acceptor ligands -p (pi), Chemistry

 

Most ligands have a nonbonding electron pair that may react as a donor to empty orbitals on the metal atom. In ligands known as π acids or π acceptors a donor-acceptor communication also happens in the reverse direction. If a ligand has empty orbitals of π type symmetry with respect to the bond axis these may react as acceptors for electrons in filled metal orbitals of the correct symmetry. That is known as back donation. The commonest and simplest π acid ligand is carbon monoxide CO. This reacts as a donor in the normal way, through the acquired lone-pair orbital centered on carbon (the 3σ MO). The π antibonding orbital may also interact with filled d orbitals to produce the π-acceptor interaction. The combination of π-acceptor and σ-donor interaction is sometimes defined as synergic, as the electron wants in opposite directions facilitate each other.

Evidence for the π-acceptor communication comes from various sources.

 

2091_Untitled.png

 

Fig. 1. Bonding in CO complexes showing (a) σ overlap of CO lone-pair with empty metal d orbital, and (b) overlap of CO π* with occupied metal d

orbital.

 

Posted Date: 7/23/2012 7:52:56 AM | Location : United States






Your posts are moderated
Related Questions

De?ne Quoin and Queen closer De?ne Least count. Explain functions of the foundation

properties of halogens

The difference among Threshold energy and average energy of the molecules is known as activation energy.


Coordination complexes are so pervasive that the structure and reactions are defined in many ways, sometimes confusingly. The atom within a ligand that is bonded to the central ato

How To Develop A New Product  The process of developing a new product comprises three phases, namely formulation or recipe development, standardization of processing methods,

Q. Show the Uses of Emulsions? Emulsions provide many useful functions in food preparation and processing. They: 1) act as vehicles for flavour to foods, 2) dilute ingr

what is meant by dumas methad?give its functioning and uses

1. In water softening, which of the precipitates will settle out? 2. For particle sizes larger than 1μ in size 3. In non-ideal type II settling 4.The most usually used me