Clamshell‐type Bis‐phthalocyanine with Tetrachlorocyclotriphosphazene Intramolecular Bridge: Synthesis and Structural Evaluation by DFT, NMR and Optical Spectroscopy.

An interaction of 2‐hydroxy‐9(10),16(17),23(24)‐tri‐tert‐butyl‐29H,31H‐ phthalocyanine (1) with hexachlorocyclotriphosphazene (phosphonitrilic chloride trimer) produced, along with the A3B type low‐symmetry monophthalocyanine (monomer 2), a bis‐derivative 3 with spectral characteristics such as that of most clamshell‐type phthalocyanines (typically, H‐dimers). The reaction can be considered conditionally selective. DFT calculations showed the possibility of the existence of several isomers. Based on the UV‐Vis, fluorescent and NMR studies, we found that 3 was obtained as an inseparable mixture of three diastereomers‐achiral cis‐isomer and two chiral trans‐isomers. DFT analysis has also shown that cis‐isomer can exist as two rotamers‐parallel and oblique, by an analogy with the cofacial J‐type dimers that we obtained earlier. [ABSTRACT FROM AUTHOR]