Preliminary study of [Ni(en)3] (CF3CO2)2 and Ni(en) (hfpd)2 as precursors for metalorganic chemical vapour deposition: structural properties and thermal behaviours (en = ethylenediamine, hfpd = hexafluoropentadionato(−))

Abstract

[Ni(en)3](CF3CO2)2 (1) and Ni(en)(hfpd)2 (2) were both obtained by working in the system Ni2+/ethylenediamine/hexafluoropentanedione. They have been comparatively studied as possible sources for chemical vapour deposition. Both crystal structures have been determined from single-crystal X-ray diffraction: compound 1 is triclinic, space group P1̄, a = 9.335(1), b = 12.793(4), c = 8.512(2) Å, α = 84.28(2), β = 109.80(1), γ = 104.25(2)°, and has an ionic structure; compound 2 is monoclinic, space group P2t/c, a = 10.863(8), b = 15.833(6), c = 11.096(9) Å, β = 99.27(4)°, and is a neutral complex. Thermal gravimetric analyses have shown that compound 2 could be sublimed under one atmosphere whereas compound 1 could not. Preliminary chemical vapour deposition experiments were carried out under vacuum. Compound 1 gave a coating of Ni3C in the range 260–310°C whereas compound 2 gave no coating up to a substrate temperature of 350°C.