The synthesis and spectral investigation of a novel highly water-soluble, aggregation-free antimony(V)-phthalocyanine absorbing light in optical therapeutical window

A novel antimony–phthalocyanine, [Sb(H3tsppc)(OH)2], where H3tsppc denotes monodeprotonated tetrakis{(2′,6′-dimethyl-4′-sulfonic acid)phenoxyl}phthalocyaninate, has been synthesized through sulfonation of [Sb(tppc)(OH)2]+ (tppc denotes tetrakis{(2',6'-dimethyl)phenoxyl}phthalocyaninate) in concentrated sulfuric acid. This compound is highly soluble in water (ca. 4 × 10− 2 M) without surfactant or alcohol. Moreover, it has been found free from aggregation in water up to almost 10− 4 M, unlike its copper and metal-free analogues, and show an intense optical absorption and emission band in optical therapeutical window (700–800 nm). The axial hydroxyl groups play a crucial role in disaggregation of the antimony derivative in water.

Graphical abstractA highly water-soluble antimony–phthalocyanine, unlike its copper and metal-free analogues, has been found aggregation-free in water without surfactant or alcohol, on the basis of optical absorption and emission spectroscopy.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The synthesis of highly water-soluble antimony(V)-phthalocyanines is reported. ► Spectral properties of the new antimony complex is reported. ► Aggregation-free characteristics of the new compound in water are studied.