A Quadruply Bridged Non-Offset Face-to-Face Porphyrin Dimer and Cross-Shaped Pentameric Porphyrin Tapes Based on 2,7,12,17-Tetrakis(pinacolatoboryl) NiII Porphyrin

2,7,12,17-Tetrakis(pinacolatoboryl) Ni^II porphyrin 5 Ni was synthesized in 75 % yield by Ir-catalyzed borylation of porphine followed by Ni^II metalation and has been demonstrated to be a useful synthon, giving 2,7,12,17-tetraaryated Ni^II porphyrins 6 a – d , peripherally octaarylated Ni^II porphyrins 8 a – d , quadruply bridged face-to-face non-offset Ni^II-porphyrin dimer 12 , and cross-shaped β-meso singly linked porphyrin pentamers and nonamers. Oxidation of cross-shaped β-meso singly linked porphyrin pentamers 14 Ni and 14 Zn gave fused pentameric tapes 15 Ni and 15 Zn . The structures of 12 , 14 Zn , and 15 Ni have been revealed by X-ray diffraction analysis. Optical separation of 12 has been accomplished, showing a bisignate coupling pattern for exciton-coupled blue-shifted Soret band. Pentameric porphyrin tape 15 Zn exhibits a red-shifted absorption band at 1156 nm and seven reversible redox waves.