title: Synthesis and characterisation of cyclopentadienyl complexes of barium: precursors for atomic layer deposition of BaTiO3.
abstract: Cyclopentadienyl complexes Ba(C5Me5)2(THF)2 (1), Ba(C5Me5)2(A) (A = THF, dien, trien, diglyme, triglyme) (2-5), Ba(Pr(i)3C5H2)2(THF)2 (6), Ba(Bu(t)3C5H2)2(THF) (7), Ba(Me2NC2H4C5Me4)2 (8) and Ba(EtOC2H4C5Me4)2 (9) were prepared and characterised with TGA/SDTA, NMR and MS. Crystal structures of 2, 4, 5, 7, 8 and 9 are presented. All complexes prepared sublime under reduced pressure and complexes 1, 6 and 7 showed volatility also under atmospheric pressure. Complexes 1, 6 and 7 lose the coordinated THF when evaporated while complexes 2-5 are sublimable as complete molecules under reduced pressure. Complexes with bulky cyclopentadienyl ligands (6 and 7) are the most thermally stable and volatile among the prepared barocenes. X-ray structure determinations reveal that all the complexes studied are monomeric. Complexes 1, 7 and 8 were successfully tested in BaTiO3 thin film depositions by atomic layer deposition (ALD).
authors.affiliation: Laboratory of Inorganic Chemistry, Department of Chemistry, University of Helsinki, P.O.Box 55, Helsinki, FIN-00014, Finland. timo.hatanpaa@helsinki.fi
authors.forename: Timo
authors.initials: T
authors.lastname: Hatanpää
authors.forename: Marko
authors.initials: M
authors.lastname: Vehkamäki
authors.forename: Ilpo
authors.initials: I
authors.lastname: Mutikainen
authors.forename: Jarno
authors.initials: J
authors.lastname: Kansikas
authors.forename: Mikko
authors.initials: M
authors.lastname: Ritala
authors.forename: Markku
authors.initials: M
authors.lastname: Leskelä