Cluster chemistry

Spontaneous Si–C bond cleavage in (TriphosSi)-nickel complexes

“…(2) The treatment of complexes 2b and 3b(ClO 4 ) with BF 3 •Et 2 O or BF 4 − does not lead to the formation of complex 5…”

“…3 For example, 1,1-bis(diphenylphosphino)methane (dppm) undergoes thermally oxidative P-C(sp 3 ) bond cleavage to afford Ph 2 P and CH 2 PPh 2 bond fragments. [3][4][5] Likewise, the deprotonation of methylene-bridged bis-phosphines, the oxidative addition of R 2 PCH 3 or its deprotonated congener R 2 PCH 2 Li to metals was reported to afford phosphino methanide (R 2 PCH 2 ) complexes. 6,7 Moreover, Caulton and coworkers reported a transannular Si-C(sp 3 ) coordination in [(PNP)]NiCl (PNP = ( t Bu 2 PCH 2 SiMe 2 ) 2 N) 8 and selective bond cleavage leading to a phosphino methanide fragment coordinated to nickel.…”

P–C and C–H bond cleavages of dppm in the thermal reaction of [Ru3(CO)10(μ-dppm)] with benzothiophene: X-ray structures of [Ru6(μ-CO)(CO)13{μ4-PhP(C6H4)PPh}(μ6-C)] and [Ru4(CO)9(μ3-η2-PhPCH2PPh2)(μ4-η6:η1:η1-C6H4)(μ-H)]

“…The carbonyl polyhedron of 5 is made up 13 terminal carbonyl ligands, together with a semibridging CO predominantly bound to Ru(4) with a secondary interaction to Ru (7) and Ru(3)-P(2) = 2.2906(7) Å }. The transformations of the dppm ligand to l-g 3 -CH 2 PPh(C 6 H 4 )PPh [12], l-g 3 -C 6 H 4 PPh(CH 2 )PPh [14], l 3 -g 3 -(Ph)PCH 2 P(Ph)C 6 H 4 [8] and l 3 -g 3 -CH 2 PPh [11] from the pyrolysis of 1 have been described but the formation of PhP(C 6 H 4 )PPh provides a new example of a tetradentate ligand at a triruthenium center. The spectroscopic data of 5 are consistent with the solidstate structure.…”

“…Recently, we have demonstrated that the unsaturated triosmium cluster [(l-H)Os 3 (CO) 8 {l 3 -g 2 -Ph 2 PCH 2 P(Ph)C 6 H 4 }] reacts with benzothiophene at 139°C to give three triosmium compounds, [Os 3 (CO) 7 (l-PPh 2 )(l-PMePh)(l 3 -g 2 -C 6 H 4 )], [Os 3 (CO) 8 (l-CO)(l 3 -g 2 -PPh(C 6 H 4 )CH 2 PPh)] and [Os 3 (CO) 7 (l 3 -g 2 -PPh(C 6 H 4 )CH 2 PPh) (l 3 -g 3 -C 8 H 5 S)(l-H)] [7]; the first two of which are derived from the activation of P-C and C-H bonds of the diphosphine ligand and do not contain any benzothiophene-derived ligand; whereas, the last compound contains an unusual l 3 -g 2 -benzothienyl ligand (Scheme 1). It is well documented that in addition to their ability to maintain the metal cluster framework intact during chemical reactions the dppm ligand in [Ru 3 (CO) 10 -(l-dppm)] (1) can also undergo C-H and P-C bond cleavage and M-H and M-C bond forming reactions to give many interesting reactions [8][9][10][11]. Adams et al reported the thermal transformation of the coordinated PMe 2 Ph ligands in [Ru 6 (CO) 15 (PMe 2 Ph)(l 6 -C)] to give a series of interesting hexaruthenium carbide complexes [Ru 6 (CO) 13 -(PMe 2 )(l 3 -g 3 -Me 2 PC 6 H 4 )(l 6 -C)], [Ru 6 (CO) 14 (PMe 2 Ph)(lg 2 -MePhPCH 2 )(l 6 -C)(l-H)], [Ru 6 (CO) 14 (l-PMe 2 )(l-g 2 -MePhPCH 2 )(l 6 -C)], and [Ru 6 (CO) 12 (l-PMe 2 ) 2 (l 3 -g 2 -C 6 H 4 )-(l 6 -C)] via C-H and P-H bond cleavages [12].…”

Novel synthesis of two tert-butyl ketenyl phosphinidine ligands on atrinuclear ruthenium framework. X-Ray structure determination of [Ru3(μ-dppm)(CO)7{μ3-PC( CO)But}2]

“…Pyrolysis results in the elimination of benzene from dppm and metallation of one of the remaining phenyl groups. 6 Phosphines readily add to the unsubstituted Ru atom [7][8][9] and internal and terminal alkynes add readily to the ruthenium triangle. 10 As part of a continuing study of the reactivity of the activated cluster 1, the reaction with 2-tert-butyl-1-phosphaalkyne was examined and the results are reported herein.…”