A Spin-Active, Electrochromic, Solvent-Free Molecular Liquid Based on Double-Decker Lutetium Phthalocyanine Bearing Long Branched Alkyl Chains.

Synthesis and characterization of a novel, multifunctional, solvent-free room-temperature liquid based on alkylated double-decker lutetium(III) phthalocyanine (Pc2 Lu) are described. Lowering of the melting point and viscosity of intrinsically solid Pc2 Lu compounds has been achieved through the attachment of flexible, bulky, and long branched-alkyl chains, that is, thio-2-octyldodecyl, to the periphery of the Pc2 Lu unit. The embedded Pc2 Lu unit maintains its inherent molecular functions, such as spin-active nature and electrochromic behavior in the liquid state. Comparison of the properties with a solid-like Pc2 Lu derivative, functionalized with shorter alkyl chains, that is, thio-2-ethylhexyl, underlines the importance of the hampering effect on the π-π interactions of neighboring Pc2 Lu molecules by bulkier and longer branched-alkyl chains. This study could possibly pave the way for novel multifunctional liquids whose spin-activities are associated with their rheological or optoelectronic properties.