Metal catalysis in oxidation by peroxides. 24. Extraction of aqueous peroxomolybdenum species into organic media and their reactivity

Abstract

OLGA BORTOLINI, LETANZ~O BRAGANTE, FULV~O Dl FURIA, and G i o~~i o MODENA. Can. J. Chem. 64, 1189 (1986).The effect of the lipophilicity and coordinating ability of neutral ligands, belonging to the classes of phosphoric amides and pyridine oxides, on the extraction of the neutral oxidants molybdenum(V1)-peroxo complexes from an aqueous acidic phase to an organic one, has been studied. The nature of the Mo(V1)-peroxo species present both in aqueous and organic phase has also been investigated. Sizable amounts of mineral acid, added to adjust pH, may be extracted into the organic phase. The various factors affecting this process such as the nature of the acid added, the organic solvent and the neutral ligand, as well as the effect of this feature on the partition of the oxidant between the two phases are briefly discussed.OLGA BORTOLINI, LETANZ~O BRAGANTE, FULV~O Dl FURIA et G i o~~i o MODENA. Can. J. Chem. 64, 1 189 (1986).On a ttudit les effects, sur l'extraction d'oxydants neutres comme les complexes peroxo-molybdkne(VI), du caractkre lipophile et de l'habilitk k coordonner des ligands neutres que possbdent les phosphoramides et les oxydes de pyridine. On a aussi examint la nature des espbces peroxo-molybdkne(V1) tant dans la phase aqueuse que dans la phase organique. De grandes quantitks d'acides minkraux, qui sont ajoutts pour ajuster le pH, peuvent &tre extraites dans la phase organique. On discute brikvement des divers facteurs qui affectent ce processus, tel que la nature de l'acide qui est ajoutk, la nature du solvant organique et du ligand neutre ainsi que l'effet de cette caracttristique sur la rkpartition de I'oxydant entre les deux phases.[Traduit par la revue]

Peptide side-arm derivatives of lariat ethers and bibracchial lariat ethers: syntheses, cation binding properties, and solid state structural data

“…(b) Gokel, G. W.; Gatto, V. J. United States Patent Number 4,597,903, July 1,1986. (c) Gatto, V. J.; Arnold, K. A.; Viscariello, A. M.; Miller, S. R.; Gokel, G. W. Tetrahedron Lett.…”

“…Although it seems reasonable at first to suppose that the amide carbonyl groups would function as donors for hard alkali metal ions, only the ester carbonyl groups do so. 4 A final observation is that each of the 12 subunits in this cyclododecadepsipeptide is chiral and the chirality alternates (d,d,l,l)3. It was our intent at the outset of the lariat ether program to understand these observations and to utilize such knowledge to synthesize simpler structures having the same essential features as valinomycin.…”

Transition Metal Peroxides. Synthesis and Role in Oxidation Reactions*Dedicated, on the occasion of his 80th birthday, to our ‘vitae ac studiorum magister in secunda et in adversa fortuna’ Emeritus Professor Giorgio Modena, Padova University, who showed us the way toward Chemistry.

“…This kind of reaction is usually observed with early transition metal ions having a d 0 configuration, namely Mo(VI), W(VI), Ti(IV) and Re(VII), and is performed under both homogeneous and heterogeneous conditions in the presence of H 2 O 2 (or ROOH) as primary oxidant 371 . Anionic W(VI) and Mo(VI) peroxo complexes, containing either H + 101 372 or a lipophilic cation 102 373,374 , have been employed as effective oxidants of primary and secondary alcohols to carbonyl compounds. Using stoichiometric amounts of 102 in nonpolar solvents, no competition with double-bond epoxidation or aldehyde over-oxidation is observed 374 377 .…”

Catalysis and Activation of Oxygen and Peroxide Delignification of Chemical Pulps: A Review

“…The catalytic effect of molybdate was attributed to its ability to form, under acidic conditions, reactive diperoxo complexes with peroxide (77).…”