Preparation, characterization, and structural analysis of d⁸ palladium and platinum compounds containing amino acid ester derivatized diimine ligands. Observation of liquid crystal behavior

Abstract

Eight new compounds, M(pyca(CH₂)_xCOOR)Cl₂, M = Pd, Pt; R = Me, Et; x = 2, 3, 5, 11, were prepared. The resulting new complexes were characterized by ¹H and ¹³C NMR spectroscopy and each was also structurally elucidated by X-ray crystallography. The compounds share general structural features, but there are differences in the alignment of the alkyl chain; as the chain lengthens, the chain straightens relative to the plane of the metal complex. For the dodecanoic ester derivatives, a nearly linear alkyl chain was observed. These longer alkyl derivatives show mesogenic behavior.

Keywords:

• Amino acid
• crystal structure
• diimine
• palladium
• platinum