Anion-ʌ Interaction inC۶H ۳X…M- (X = H, F, CN, CH۳,and NH۲;M=Au, A g, and Cu) Complex es

In the la st two decad es the role of noncovalent interaction in nature was fully recognized. In biology, these intera ctions are the basis of a great deal of proce sses, whose efficiency is always significant. It is really important to understand a nd quantify these weak interactions to be able to designing new supra molecular s ystems. In particular,aro matic inter actions play a vital role in supramo lecularchem istry and biology. Aromatic rings can participate in several noncova ent interactions; C – H/π, cation–π, anion–ʌ, and lp/π.T he density of charge in aromatic rings can be affected by substit uting hydrogen atoms by electron withdrawin g groups, for instance fluorine atoms.The importance of anion–π interactions, i.e., noncovalent forces b etween electron deficient aromatic systems and anions, has been recognized by a great deal of theoretical and exp erimental in vestigations.