Synthesis of antipodal β-trisubstituted meso-tetraphenylporphyrins and the crystal structure of hexaphenylporphinatozinc(II) bispyridinate complex

Abstract

A series of antipodal β-trisubstituted meso-tetraphenylporphyrins, H 2 TPP(R) 3 (R = CH 3 , Ph, PE, and 2 ′-thienyl) derivatives and their metal (Cu(II) and Zn(II)) complexes were synthesised and characterised by electronic absorption, 1 H NMR spectroscopy and mass spectrometry. The magnitude of the red-shift in absorption bands in these free-base porphyrins depend on the nature of the substituent and follow the general trend: PE > 2 ′-thienyl > Br > Ph > CH 3. Synthesis, characterisation and crystal structure of 2,5,10,12,15,20hexaphenylporphinato zinc(II) bispyridinate, ZnTPP(Ph) 2 (Py) 2 complex is also reported. It shows planar geometry of the porphyrin ring with two β-phenyls located at the antipodal 2,12-pyrrole positions. The two axially coordinated pyridine ring planes are oriented almost parallel to each other and they are in staggered conformation relative to opposite pyrrolic nitrogens. The normal-coordinate structural decomposition analysis of the ZnTPP(Ph) 2 (Py) 2 complex revealed slight wave distortion of the macrocycle.

Superior Sensor for Be2+ Ion Recognition via the Unprecedented Octahedral Crystal Structure of a One-Dimensional Coordination Polymer of Crown Fused Zinc Phthalocyanine

“…Although there exist some ZnPs with an octahedral configuration obtained by the coordination of solvent molecules such as 1,4-dioxane and pyridine (Py) from axial positions, only one example of ZnPc with an octahedral configuration coordinated with two acetone molecules is known in the literature . However, ZnPc single crystals obtained so far possess either a square or square-pyramidal geometry. ,,− Another interesting property of the crystal structure of P-CfZnPc is that, although the H 2 O oxygen–zinc bond in [ZnPc­(H 2 O)]·2DMF and DMF oxygen–zinc bond in [ZnPp­(DMF)]·DMF have average distances of 2.08 and 2.10 Å, respectively, P-CfZnPc prefers a longer (2.63 Å) crown ether oxygen coordination.…”

“…Although there exist some ZnPs with an octahedral configuration obtained by the coordination of solvent molecules such as 1,4-dioxane 62 and pyridine (Py) 63 from axial positions, only one example of ZnPc with an octahedral configuration coordinated with two acetone molecules is known in the literature. 54 However, ZnPc single crystals obtained so far possess either a square or square-pyramidal geometry.…”