We report here the preparation (in "one-pot") of a tetra-β″-sulfoleno-meso-aryl-porphyrin in about 80% yield by using an optimized modification of Lindsey's variant of the Adler–Longo approach. The Zn ( II )-, Cu ( II )- and Ni ( II )-complexes of the symmetrical porphyrin were prepared and characterized spectroscopically. Crystal structures of the fluorescent Zn ( II )- and of the non-fluorescent Ni ( II )-tetra-β″-sulfoleno-meso-aryl-porphyrinates showed the highly substituted porphyrin ligands to be nearly perfectly planar. The Zn ( II )-complex of this porphyrin has been used as a thermal precursor of a reactive diene, and — formally — of lateral and diagonal bis-dienes, of a tris-diene and of a tetra-diene, which all underwent [4 + 2]-cycloaddition reactions in situ with a range of dienophiles. Thus, the tetra-β″-sulfoleno-meso-aryl-porphyrin and its metal complexes represent reactive building blocks, "programmed" for the syntheses of symmetrical and highly functionalized porphyrins.
Synthesis, spectroscopic, thermal, and structural properties of cyano-bridged metal complexes containing tetracyanonickelate(II) building blocks with 4-aminomethylpyridine
