Calculations at the B3LYP functional and MP2 method using 6-31 G(d,p) basis set reveal that binding affinity of Li+ ion with benzene is enhanced by tri-annelation of benzene or highly strained bicyclo[2.1.1]hexene ring. The substantial increase of interaction energy of benzene-Li+ complex by ring annelation of bicyclo[2.1.1]hexene may be attributed to the weak C-H... Li+ interactions in addition to Li+-pi interaction. Annelation of three bicyclo[2.1.1]hexene rings to benzene yields a good receptor for cation binding. The binding of Li+ with ring annelated benzenes has significant impact on the characteristic vibrational frequencies and NMR chemical shifts. (C) 2007 Published by Elsevier B.V.