Ethylenediamine Copper Complex Research Articles

Time-Resolved Continuous-Wave and Pulse EPR Investigation of Photoinduced States of Zinc Porphyrin Linked with an Ethylenediamine Copper Complex

Electron spin dynamics of the photoexcited state of a new porphyrin system built of a zinc porphyrin molecule with a linked complex of copper ion (ZnPCu) was studied using electron paramagnetic resonance (EPR) methods. The time-resolved continuous-wave and echo-detected EPR data show that electron spins of the ZnPCu system are polarized. The shape of the EPR spectrum and the echo-detected nutation spectroscopy data indicate that there is a relatively small spin–spin interaction between two subunits, namely, less than the zero-field splitting parameter of the excited triplet ZnP molecule. Results have been interpreted assuming that the S = 1 Zn porphyrin subunit electron spins are polarized via the triplet mechanism and this polarization is transferred to the S = 1/2 copper subunit via a flip-flop process induced by the exchange interaction between these subunits. The formation of the integral spin polarization in the triplet–doublet system as a function of the value and type of the triplet–doublet interaction was analyzed.

Efficient and selective copper-grafted nanoporous silica in aqueous conversion of aldehydes to amides

The one-pot conversion of aldehydes to their corresponding primary amides has been studied using SBA-15-grafted ethylenediamine copper complexes (En–Cu).

REMOVAL OF CHROMIUM, COPPER, CADMIUM AND LEAD IONS FROM AQUEOUS SOLUTIONS BY DIATOMACEOUS EARTH

This paper presents the uptake of Cr3+, Cu2+, Cd2+ and Pb2+ from aqueous solutions on diatomaceous earths. The mineral was characterized by XRD and XRF spectroscopy. Surface areas were determined using BET and Methylene Blue sorption methods. Cation exchange capacity (CEC) was estimated using the ethylenediamine copper complex. Batch experiments were carried out at pre determined equilibration time, adsorbent amount, pH, temperature and initial metal cation concentration. The systems were investigated at 298.15, 308.15 and 318.15 K using Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherms. Best fits were obtained with Langmuir plots for Cr3+, Cd2+ and Pb2+ while Cu2+ obeyed more closely Freundlich isotherm. Apparent thermodynamic parameters .G, .H and .S were obtained from the temperature dependence of Langmuir K values. The .H values indicated that the removal of these cations from water is enthalpically favorable (exothermic reaction) and therefore in most cases the extraction is enthalpy controlled given the loss of entropy observed in all cases with the exception of Cd2+.

ChemInform Abstract: Highly Enantioselective Henry Reaction Catalyzed by a New Chiral C2‐Symmetric N,N′‐Bis(isobornyl)ethylenediamine—Copper Complex.

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Highly enantioselective Henry reaction catalyzed by a new chiral C2-symmetric N, N′-bis(isobornyl)ethylenediamine–copper complex

A new chiral C 2-symmetric N, N′-bis(isobornyl)ethylenediamine–copper complex is found to be an efficient catalyst in the enantioselective Henry reaction between nitromethane and various aldehydes to provide β-hydroxy nitroalkanes with high chemical yield (up to 95%) and high enantiomeric excess (up to 90%).