Dichloro(1-2:5-6-η-cyclooctatetraene)palladium(II)

Synthesis, Structure, and Fluxional Behavior of Bis(cyclooctatetraene)ruthenium(0) and Its Derivatives

“…In the tub-shaped (1,2,5,6-η)-rings, the separations between the metal atom and the coordinated olefinic carbon atoms fall into distinct pairs, Ru−C(1), Ru−C(6) 2.18−2.20 Å and Ru−C(2), Ru−C(5) 2.22−2.24 Å. As expected, the coordinated CC distances are greater in all cases by 0.05−0.10 Å than the uncoordinated ones, as found also in PdCl 2 ((1,2,5,6-η)-C 8 H 8 ) …”

Novel (R2PC2H4PR2)M0−COT Complexes (M = Pd, Pt) Having Semiaromatic η2-COT or Dianionic η2(1,4)-COT Ligands

“…This η 2 -COT complex is highly fluxional even in the solid due to a rapid exchange of coordinated and noncoordinated CdC bonds. 9a,14 With regard to the mechanism of the exchange process we suggest that in solution the complexes pass through T-4 (R 2 PC 2 H 4 PR 2 )Pd{η 4 (1-4)-C 8 H 8 } (low-energy route; Figure 1a) or T-4 (R 2 PC 2 H 4 PR 2 )Pd{η 4 (1,2,5,6)-C 8 H 8 } transition states 15 (high-energy route; Figure 1b), whereas in the solid state merely the low-energy route (Figure 1a) appears to be likely because it involves the least motion of the COT ligand. Similar structural dynamics have been described for the Ni 0 derivatives.…”

“…Cyclooctatetraene complexes of Pd and Pt are rather scarce. (C 8 H 8 )PtCl 2 1 was reported in 1953, but in the meantime apparently only {η 4 (1,2,5,6)-C 8 H 8 }PdCl 2 2 and {µ-η 4 (1,2,5,6):η 4 (3,4,7,8)-C 8 H 8 }(PtMe 2 ) 2 3 have been structurally characterized. 4 The yellow complexes (dppf)Pd 0 -(C 8 H 8 ) 5 and (dppf)Pt 0 (C 8 H 8 ) 5b and some related compounds have only been generated in solution.…”

“…The latter is also formed from [(d i ppe)Pt(cod)] + (565) by elimination of the cod ligand. In addition, the molecular ion may first extrude the bridging cod ligand to afford the dinuclear ion [(d i ppe) 2 Pt 2 ] + (914), which subsequently splits into the base ion [(d i ppe)Pt] + .…”

Crystal structures of dichloro((1,2,5,6-Ƞ)-1,3,5,7-cyclooctatetraene)- platinum(II), PtCl2(C8H8), and diiodo((1,2,5,6-Ƞ)-1,3,5,7-cyclooctatetraene) platinum(II), PtI2(C8H8)

“…Crystals suitable for X-ray structure analysis were obtained via slow evaporation from aCH 2 [2]. In the complexes, the central Ptatoms are in asquare-planar environment defined by the two X atoms and the two midpoints ( M 1, M 2) of the p -coordinated double bonds of the 1,3,5,7-cyclooctatetraene (cot) ligand ( M 1and M 2denote the midpoints of the olefinic bonds C1-C2and C5-C6, respectively).…”