Variations on Nickel Complexes of the vic-Dioximes:  An Understanding of Factors Affecting Volatility toward Improved Precursors for Metal−Organic Chemical Vapor Deposition of Nickel

Abstract

The vic-dioxime complexes bis(2,3-butanedionedioximato)nickel(II), Ni(dmg) 2 ; bis(3,4hexanedionedioximato)nickel(II), Ni(deg) 2 ; bis(4,5-octanedionedioximato)nickel(II), Ni(dpg) 2 ; bis(ethanedialdioximato)nickel(II), Ni(g) 2 ; bis(1,2-diphenylethanedionedioximato)nickel(II), Ni(dbg) 2 ; bis(1,2-cyclohexanedionedioximato)nickel(II), Ni(nox) 2 ; and bis(2,3-pentanedionedioximato)nickel(II), Ni(meg) 2 , were prepared. Their volatilities were compared under ambient and reduced pressure using thermogravimetry. Ni(deg) 2 and Ni(dpg) 2 were the most volatile, and the variation in volatility of each complex was explained on the basis of ligand effects, crystal packing, and nickel-nickel distances using solid-state electronic spectra. The crystal structure of Ni(dpg) 2 was determined for the first time: monoclinic crystal system, C2/c space group. The complex packs in pairs related by the c-glide plane symmetry. Short intrapair distances of 3.312(2) Å are observed between Ni and N with short and long Ni-Ni distances of 3.2044(5) and 5.7964(5) Å, respectively. Metal-organic chemical vapor deposition (MOCVD) experiments were conducted using Ni(deg) 2 as precursor in a vertical cold-walled reactor. The precursor transport and film growth behavior, morphology, and composition have been examined. Pure films could be grown between 350 and 400 °C in helium. Growth rates were greater with additional hydrogen, but the films were heavily contaminated with carbon. The difference in growth rates and film morphology for the different reactor conditions was investigated.

Synthesis of New Glyoxime Derivatives, Characterization and Investigation of Their Complexes with Co(II), Ni(II), and Cu(II) Metals and Thermal Studies

“…The electronic spectra of the nickel(II) and copper(II) complexes show absorption bands around 672-689 and 623-637 nm attributed to 1 A 1g 1 B 1g for Ni(II) and 2 T 2g 2 E g (G) for Cu(II) transition, which is compatible with these complexes having a square planar structures. The electronic spectra of the nickel(II) and copper(II) complexes show an absorption band around 395-406 nm attributed to the L M (charge transfer) transition [31,32]. Magnetic susceptibility measurements provide sufficient data to characterize the structure of the complexes ( Table 3).…”

Preparation and characterization of Co(II), Ni(II) and Cu(II) complexes of a ligand containing 1,3,4-thiadiazole groups

“…spectra data of the complexes in the solid state are listed in Table 3. The electronic spectra of the Co(II), Ni(II) and Cu(II) complexes show absorption bands at 595, 670 and 360 nm, respectively, which may be assigned to 4 A 2g (F) ‹ 4 T 1g (F) for Co(II), 3 T 1g (F) ‹ 3 A 2g for Ni(II) and 2 T 2g ‹ 2 E g for Cu(II) transition [20][21][22][27][28][29][30]. The peaks belonging to the p fi p* transitions are shifted to a longer wavelength as a consequence of coordination when binding with metal, confirming the formation of metal complexes.…”

Synthesis, crystal structures and thermal behavior of Ni(pda)(hfac)2 and Ni(pda)(thd)2 as potential MOCVD precursors (pda-1,3-diaminopropane, hfac-1,1,1,5,5,5-hexafluoro-2,4-pentanedionato(-), thd-2,2,6,6-tetrametyl-3,5-heptanedionato(-))

“…Ni(h 5 -C 5 H 5 ) 2 complex and its derivatives have C, Cecoordination as well [9,10]. There are also nickel chelates with N, Necoordination, for example Ni(dmg) 2 (bis(2,3-butanedionedioximato)nickel(II), Ni(deg) 2 (bis(3,4-hexanedionedioximato)nickel(II)), Ni(dpg) 2 , bis(ethanedialdioximato)nickel(II)) [11,12]. The most known complexes with O, Oecoordination are nickel (II) b-diketonates: Ni(acac) 2 [13], Ni(thd) 2 [14] and Ni(hfac) 2 [15].…”