112834-95-4Relevant academic research and scientific papers
New Bonding Mode of Tricyclohexylphosphoniothiocarboxylate (S2CPCy3) as an Eight-electron Donor. Synthesis, Reactivity, and X-Ray Crystal Structure of
Miguel, Daniel,Riera, Victor,Miguel, Jesus A.,Solans, Xavier,Font-Altaba, Manuel
, p. 472 - 474 (1987)
The reaction of Mn2(CO)10 with the tricyclohexylphosphine-carbon disulphide adduct S2CPCy3 in refluxing toluene affords the dinuclear complex (1) in good yield, the structure of which, determined by X-ray crystallography, shows a new mode of co-ordination of the S2CPCy3 ligand which is bonded to an Mn atom by two sulphur atoms and to the other Mn atom by two sulphur and one carbon atom donating 8 electrons; thermal reactions of (1) with neutral monodentate ligands L yield via CO displacement.
Trialkylphosphine-carbon disulfide adducts as eight-electron bridging ligands. X-ray structures of [Mn2(CO)6(μ-S2CPCy3)] and [Mn2(CO)4(μ-S2CPCy3)(μ-dppm)]
Miguel, Daniel,Riera, Víctor,Miguel, Jesús A.,Gómez, Montserrat,Soláns, Xavier
, p. 1683 - 1692 (2008/10/08)
Carbon disulfide adducts of bulky trialkylphosphines, such as PCy3 or PPri3, react with Mn2(CO)10 to give dimanganese hexacarbonyl complexes [Mn2(CO)6(S2CPR3)]. An X-ray determination of the structure of the derivative with S2CPCy3 (1a, triclinic, space group P1, a = 11.652 (4) ?, b = 11.368 (3) ?, c = 10.973 (3) ?, α = 85.76 (2)°, β = 77.29 (2)°, γ= 86.00 (2)°, Z = 2, R = 0.061, Rw = 0.064) showed that the ligand adopted a new bonding mode, which can be described as η2(S,?) chelate to one manganese and η3(S,C,S′) pseudoallyl to the other manganese, thus bridging unsymmetrically the Mn-Mn bond and donating 8 e to the metals. The analysis of the bond distances within the Mn2S2C core suggests a strong interaction between the S2C group and the metal atoms. This is confirmed by the high thermal stability of the 8e bridge, which permits the preparation of a variety of derivatives [Mn2(CO)5(L)(μ-S2CPR3)] and [Mn2-(CO)4(L)2(μ-S2CPR 3)] by carbonyl substitution reactions requiring high temperatures. Thus, the thermal robustness of the 8e bridge has been proved by the X-ray structure determination of the derivative [Mn2(CO)4(μ-dppm)(S2CPCy3)] (4e), which has to be prepared by heating the parent hexacarbonyl (1a) and dppm in refluxing xylene for 30 h. (4a is triclinic, space group P1, a = 16.403 (4) ?, b = 14.927 (3) ?, c = 11.903 (3) ?, α = 116.48 (3)°, β = 106.46 (3)°, γ = 81.49 (2)°, Z = 2, R = 0.039, Rw = 0.044). 13C NMR spectra display the signal of the central carbon of the S2CPR3 ligand in the range δ 79.19-85.51 ppm, being therefore a very useful tool for the characterization of this type of bridge. A close inspection of the structures suggests an alternative view of the bonding, consisting of a nearly planar η4-Mn-S-C-S ring which donates (formally) 5 electrons to the second manganese atom. A comparison of the structural parameters of the molecules with those known for cymantrene, cymantrene-like, and η3-allyl compounds is given.
