structure of an analogous complex with fluoropyridonate rather than saccharinate ligands [21]. Obviously, the thermal conversion of 1 into 2 proceeded by expulsion of one axial CO ligand, rearrangement from the head-tail (0,2) to the head-head (1,1) regioisomer and dimerization across a Ru-O bond.…”

Sawhorse-type diruthenium tetracarbonyl complexes

“…This was confirmed by the single-crystal X-ray structure analysis of Ru 2 (CO) 4 (Opy) 2 (pyOH) 2 [55]. Dimers of dinuclear pyridonato-bridged sawhorse complexes [56,57].…”