1,720,984 research outputs found
Kinetics and mechanism of metallacyclization in a chloromethylcobalt complex with a salen-type ligand.
No full text
Alternative cocrystallization of ‘‘almost ’’enantiomers and true enantiomers in some cis -beta organocobalt salen-type complexes with a amino acids.
No full textSynthesis, Characterization, and Solution Behavior of Optically Active cis beta Organocobalt Salen_Complexes with L-Amino Acids.
No full textThe reaction of a cis â folded organocobalt derivative with a salen-type ligand, 1, isolated as racemic compound of ¢ and ¤ enantiomers, with enantiomerically pure R-L amino acids is reported. The reaction between racemic 1 and L-tyrosine afforded a mixture of the two diastereoisomers ¢-2 and ¤-2, which could be separated by fractional crystallization owing to the lower solubility of ¢-2. The absolute configuration of the two diastereomers was unequivocally assigned from the X-ray structure, using the known absolute configuration of the asymmetric carbon of the amino acid as internal reference. The reaction of racemic 1 with trans-4-hydroxy-L-proline afforded only the diastereoisomer with a ¢ configuration of the tetradentate ligand, as proved by X-ray diffractometric analysis
A Guest-Induced Assembly of a Molecular Box from Methylcobaloxime and 1,4-Phenylenbisboronic acid.
No full textMetal Coordination by Sterically Hindered Heterocyclic Ligands, Including 2-Vinylpyridine, Assessed by Investigation of Cobaloximes
No full textSelf Assembly of Cobaloximes and Rhodoximes with 3-Aminophenylboronic Acid: A Molecular Triangle and a Polymer.
No full textGuest driven self-assembly of a rectangular box from methylaquacobaloxime and 4,4′-biphenyldiboronic acid
No full text
Synthesis, characterization, and electrochemical properties of a new series of inorganic and organometallic Co(III) complexes with a Schiff base ligand derived from tyrosine
No full textA new series of inorganic and organometallic cobalt Schiff base complexes containing the tetradentate ligand [Z-Tyr(3-Ac)-OMe]2en derived from the condensation of two equivalents of protected 3-acetyl- L-tyrosine with one equivalent of ethylenediamine has been synthesized. As the amino acids have L configuration, the resulting ligand is chiral. The complexes have been characterized by 1H and 13C NMR, ESI-MS spectrometry and U.V.-visible spectroscopy. The U.V.-visible spectra recorded in CH2Cl2 show an absorption band at about 650 nm, characteristic of penta-coordinated alkylcobalt(III)(salen), but an evident deviation from the Lambert Beer law in the concentration range 0.20 2.0 10-3 M suggests some kind of association in this solvent. In coordinating solvent the complexes are hexa-coordinated. The equilibrium constants for pyridine ligation in CH3OH decrease with increasing electron-donor power of the axial alkyl group. Cyclic voltammetry studies indicate that after the reduction RCo(III)/RCo(II), the complexes decompose giving a Co(I) species that is stable on the CV time scale and can be reoxidized to Co(II) and Co(III) species. Both the Epa and the Epc values show that the peak potentials are shifted to more negative values with increasing inductive effect of the axial alkyl group
- …
