THE QM/MM DESIGN OF PRECURSORS FOR CVD AND ALD PROCESSES

摘要

In this work, a new theoretical approach to design lanthanide coordination compounds as potential precursors for the CVD technique is proposed. The structures and properties of lanthanum and lutetium P-diketonate-based mixed ligand complexes with o-phenanthroline, [Ln(dik)_3phen], are studied by using the combined quantum mechanical/molecular mechanical (QM/MM) technique with the universal force field for the MM part. The Ln(dik)_3 - phen bond energies are estimated in the single-point calculations within B3PW91 density functional theory. It is shown that the Ln(dik)_3 -phen bond energies decrease in the series from non-bulky β-diketonate ligands to their branched analogues. The introduction of the fluorinated substituents leads to the substantial increase in bond energy. The Natural Bond Orbital analysis is used to characterize the electronic structure of complexes.