Re: Re: Why is there a triple bond in CO and NO+?

In the Lewis approach, the drive to fulfill the octet rule often 
superceeds the placement of formal charges on the proper atoms.

The Valence Bond description uses hybrid atomic orbitals but it is more 
a "description of what" rather than an "explanation of why."

Rather than including a long descriptionfor an answer, I will defer to 
the following web site:
  http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch8/mo.html#exist


It gives a description of the molecular orbital (MO) approach.  One can 
follow the description for the O2 molecule found there.  CO and NO+ have 
two less electrons than O2.  Whereas the bond order for O2 is calculated 
as 2, the bond order for CO and NO+ will be 3 (two less electrons in 
antibonding orbitals) and this corresponds to a triple bond.

That is probably the best description of the triple bond in these 
molecules.