Design, synthesis, and properties of phthalocyanine complexes with main-group elements showing main absorption and fluorescence beyond 1000 nm.

We present a comprehensive description of the unique properties of newly developed phthalocyanines (Pcs) containing main-group elements that absorb and emit in the near-IR region. Group 16 (S, Se, and Te) elements and group 15 (P, As, and Sb) elements were used as peripheral and central (core) substituents. With the introduction of group 16 elements into free-base Pc, a red-shift of the Q-band was observed, as a result of the electron-donating ability of group 16 elements particularly at the α positions.

Rationally designed phthalocyanines having their main absorption band beyond 1000 nm.

Highly air-stable phthalocyanines (Pcs) having their main absorption band beyond 1000 nm have been synthesized using main-group elements as peripheral and central (core) substituents. The resultant [(PhS)(8)PcP(OMe)(2)][PF(6)] and [(PhSe)(8)PcP(OMe)(2)][PF(6)] show a single Q-band peak at 1018 and 1033 nm, respectively, which was achieved by carefully taking into account the spectroscopic properties of Pcs and the characteristics of the frontier orbitals. The large red shift can be considered to originate from synergistic effects involving both the group-15 and -16 elements.

A new method to prepare multicellular spheroids in cancer cell lines using a thermo-reversible gelation polymer.

The purpose of this study is to utilize the thermo-reversible gelation polymer in which the sol-gel transitting phase is reversibly changed by temperature in a three-dimensional culture system. Human cancer cells have been observed to form multicellular spheroids, whereas fibroblasts slowly develop into small spheroids with the culture medium including this polymer. This polymer has some advantages for use as a culture material, as follows: first, cancer cells grow three-dimensionally in the aqueous solution of this polymer; second, it is easy to harvest cells or spheroids in the aqueous solution of this polymer by simply cooling down the temperature; and third, the culture medium including this polymer is so translucent that the cells or spheroids can be observed through a phase-contrast microscope.