Reactions of peroxobis(triphenylphosphine) platinum (II) and analogs with with carbon dioxide, carbon disulfide, and other unsaturated molecules

Abstract

Adducts of C02, CS2, CO, aldehydes, ketones, acetone oxime, and thiourea with peroxobis(triphenylphosphine)platinum(II) and analogs (or the corresponding tetrakisphosphineplatinum(O) complex in the presence of oxygen) have been prepared. Most of the adducts are thought to have a five-membered ring structure involving a peroxo group, and the reactions of these adducts, particularly with reducing agents, have been studied. It has been shown that in many cases, the five-membered peroxo-containing ring can be reduced to a fouror three-membered ring without a peroxo group. The original adducts are characterized by the disappearance of the unsaturated infrared stretching frequency [y(C=0), v(C=S), or y(C=N)], and for most of the compounds, the infrared vibrations

Unique Evidence for a RhIII to RhI Reduction by Deoxygenation of a Carbonate Moiety to CO2 by an Out-of-Sphere Phosphane

“…[1,2] They are usually prepared by reaction of metal dioxygen complexes with CO 2 . Accordingly, Rh III peroxocarbonates are easily obtained according to Equation (1).…”

“…[1,2] They are usually prepared by reaction of metal dioxygen complexes with CO 2 . Accordingly, Rh III peroxocarbonates are easily obtained according to Equation (1). Alternatively, transition metal carbon dioxide complexes can react with dioxygen [3,4] to afford peroxocarbonates.…”

“…Alternatively, transition metal carbon dioxide complexes can react with dioxygen [3,4] to afford peroxocarbonates. (1) By using labelled species, we have recently shown that CO 2 reacts with Rh(η 2 -O 2 ) complexes by insertion into the OϪO bond (Scheme 1, path A), rather than by insertion into the MϪO bond (Scheme 1, path B). [5] The reaction pathway has been demonstrated through coupling an IR theoretical study (calculation of the vibrational frequencies of selected bonds of the peroxocarbonate complexes) with experimental vibrational frequencies.…”

Rhodium Derivatives of Peroxoboronic Acids and Peroxoboric Acid: Formation of Metallatrioxaborolanes from an η2‐Peroxo Complex

“…The absorption at 654 cm À1 (644 cm À1 for 2') and the isotopic shift are also indicative of the presence of the peroxo unit. [7,12] Two other bands at 572 cm À1 (556 cm À1 for 2') and 477 cm À1 (463 cm À1 for 2') may be assigned to relatively pure Rh À O antisymmetric and symmetric vibrations. [13] The latter can be seen only in the Raman spectrum.…”

Structures of Transition States in Metal‐Mediated O2‐Activation Reactions

“…[4] The formation of h 2 -peroxide compounds is characterized by 18 O KIEs that are less than the EIEs (K 16,16 /K 18,16 ) calculated from Bigeleisens formalism [25] using normal mode stretching frequencies. [26][27][28][29] Although the products are structurally quite different, they exhibit similar shifts of oxygen-isotope-dependent stretching frequencies resulting in a narrow range of (K 16 18,16 . [4][5][6][7] For inner-sphere electron transfer (ET), in which new bonds are formed during the redox reaction, the productlike character of the transition state can be defined in terms of the ratio of the 18 À1] is expected to correlate with the barrier height (DG°/ log k O 2 ) when the reaction coordinate includes the reorganization of bonds involving oxygen nuclei.…”