Electronic structure and optical properties of a tin‐encapsulated nickel porphyrazine compound

The recently synthesized metal‐encapsulated porphyrazine compound, [Sn(t‐Bu)₂]₄‐star‐Ni(porphyrazine)‐S₈, shows very interesting structural and optical absorption features compared with other metal‐centered porphyrazines, e.g., metal phthalocyanines (Pc). Using self‐consistent‐field local density theory, we studied the ground‐state and excited‐state electronic structure of this molecule and compared it with its metal phthalocyanine analog NiPc. The theoretical optical spectra including oscillator strengths are in good agreement with experimental absorption and show that the characteristic transitions at the so‐called Soret band in NiPc are red‐shifted in the new compound. © 1994 John Wiley & Sons, Inc.