Comparison Between Two Kinds of Connectivity Indices for Measuring the π-Electronic Energies of Benzenoid Hydrocarbons

In this paper, we show that both the general product-connectivity index χ α and the general sum-connectivity index <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" display="inline"> <m:mmultiscripts> <m:mi>χ</m:mi> <m:mi>α</m:mi> <m:none/> <m:mprescripts/> <m:none/> <m:mi>s</m:mi> </m:mmultiscripts> </m:math> \({}ˢ{χα}\) are closely related molecular descriptors when the real number α is in some interval. By comparing these two kinds of indices, we show that the sum-connectivity index <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" display="inline"> <m:mmultiscripts> <m:mi>χ</m:mi> <m:mrow> <m:mo>−</m:mo> <m:mn>0.5601</m:mn> </m:mrow> <m:none/> <m:mprescripts/> <m:none/> <m:mi>s</m:mi> </m:mmultiscripts> </m:math> \({}ˢ{χ-0.5601}\) is the best one for measuring the π -electronic energies of lower benzenoid hydrocarbons. These improve the earlier results.