New Ir and Rh “PNP” aminodiphosphine complexes are effective catalysts in styrene oxidation with tert-butyl hydroperoxide as the oxidant. The Ir catalysts were more active than the Rh catalysts with high yields to benzaldehyde in comparison to styrene oxide.

Two types of cobalt aminodiphosphine complexes have been synthesized and characterized by IR spectroscopy, elemental analyses and single crystal X-ray diffraction. These are [Ph 2 PN(R)PPh 2 ]CoCl 2 , 1 and [Ph 2 P(CH 2 ) 2 N(R)(CH 2 ) 2 PPh 2 ]CoCl 2 , 2 where R ¼ C 6 H 11 (a); C 5 H 11 (b); C 3 H 7 (c). The functional groups on the nitrogen atom (R) were varied from a cyclohexyl ring, to n-pentyl alkyl chain, to an iso-propyl branched substituent. Complexes 2a and 2c were analyzed using single crystal X-ray diffraction. The geometry around the metal centers in 2a and 2c were distorted tetrahedral. All the complexes showed good activity as catalysts for the oxidation of n-octane using tert-butyl hydroperoxide (TBHP) as the oxidant. The complex bearing the flexible ligand backbone with the cyclohexyl substituent on the nitrogen atom was the most active and showed high selectivity towards ketones with 2-octanone being the dominant product.R 1 ¼ 0.0301, wR 2 ¼ 0.0534 Largest diff. peak and hole (eÅ À3 ) 1.035 and À0.804 0.364 and À0.268This journal is

Ir and Rh “PNP” complexes with different ligands are utilized for the oxidation of n-octane. Based on the obtained conversion, selectivity, and the characterized recovered catalysts, it is found that the combination of Ir and the studied ligands does not promote the redox mechanism that is known to result in selective formation of oxo and peroxo compounds [desired species for C(1) activation]. Instead, they support a deeper oxidation mechanism, and thus higher selectivity for ketones and acids is obtained. In contrast, these ligands seem to tune the electron density around the Rh (in the Rh-PNP complexes), and thus result in a higher n-octane conversion and improved selectivity for the C(1) activated products, with minimized deeper oxidation, in comparison to Ir-PNP catalysts.

No abstract

C 30 H 31 NP 2 , monoclinic, CCDC no.: 1452387The crystal structure is shown in the gure. Tables 1-3 contain details of the measurement method and a list of the atoms including atomic coordinates and displacement parameters.