Syntheses and Characterization of Organoimido Complexes of Niobium(V); Potential CVD Precursors

Abstract

New niobium imido complexes (RN)Nb(NEt2)3 (R = Prn, Pri and But), potential precursors to grow niobium containing thin films by chemical vapor deposition (CVD), were prepared by reacting the corresponding (RN)NbCl3Py2 complexes (R = Prn, Pri and But; py = pyridine) with LiNEt2 in hydrocarbon solvents. The structures of (RN)NbCl3py2 (R = Pri and But), determined by X-ray crystallography, are mononuclear with distorted octahedral geometries. For each complex, three chloride ligands are cis to the imido ligand and occupy meridional positions. One of two py ligands is cis to and the other is trans to the imido ligand. For (PriN)NbCl3py2, the Nb=NPri bond distance (Å) is 1.733(3) and the 〈Nb=N-Pri angle (°) is 178.0(3). Crystal data: monoclinic, space group P21/n, a = 8.805(2), b = 14.930(4), c = 13.407(3) Å, ß = 93.37(2)°, V = 1759.5(7) Å3, Z = 4, DC = 1.565 g cm-3. For (ButN)NbCl3py2, the Nb=NBut bond distance (Å) is 1.734(4)and the ZNb=N-But angle (°) is 174.8(4). Crystal data: monoclinic, space group P21/c, a = 9.609(1), b = 13.591(6), c = 14.615(2) Å, ß = 90.05(1)°, V = 1908.5(9) Å3, Z = 4, Dc = 1.492 g cm -3.