ic061056i_si_001.cif (146.11 kB)
Guanidinate-Stabilized Monomeric Hafnium Amide Complexes as Promising Precursors for MOCVD of HfO2
dataset
posted on 2006-12-25, 00:00 authored by Andrian Milanov, Raghunandan Bhakta, Arne Baunemann, Hans-Werner Becker, Reji Thomas, Peter Ehrhart, Manuela Winter, Anjana DeviNovel guanidinato complexes of hafnium [Hf{η2-(iPrN)2CNR2}2(NR2)2] (R2 = Et2, 1; Et, Me, 2; Me2, 3), synthesized
by insertion reactions of N,N‘-diisopropylcarbodiimide into the M−N bonds of homologous hafnium amide complexes
1−3 and {[μ2-NC(NMe2)2][NC(NMe2)2]2HfCl}2 (4) using a salt metathesis reaction, are reported. Single-crystal X-ray
diffraction analysis revealed that compounds 1−3 were monomers, while compound 4 was found to be a dimer.
The observed fluxional behavior of compounds 1−3 was studied in detail using variable-temperature and two-dimensional NMR techniques. The thermal characteristics of compounds 1−3 seem promising for HfO2 thin films
by vapor deposition techniques. Metal−organic chemical vapor deposition experiments with compound 2 as the
precursor resulted in smooth, uniform, and stoichiometric HfO2 thin films at relatively low deposition temperatures.
The basic properties of HfO2 thin films were characterized in some detail.