Modulation of transversal conductivity of europium(III) bisphthalocyaninate ultrathin films by peripheral substitution

Highlights: • Phthalocyanine macrocycle substituents control ultrathin film transversal conductivity. • Crown-ether moieties in the complex support transversal charge transfer. • Alkoxylated bisphthalocyanines offer intrinsic insulator properties. -- Abstract: In the present work, we demonstrate that transversal conductivity and, consequently, electrochemical activity of ultrathin solid films of two structurally similar octa-butoxy and tetra-crown-ether substituted europium bisphthalocyaninates are quite different. It is shown that presence of the crown moieties allows excellent transfer of charge through monomolecular ultrathin films of respectively substituted complex. This enables their redox-multistability, which can be utilized in molecular logic and information storage devices. On the other hand, transversal charge transfer is inhibited in the films of octa-butoxy-substituted bisphthalocyaninate, which might be promising for organic field-effect transistor applications.