Mononuclear and dinuclear complexes with a [Ru(tBu2PCH2CH2PtBu2)(CO)] core

Abstract

Thermolysis of solid [Ru(d(t)bpe)(CO)2Cl2](2, d(t)bpe =(t)Bu2PCH2CH2P(t)Bu2) under vacuum affords the five-coordinate complex [Ru(d(t)bpe)(CO)Cl2] (4), which was shown by X-ray crystallography to contain a weak remote agostic interaction. In solution, 4 can be readily trapped by CO, CH3CN or water to give [Ru(d(t)bpe)(CO)(L)Cl2](L = CO, 2; L = CH3CN, 6; L = H2O, 7). Reaction of 4 with AgOTf/H2O yields the tris-aqua complex [Ru(d(t)bpe)(CO)(H2O)3](OTf)2 (8), which has been structurally characterised and probed in solution by pulsed-gradient spin echo (PGSE) NMR spectroscopy. The water ligands in 8 are labile and easily substituted to give [Ru(d(t)bpe)(CO)(NCCH3)3](OTf)2 (10) and [Ru(d(t)bpe)(CO)(DMSO)3](OTf)2 (11). In the presence of CO, the tris-aqua complex undergoes water-gas shift chemistry with formation of the cationic hydride species [Ru(d(t)bpe)(CO)3H](OTf) (12) and CO2. X-Ray crystal structures of complexes 2, 4, 6, 8 and 11-12 are reported along with those for [{Ru(d(t)bpe)(CO)}2(mu-Cl)2(mu-OTf)](OTf) (3), [{Ru(d(t)bpe)(CO)}2(mu-Cl)3][Ru(d(t)bpe)(CO)Cl3](5) and [Ru(d(t)bpe)(CO)(H2O)2(OTf)](OTf)(9).

Labile Rhodium(I)–N-Heterocyclic Carbene Complexes

“…The 1 H NMR spectrum in CD 2 Cl 2 showed a resonance at 2.83 ppm ascribed to the CH protons of the coe ligand, whereas two doublets for IPr (171.7 ppm, J C–Rh = 71.7 Hz), and the η 2 - olefin (57.1 ppm, J C–Rh = 19.0 Hz) were observed in the 13 C{ 1 H} NMR spectrum. The triflate ligand may occupy the two available vacant sites in a bidentate chelate or bridging fashion . However, the stretching bands for the SO 3 group in the IR spectrum at 1310 and 1181 cm –1 do not clarify the coordination mode .…”

Ion pairing using PGSE diffusion methods

“…All three anions are quite small and their respective r H values most probably represent the solvated anion species. In acetone solution the hydrogen bonding from the anion to the aquo-ligands of the ruthenium dication exerts a strong influence [131][132][133] so that the resulting r H values for the cations are all now are more than 1 Å larger. The anion r H values all change drastically due to the partial association with the fairly large dication.…”

Modelling NiFe hydrogenases: nickel-based electrocatalysts for hydrogen production

“…Carbonyl ligands help stabilizing hydride species through charge delocalization or can react through water-gas shift reaction to generate a hydride ligand. 59 Moreover carbocyclic ligands may stabilize potential ruthenium hydride species through steric protection. Two different nickel precursors [Ni(xbsms)] and [Ni(emi)] 2− (emiH 4 = N,N -ethylenebis(2mercaptoisobutyramide)) 60 were used in order to gain more insight in the structure-function relationships governing the reactivity of this class of compounds.…”