Reactions of Pd and Pt Complexes with Molecular Oxygen

Abstract

Knowledge of exactly how metal complexes react with molecular oxygen is still limited and this has hampered efforts to develop catalysts for oxidation reactions using O2 as the oxidant and/or oxygen-atom source. A better understanding of the reactions of different types of metal complexes with O2 will be of great utility in rational catalyst development. Reactions between molecular oxygen and Pd(0-II) and Pt(0-IV) complexes are reviewed here.

Liquid phase oxidation chemistry in continuous-flow microreactors

“…[5][6][7][8][9][10][11] Furthermore, reaction mechanisms are often complex for oxidation processes. [12][13][14][15] The complexity is further aggravated by complex mass transport processes in e.g., multiphase oxidation processes using oxidants such as oxygen, ozone or hydrogen peroxide. [16][17][18] This is more pronounced in fast oxidations as the reaction rate is in such cases greatly influenced by the mass transfer rate.…”

Oxygenation of a benzyl ligand in SNS-palladium complexes with O2: acceleration by anions or Brønsted acids

“…[1][2][3][4][5][6] The insertion of O2 into a M-C(sp 3 ) bond in transition-metal alkyl complexes have been investigated, mainly limited to first-row metals such as Cr, 7 Fe, 8,9 and Co. [10][11][12] In the case of second and third-row late transition metals, only methylperoxopalladium 13 and platinum [14][15][16] complexes have been successfully captured. On the other hand, the reactions of several late transition-metal alkyl complexes with O2 produce oxygenated organic compounds.…”

A biomimetic phenol substituent effect on the reaction of a dimethylplatinum(ii) complex with oxygen: proton coupled electron transfer and multiple proton relay

“…1 Both metallic platinum and platinum complexes are important in the C-H bond activation and in the oxidation catalysis, and so the reactivity of organoplatinum complexes with oxygen and oxygen atom donors is a topical field of study. However, there are major problems to overcome before such selective reactions as the oxidation of alkanes to alcohols can be realised, and so there is intense research activity into the activation of oxygen with late transition metals.…”

“…However, there are major problems to overcome before such selective reactions as the oxidation of alkanes to alcohols can be realised, and so there is intense research activity into the activation of oxygen with late transition metals. [1][2][3][4][5] Several enzymes that use oxygen, or which convert hydrogen peroxide to oxygen, have tyrosine residues close to the reaction centre, and the phenol functional group of tyrosine is thought to play a role in the proton coupled electron transfer and/or in the proton relay to and from the reaction site. 2,3 The reaction of dimethylplatinum(II) complexes with oxygen in methanol occurs in two steps, each of which can be considered as a proton coupled 2-electron transfer, 4 first to give a hydroperoxide and then a hydroxide complex (Scheme 1, A, B, C), and the reactivity can be enhanced in the presence of an appended Lewis base (Scheme 1, D, E, F).…”

“…However, one methyl substituent of the acetone was doubly deprotonated, and these protons were added to the imine nitrogen to form an amine donor and to the oxygen atom to form a hydroxide group (Scheme 3). [1][2][3] Fig. The addition of acetone to an imine group in organometallic compounds is rare, but there are a few previous examples.…”