Phthalocyanine (Pc), which has an electron-rich, aromatic structure, exhibits excellent optical properties as well as thermal and chemical stability. Numerous Pc derivatives, based on highly conjugated ring systems, have been proposed to facilitate efficient energy or electron transfer. They have been frequently adopted for suitable applications such as sensors and photosensitizers. In this study, we present the synthesis and properties of various asymmetrical zinc-phthalocyanine (ZnPc) derivatives having a siloxane endgroup linked with alkyl chain spacers of different lengths. A ZnPc-immobilized ITO electrode was prepared by the direct attachment of the siloxane anchoring group to the oxide surface. The synthesized Pcs and the immobilized Pc surfaces were fully characterized by various techniques. The effect of the alkyl spacer length on the optical and electrochemical properties of the Pc-functionalized electrode is briefly discussed.