CCL: How can be separate CH-pi and pi-pi interaction?

From: "Ram Shankar S" <ramchemistry2011!=!gmail.com>
Subject: CCL: How can be separate CH-pi and pi-pi interaction?
Date: Tue, 7 Feb 2012 13:22:30 -0500

 Sent to CCL by: "Ram Shankar S" [ramchemistry2011|gmail.com]
 Dear All,
         How can we separate CH-pi and pi-pi interaction into strong, moderate
 and weak based on the bond distance and bond angles (geometrical parameters) in
 pure organic substances? Whether is there any reference available for this?
        On what basis this kind of interactions (CH-pi and pi-pi) is separated,
 and I would like to know how this CH-pi and pi-pi interactions can be classified
 as strong, moderate and weak.Please help me in this regards.
 Thanks in advance
 With Regards,
 RAAM