1. Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India, Chemical Laboratory, Central Leather Research Institute, Adyar, Chennai 600 020, India, School of Chemistry, Department of Physics, L. N. Government College, Ponneri 601 204, India, Bharathidasan University, Tiruchirappalli-620 024, India, and Laboratorio de Química Teórica Computacional (QTC), Facultad de Química, Pontificia Universidad Católica de Chile, Casilla 306, Correo 22, Santiago, Chile