Two spectral QSPR models of porphyrin macromolecules for chelating heavy metals and different ligands released from industrial solvents: CH2Cl2, CHCl3 and toluene

ABSTRACT

Two simple and reliable correlations are introduced for the prediction of emission and absorption of porphyrins and their derivatives, i.e. metalloporphyrins and ligand coordinated metalloporphyrins. They can be used to sense the extracted precious metals. The proposed models require only simple structural parameters such as the number of carbon, metal and metal-free molecular fragments of desirable porphyrins or their derivatives. Since the proposed models depend on molecular structures of the desired compounds, they can be easily applied for complex molecular structures. Experimental data of 272 porphyrin derivatives were used to derive and test the novel models for the assessment of their emission (Em.) and absorption (Abs.) values in three solvents namely dichloromethane, toluene and chloroform. The values of the coefficients of determination (r ²) for the training set (183 compounds) in dichloromethane and three different test sets, corresponding to the three mentioned solvents, for the emission and absorption correlations were greater than 0.70. The calculated values of the root-mean-square error (RMSE) for the training sets of Em. and Abs. correlations were equal to 7.56 and 4.86 nm, respectively. Further statistical parameters also confirm the high reliability of the new models.