Synthesis and structure of Na+ intercalated WO3(4,4'-bipyridyl)0.5

TL;DR

This study reports the synthesis, structural characterization, and Na+ intercalation in WO3(4,4'-bipyridyl)0.5, revealing ordered bipyridyl cages and Na ion distribution within the crystal structure.

Contribution

It provides the first detailed structural analysis of Na+ intercalated WO3(bipyridyl) compounds using single-crystal X-ray diffraction.

Findings

Confirmed the crystal structure with ordered bipyridyl cages.

Na ions are disordered bimodally near cage centers.

Identified the space group as Pbca, correcting previous reports.

Abstract

We have prepared single crystals of WO3(4,4'-bipyridyl)0.5 and doped these by Na-ion implantation. The structure of the resultant NaxWO3(4,4'-bipyridyl)0.5 was determined by single-crystal x-ray diffraction to comprise atomic layers of corner-shared WO5N octahedra linked by the 4,4'-bypyridine via the apical nitrogen. In the observed space group of Pbca, the fully ordered bipyridyl molecules define cage-shaped structures, not the channels erroneously reported previously for the Cmca polymorph. The Na ions are disordered bimodally about the cage centre, displaced in the c-direction so as to lie closer to the apical oxygens.