Synthesis of novel volatile niobium precursors containing carboxamide for Nb2O5 thin films

摘要

A series of novel Nb(V) tBu-imido/N-alkoxy carboxamide complexes, NbCl2((NBu)-Bu-t)(pyridine)(edpa) (1), NbCl2((NBu)-Bu-t)(pyridine)(mdpa) (2), and Nb((NBu)-Bu-t)(mdpa)(3) (3), were successfully synthesized by metathesis reaction between Nb((NBu)-Bu-t)Cl-3(py)(2) and several equivalents of Na(edpa) (edpaH = Nethoxy-2,2-dimethylpropanamide) and Na(mdpa) (mdpaH = N-methoxy-2,2-dimethylpropanamide). These complexes could potentially serve as precursors for Nb-containing thin films. Compounds 1-3 were characterized by FT-IR and H-1 and C-13 NMR spectroscopies, elemental analysis, and thermogravimetric analysis (TGA). Single crystal X-ray diffraction analysis suggested that complex 3 has a distorted pentagonal bipyramidal geometry around the central Nb atom, with three bidentate mdpa ligands and one tBu imido group saturating the coordination. TGA analysis revealed that the thermal characteristics of 3 were superior to those of 1 and 2. All prepared complexes were able to be distilled or sublimed and expected potential precursors for the fabrication of thin films. (C) 2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).