Tri-fluoro-methane-sulfonate salt of 5,10,15,20-tetra-kis-(1-benzyl-pyridin-1-ium-4-yl)-21 H ,23 H -porphyrin and its Ca II complex.

The synthesis, crystallization and characterization of a tri-fluoro-methane-sulfonate salt of 5,10,15,20-tetra-kis-(1-benzyl-pyridin-1-ium-4-yl)-21 H ,23 H -por-phy-rin, C 68 H 54 N 8 4+ ·4CF 3 SO 3 - ·4H 2 O, 1 ·OTf, are reported in this work. The reaction between 5,10,15,20-tetra-kis-(pyridin-4-yl)-21 H ,23 H -porphyrin and benzyl bromide in the presence of 0.1 equiv. of Ca(OH) 2 in CH 3 CN under reflux with an N 2 atmosphere and subsequent treatment with silver tri-fluoro-methane-sulfonate (AgOTf) salt produced a red-brown solution. This reaction mixture was filtered and the solvent was allowed to evaporate at room temperature for 3 d to give 1 ·OTf. Crystal structure determination by single-crystal X-ray diffraction (SCXD) revealed that 1 ·OTf crystallizes in the space group P 2 1 / c . The asymmetric unit contains half a porphyrin mol-ecule, two tri-fluoro-methane-sulfonate anions and two water mol-ecules of crystallization. The macrocycle of tetra-pyrrole moieties is planar and unexpectedly it has coordinated Ca II ions in occupational disorder. This Ca II ion has only 10% occupancy (C 72 H 61.80 Ca 0.10 F 12 N 8 O 16 S 4 ). The pyridinium rings bonded to methyl-ene groups from porphyrin are located in two different arrangements in almost orthogonal positions between the plane formed by the porphyrin and the pyridinium rings. The crystal structure features cation⋯π inter-actions between the Ca II atom and the π-system of the phenyl ring of neighboring mol-ecules. Both tri-fluoro-methane-sulfonate anions are found at the periphery of 1 , forming hydrogen bonds with water mol-ecules.