Tri(3‐pyridyl)‐ and Tri(4‐pyridyl)phosphine Chalcogenides and Their Complexes with ZnTPP (TPP = Tetraphenylporphyrinate)

The preparation, spectroscopic characterization (NMR and IR spectroscopy), and solid‐state structures of tri(3‐pyridyl)‐ and tri(4‐pyridyl)phosphine chalcogenides (E = O, S, Se) as well as their ability to behave as ligands for ZnTPP (TPP = tetraphenylporphyrinate) moieties are reported. In the solid state, the compounds from this family are three‐bladed molecular propellers that crystallize as racemates. Both triorganophosphine sulfides and selenides, (3‐Py) 3 PE [Py = pyridyl, NC 5 H 4 ; E = S ( 2 ), Se ( 3 )] and (4‐Py) 3 PE [E = S ( 6 ), Se ( 7 )], quantitatively form complexes with ZnTPP by selective coordination of all three pyridyl groups of a molecular unit to three metalloporphyrin moieties. The formation of these complexes in chlorinated solvents is unambiguously proven by spectroscopic methods (i.e., multinuclear NMR and UV/Vis spectroscopy). The affinity of these ligands towards ZnTPP is different in benzene, yielding a mixture of products in solution.