Polyisobutylene is shown to be a nonpolar phase tag that separates a highly colored salen Cr(III) complex from products but is otherwise kinetically similar to a low molecular weight salen Cr(III) complex in polycarbonate formation by Cr(III)-catalyzed copolymerization of CO2 and cyclohexene oxide.

Mn(II) salen complex immobilized on nano silicagel was prepared by incorporating Mn(II) salen complex into a nanosilica matrix and characterized by TGA, XRD, atomic absorption spectroscopy and was successfully applied as catalyst for the oxidation of alcohols. Oxidation of a series of alcohols in acetonitrile over immobilized Mn(II) salen complex using tetrabutylammonium peroxymonosulfate (TBAO...

Different types of chiral “privileged” ligands 1 and 2 in promoting enantioselective addition of allylating agents to aliphatic and aromatic aldehydes are described. Here, a new concept in the asymmetric allylation reaction is presented. Redox [Cr(Salen)] mediated addition of allyl halides to carbonyl compounds is described, and mechanistic investigations are discussed. These results open acces...

The mechanism of the hydrolytic kinetic resolution (HKR) of terminal epoxides was investigated by kinetic analysis using reaction calorimetry. The chiral (salen)Co-X complex (X = OAc, OTs, Cl) undergoes irreversible conversion to (salen)Co-OH during the course of the HKR and thus serves as both precatalyst and cocatalyst in a cooperative bimetallic catalytic mechanism. This insight led to the i...

Three interconnected catalytic cycles account for the title reaction catalyzed by a bimetallic aluminum(salen) complex and Bu(4)NBr. In the first, Bu(4)NBr acts as a nucleophile to activate the epoxide. In the second, Bu(3)N generated in situ serves to activate CO(2). In the third, the aluminum(salen) complex brings the two activated species together so that the key bonds can be formed intramol...

In the mononuclear salen-type complex, [Er(NO(3))(3)(C(18)H(20)N(2)O(4))], the Er(III) ion is ten-coordinated in a distorted hexa-deca-hedral geometry by six O atoms of three nitrate anions and four O atoms of the salen-like ligand. Inter-molecular N-H⋯O hydrogen bonds occur. The crystal structure is stabilized by inter-molecular C-H⋯O hydrogen bonds.

properly furnished, metal complexes from salen ligands can recognize neutral molecules, 1 and extract alkaline metal ions 2 as well as cations and anions 3 in addition to possessing catalytic properties. The interaction between central metal ions and substrates is much controlled by peripheral groups of ligands. In order to establish design criteria for more effective salen complexes, we prepar...

The kinetics and thermodynamics of oxidation of Methionine and Ethionine by oxo (salen) chromium (V) ion have been investigated by spectrophotometric method in aqueous medium. The presence of water facilitates ligation of water to the Cr centre and forms an active oxidant [H2O (salen) Cr=O] + .The reaction is found to be first order each in the oxidant and the substrate. The presence of H + ion...

A synthetic strategy for the construction of chiral salen ligands bearing two rigid xanthene spacers functionalized with carboxylic acid and ester groups is presented. Suzuki cross-coupling methodology is used to furnish the appropriately functionalized xanthene spacers to a salicylaldehyde, which is subsequently condensed with (1R,2R)-(-)-1,2-diaminocyclohexane to produce salen ligands featuri...