A new class of squarylium homologue, namely, an electronically neutral methine-bridged bisquarylium dye, was synthesized by a reaction of 4-(4-N,N-dialkylaminophenyl)-3-hydroxy-3-cyclobutene-1,2-dione with an excess amount of triethyl orthoformate. The X-ray crystallographic analysis revealed that the bisquarylium dye consists of two anilino-substituted cyclobutene components which are bridged with each other by a methine carbon. It was also confirmed that it possesses a highly delocalized π-conjugation structure over the whole molecule. Its unique electronic structure yielded an intense light absorption in the near-infrared region. The complexation properties of the dye with various metal cations were investigated, and the complexation with transition metal cations such as Cr 3 + , Mn 2 + , Fe 2 + , Co 2 + and Cu 2 + exclusively induced drastic absorption spectral changes with hypsochromic shifts (Δλ; 59-197 nm).