A sandwich-type tetrakis(phthalocyaninato) europium–cadmium quadruple-decker complex: structural, spectroscopic, OFET, and gas sensing properties

Abstract

A new tetrakis(phthalocyaninato) europium(III)–cadmium(II) quadruple-decker complex {[Pc(SC₆H₁₃)₈]Eu[Pc(SC₆H₁₃)₈]Cd[Pc(SC₆H₁₃)₈]Eu[Pc(SC₆H₁₃)₈]} (1) has been designed, synthesized, and characterized. Electrochemical measurement reveals the location of its HOMO and LUMO energy levels in the ranges that are necessary for organic ambipolar semiconductors. Furthermore, both the OFET and gas sensing properties were studied on the self-assembled film of the quadruple-decker fabricated by a solution processable Quasi–Langmuir–Shäfer (QLS) method. Ambipolar OFET properties are revealed with carrier mobilities of 5.6 × 10⁻³ and 1.2 × 10⁻³ cm² V⁻¹ s⁻¹ for the holes and electrons, respectively. Meanwhile, an effective response to NO₂ in the concentration range from 0.25 to 2.5 ppm was obtained, which indicates the potential application of the quadruple-decker phthalocyanine complex in organic semiconductors.