Low-Temperature-Matrix and Room-Temperature-Solution Photochemistry of Ru(CO)₃(dmpe) (dmpe = Me₂PCH₂CH₂PMe₂)

Abstract

The photochemistry of Ru(CO)3(dmpe) (II; dmpe = Me2PCH2CH2PMe2), has been studied by matrix isolation at 12 K and laser flash photolysis with UV−visible and IR detection at ambient temperature. UV photolysis in a matrix results in the formation of Ru(CO)2(dmpe)·S (S = matrix host), which shows two distinctive UV−visible bands with λmax dependent on S (Ar, 410, 600 nm; CH4, 357, 500 nm; Xe, 345, 457 nm). These shifts are the largest yet observed for any matrix-solvated species. The reactions are partially reversed by long-wavelength (λ > 420 nm) photolysis. Laser flash photolysis in heptane solution (λexc = 266 or 308 nm) with IR or UV−visible detection reveals that Ru(CO)2(dmpe)·heptane is a short-lived fragment which decays rapidly by reaction with Ru(CO)3(dmpe) (k 2 ≈ 1 × 109 dm3 mol-1 s-1). Steady-state photolysis of II in heptane in the presence of hydrogen or triethylsilane yields Ru(CO)2(dmpe)H2 and Ru(CO)2(dmpe)(SiEt3)H, respectively, which have been characterized by IR and NMR spectroscopy.

The reaction of M(CO)3(Ph2PCH2CH2PPh2) (M = Fe, Ru) with parahydrogen: probing the electronic structure of reaction intermediates and the internal rearrangement mechanism for the dihydride products

“…On a longer timescale, reaction with H 2 leads to the generation of the stable complex Ru(CO) 2 (dmpe)(H) 2 . 34 We have described how this route can be used to prepare the analogous complex, Ru(CO) 2 (dppe)(H) 2 (1) from the readily accessible precursor Ru(CO) 3 (dppe) and then extended this approach to Fe(CO) 3 (dppe) and hence prepared Fe(CO) 2 (dppe)(H) 2 .…”

Do early and late transition metal noble gas complexes react by different mechanisms? A room temperature time-resolved infrared study of (η5-C5R5)Rh(CO)2 (R = H or Me) in supercritical noble gas solution at room temperature

“…2 Using a similar method, Perutz and Turner 3 generated M(CO) 5 (L) (M = Cr, Mo, or W; L = Xe, Kr or Ar) from the photolysis of M(CO) 6 in matrices at 20 K. Matrix isolation has since become a powerful technique for the characterization of organometallic noble gas complexes 4 including fac-(η 2 -dfepe)Cr(CO) 3 (L) (dfepe = (C 2 F 5 ) 2 PCH 2 -CH 2 P(C 2 F 5 ) 2 ; L = Ar or Xe), 5 CH 3 Mn(CO) 4 (Ar), 6 KrMn-(CO) 5 , 7 Fe(CO) 4 Xe, 2 [KrFe(CO) 5 ] ϩ , 7 Ru(CO) 2 (PMe 3 ) 2 (L) (L = Ar or Xe) 8 and Ru(CO) 2 (dmpe)(L) (dmpe = Me 2 PCH 2 -CH 2 PMe 2 ; L = Ar or Xe). 9 Recently laser ablation and matrix isolation have been combined to characterize the first noble gas-actinide complexes, CUOL (L = Ar, Kr or Xe). 10 However matrix isolation does not provide the kinetic information needed to quantify the reactivity of these unstable species.…”

A combined parahydrogen and theoretical study of H2 activation by 16-electron d8 ruthenium(0) complexes and their subsequent catalytic behaviour

“…On a longer timescale, reaction with H2 leads to the generation of the stable complex Ru(CO)2(dmpe)(H)2. 59 When the reaction is carried out in toluene, the photochemical formation of a second isomer of this species, ciscis-cis Ru(CO)2(L)2(H)2, does occur. Previous work has shown that this product is stable in its own right when L = AsMe2Ph, [12][13] but with phosphine ligands this minor isomer is only observed when Ru(CO)2(L)2(H)2 is warmed with p-H2, at which point the signal amplification of the associated hydride resonances allows its detection.…”

“…On a longer timescale, reaction with H 2 leads to the generation of the stable complex Ru(CO) 2 (dmpe)(H) 2 . 59 When the reaction is carried out in toluene, the photochemical formation of a second isomer of this species, cis-cis-cis Ru(CO) 2 (L) 2 (H) 2 , does occur. Previous work has shown that this product is stable in its own right when L = AsMe 2 Ph, 12,13 Scheme 4 Proposed catalytic cycle for hydrogenation of diphenylacetylene by cct-2-PPh 3 .…”