Syntheses of phenoxyalkyl esters of 3,3′-bis(indolyl)methanes and studies on their molecular properties from single crystal XRD and DFT techniques

An efficient solvent-free synthesis of phenoxyalkyl esters of bis(indolyl)methanes (BIMs) from indole and formylphenoxyalkyl esters using potassium titanyl oxalate and the molecular properties of these BIMs using DFT method are described here. Structure optimization of BIMs have been carried out using Gaussian program with B3LYP/3-21G(d) basis set. The structures were fully optimized without any geometrical constraints. Coordinates found in crystallographic study were used as input to the Gaussian. The results depict that the geometry of BIMs (3b, 3f, and 3g) are almost same as were observed from crystallography, while the geometry of the substituents are slightly varied.