Photodegradation of rhodamine-B and methyl orange employing nano-alumina developed from new aluminium(III) complex(es) associated with phenanthridine-salicylaldehyde derived ligands

Abstract

A series of five new heteroleptic mononuclear derivatives of aluminium(III) have been synthesized and characterized. Complexes [(CH3COCH2COCH3)2Al(1a)] 2a, [(CH3COCH2COCH3)2Al(1b)] 2b, [(CH3COCH2COCH3)2Al(1c)] 2c, [(CH3COCH2COCH3)2Al(1d)] 2d and [(CH3COCH2COCH3)2Al(1e)] 2e were obtained by treating Al(OPr i )3 with acetylacetone and bidentate ligands (developed by treating phenanthridine and salicylaldehyde) 1a–1e (1a = C27H21NO; 1b = C28H23NO2; 1c = C34H33NO4; 1d = C27H20BrNO; 1e = C27H20N2O3) in 1:2:1 stoichiometry using anhydrous benzene as solvent. All the newly synthesized aluminium(III) complexes were characterized by NMR (1H and 13C), FTIR, HPLC, HRMS and elemental analysis. Derivatives 2a-2e were confirmed by dept-135 and HSQC also. Complex 2a was employed as precursor for the synthesis of active alumina by well-established sol-gel technique. Nanostructured alumina was confirmed by powder XRD, FTIR, TGA-DTA and BET surface area, Fe-SEM and TEM analyses. Alumina synthesized from 2a was used for photodegradation of rhodamine-B and methyl orange dyes that resulted in remarkably high (>93%) decolorization within 140 minutes exposure of natural sunlight.