Friday, January 18, 2019

Charge transfer( CT ) or electron donor acceptor(EDA) complexes and their properties.


What is charge transfer( CT ) or electron donor acceptor( EDA) complexes ?

charge transfer (CT) complex or electron donor acceptor (EDA) complex is an association of two or more molecules or different parts of one large molecule in which a fraction of electronic charge is transferred between the molecular entities. 

Most common example of charge transfer ( CT ) or electron donor acceptor (EDA) complex is the association between trimethyl benzene and trinitro benzene .

trimethyl benzene - trinitro benzene


In EDA Complexes there is always a donor molecule and an acceptor. The donor may donate an unshared pair or a pair of electrons in the orbitals of a double bond or aromatic system. 

These have often been called charge transfer complex. But this term implies that the bonding involves charge transfer, which is not always the case, so that the more neutral name EDA complex is preferable.


 
Few another example of chargetransfer ( CT ) or electron donor acceptor( EDA) complexes are,



Properties of charge transfer( CT ) or electron donor acceptor  ( EDA) complexes.


One test for the presence of an EDA complex is the electronicspectrum. These complexes generally exhibit a spectrum. That is not the same as the sum of the spectra of the two individual molecules.

Because the first excited state of the complex is relatively closed in energy to the ground state. There is usually a peak in the visible or near U.V regions and EDA complexes are often colored.

Many EDA complexes are unstable and exist only in solution in equilibrium with their component, but others are stable solid.


In most EDA complexes the donor and acceptormolecules are present in an integral ratio, most often 1:1, but some complexes with non-integral ratios are also known.


Summary:  



What is charge transfer (CT) or electron donor acceptor(EDA) complexes?

Properties of charge transfer (CT) or electron donor acceptor ( EDA) complexes.





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