Crystal and molecular structure of the silver(II) and zinc(II) derivatives of meso-tetraphenylporphyrin. An exploration of crystal-packing effects on bond distance

The crystal and molecular structures of four-coordinate silver(I1) and zinc(I1) tetraphenylporphyrinates have been determined. Both complexes crystallize in the triclinic system and are isomorphous with the triclinic modification of the parent macrocycle H2TPP. Bond distances in the centrosymmetric coordination groups of both complexes are found to be statistically nonequivalent. Features of the crystal packing of the compounds suggest that this inequivalence arises from asymmetric lattice packing. The average Ag-N distance is 2.092 A (individual values 2.082 (3) and 2.101 (3) A), and that for Zn-N is 2.037 A (individual values 2.045 (2) and 2.029 (2) A). Crystal data for AgTPP: triclinic, a = 10.503 (2) A, b = 12.485 (2) A, c = 6.351 (2) A, a = 97.72 (l)', P = 100.68 (l)', y = 97.150 (9)', 2 = 1, space group Pi, 5616 observed data, R, = 0.059. Crystal data for ZnTPP: triclinic, a = 10.382 (1) A, b = 12.421 (2) A, c = 6.443 (1) A. 01 = 98.30 (I) ' , P = 101.15 (l)', y = 96.47 (I) ' , 2 = 1, space group Pi, 3729 observed data, R, = 0.036.