82532-29-4Relevant academic research and scientific papers
CLUSTER CHEMISTRY. X. PREPARATION OF 1,2-BIS(DIPHENYLPHOSPHINO)ETHANE DERIVATIVES OF Ru3(C0)12: CRYSTAL AND MOLECULAR STRUCTURES OF Ru3(C0)10(μ-Ph2CH2CH2Ph2)
Bruce, Michael I.,Hambley, Trevor W.,Nicholson, Brian K.,Snow, Michael R.
, p. 83 - 92 (1982)
The reactions of dppe with Ru3(CO)12 catalysed by Ph2CO anion radical have been investigated.Under the appropriate conditions Ru3(CO)11(PPh2CH2CH2PPh2) (with only one P atom coordinated), 2(μ-dppe) (with one dppe ligand bridging two Ru3(CO)11 clusters), Ru3(CO)10(μ-dppe) and Ru3(CO)8(μ-dppe)2 (both with dppe bridging Ru-Ru bonds) can all be isolated in good yields.A full X-ray crystallographic analysis of Ru3(CO)10(μ-dppe) shows that it crystallizes in the triclinic system, space group P, a 10.615(2), b 11.769(6), c 16.584(4) Angstroem, α 75.68(2), β 84.59(2), γ 69.64(2)o.The structure was refined to R=0.030, Rω=0.034 using 3558 data with I 2.5 ?(I).The dppe ligand bridges a Ru-Ru bond (2.856(1) Angstroem), occupying equatorial sites on adjacent Ru atoms.Other distances: non-bridged Ru-Ru bonds are 2.855(1), 2.847(1); Ru-P, 2.330(2) Angstroem.
Reactions of Tetranuclear Rhodium-Trirutheniun Clusters with Di- and Tri-phosphines and with Alkynes
Grand, Jean-Luc Le,Lindsell, W. Edward,McCullough, Kevin J.,McIntosh, Calum H.,Meiklejohn, A. Gavin
, p. 1089 - 1100 (2007/10/02)
The compound 1 (cp = η5-C5H5) and an equimolar amount of diphosphine Ph2P(CH2)nPPh2 react at ambient temperature principally with cleavage of the heteronuclear cluster to form several homonuclear rhodium and ruthenium products.Isolated ruthenium clusters are simple phosphine derivatives of or , including Ru3(μ-diphos)2(CO)8> (diphos=dppm or dppe), and 2(μ-diphos)> (diphos=dppe or dppp), and .Reaction of 1 with the triphosphine MeC(CH2PPh2)3 affords hydrido-clusters and (CO)8> 12, the latter formed by elimination of benzene under very mild reaction conditions.The solid-state structure of cluster 12 has been determined by X-ray crystallographic analysis 1/n, a = 19.549(3), b = 14.2462(21), c = 16.429(4) Angstroem, β = 90.271(18) deg, Z = 4, R = 0.051, R' = 0.060> and the geometrical non-rigidity of this asymmetric molecule in solution is revealed by variable-temperature (31)P NMR spectroscopy.Reactions of cluster 1 with alkynes, RCR, (R = Ph or Et), give heteronuclear products, including isomers of and trimetallic clusters (R = Et, n = 7, R = Ph, n = 8); from reaction of 5-C5Me5)> with PhCCPh a related tetranuclear cluster 3(C2R2)(CO)9(η5-C5Me5)> is formed.A new, octahedral heteronuclear cluster is also reported.
Stereochemical Non-rigidity in Rhodium-Triruthenium Clusters studied by Nuclear Magnetic Resonance Spectroscopy
Lindsell, Edward W.,Walker, Neil M.,Boyd, Alan S. F.
, p. 675 - 684 (2007/10/02)
Variable-temperature (v.t.) 1H and 13C n.m.r. studies on tetranuclear clusters (1), (2), and (3) establish various types of stereochemical non-rigidity in solution.Cluster (1) exhibits at least three distinct CO exchange processes: the lowest-energy intramolecular interchange, with δG195 = 35.2 +- 0.3 kJ mol-1, monitored by v.t. 1H and 13C n.m.r., including 13C- two dimensional exchange correlated spectra at 163 K (NOESY sequence), involves a pairwise exchange of eight CO groups resulting from a 'rocking motion' of CO ligands around a single RhRu2 triangular face.Three isomers of cluster (2) are in dynamic equilibrium in solution: one isomer is relatively rigid stereochemically whereas the other two are fluxional and undergo rapid interconversion at all but the lowest temperatures .Two distinct exchange processes are observed for cluster (3): localised site exchange of CO ligands at Ru(CO)3 centres, with δG223++ = 47.5 +/- 1.5 kJ mol-1, and μ-H mobility, with δG164++ = 29.4 +/- 0.2 kJ mol-1.Reactions of (1) with phosphines produce clusters (6) (dppe = Ph2PCh2PPh2), accompained by cleavage products including .Variable-temperature 1H, 13C,and 31P n.m.r. studies indicate that (4) exists in solution in two isomeric forms undergoing slow interconversion at low tmperatures: the major isomer is more fluxional with a lowest-energy exchange related to that in (1) with δG203++ = 38.0 +/- 0.3 kJ mol -1.Clusters (5) and (6) show n.m.r. spectra of stereochemically rigid species in solution at ambient temperature and structures of these complexes are discussed.
