Metastable Lanthanide Complex Formation and their Thermal Behavior in the Solid State with Alkylcyanobiphenyls

ABSTRACT

The formation of two metastable complexes (M/L = 1/2 and 1/1) is shown for low temperature co-condensates of europium and samarium vapors with mesogenic ligand 4-penthyl-4′-cyanobiphenyl (5CB). The DFT-calculations based on hybrid B3LYP potential have been carried out to study the equilibrium structures of complexes. The model structures including one and two metal atoms with antiparallel disposition of ligand molecules are considered. The spectral shifts for ligand CN-group stretching vibrations and the relative thermal stability of the complexes are discussed.

Keywords:

• cryosynthesis
• lanthanides
• low temperature
• metal-mesogens

Acknowledgments

The work was supported by RFBR grants 04-03-32748 and INTAS grant 2000-00911.

Notes

ϕ_1, – the torsion angle between benzene ring planes of the same ligand

ϕ_2, – the angle between benzene ring planes of different ligands

ϕ_3, – the angle between the axis of the ligands