Heterobimetallic 3d-4f (Zn/La) {6,6′-dimethoxy-2,2′- [naphthalene-2,3-diylbis(nitrilomethylidyne)] diphenolato}-pyridylzinc(II)-tris(nitrato-O,O′) lanthanum(III) monohydrate

Abstract

Herein, we report the synthesis and structural characterization of a complex with extended aromaticity based on a naphthalene-bridged Schiff base complex with two metal binding pockets. In a first step, the Zn(II) complex (ZnL), {6,6′-dimethoxy-2,2′-[naphthalene-2,3- diylbis(nitrilomethylidyne)]diphenolato}a-pyridylzinc(II) was isolated followed by refluxing with lanthanum(III) nitrate to produce the heterobimetallic complex {ZnL[La(NO3)3·H2O]}. Crystals suitable for X-ray diffraction were grown by vapor diffusion of THF into a pyridine solution of the complex. The monoclinic unit cell (P21/n) is commensurately modulated along the c-axis direction and contains four crystallographically independent molecules with pseudo-translational symmetry being broken by slightly differing orientations of included pyridine and THF solvate molecules. The zinc atom adopts a distorted square pyramidal geometry and sits slightly above the ligand plane, whereas the lanthanum atom adopts an all-face capped trigonal prismatic geometry and sits below the ligand plane. Structural characterization of this diamagnetic complex lays the groundwork for applying these synthetic techniques to the near-infrared emitting lanthanides for practical application.