Molecular architecture, characterization, and applications of homoleptic heteronuclear 3d/4f metals’ complexes derived from bi-compartmental Schiff-base

A series of homoleptic heterotrinuclear 3d/4f metal complexes (2-6) of general formula [Zn2Ln(salopn)2(NO3)3H2O].CH3CN.H2O; where Ln = La (2), Nd (3), Sm (4), Gd (5) and Dy (6); have been synthesized by using tetradentate bi-compartmental Schiff base ligand, [2-((E)-(2-((E)-2-hydroxybenzylideneamino)phenylimino)methyl)phenol], and Zn(salopn) precursor (1). The unequivocal evidence of their structural motifs is obtained by characterizing the compounds through FT-IR spectroscopic, and single crystal XRD data, besides the elemental analyses. The trinuclear complex 6 shows that the ligand attached to the metals’ centers, Zn(II) and Dy(III) through N, O and O, O sites respectively. The zinc center is pentacoordinated having distorted square pyramidal geometry and to which Zn-O and Zn-N bond lengths lie in range 2.006-2.035 Å and 2.044-2.060 Å respectively. The dysprosium center is octa-coordinated which is attached to four oxygen atoms from salopn−2 and four oxygens from bidentate nitrate moieties, where Dy-O bond length is in range 2.292-2.517 Å. The photoluminescence (PL) data described that the heteronuclear complexes show characteristic luminescence properties and sensitization across the bi-compartmental ligand. The magnetic parameters for (2-6) are determined and their room temperature χm. T and µeff values are found in range 0.18-15.12 emu.mole−1.K and 1.20-10.96 µB respectively that describe the paramagnetic nature.