In view of multi-porphyrin arrays and new porphyrinoids, whih has potential applications in optoelectronic devices, sensors, photovoltaic devices, non-linear optical(NLO) materials, photodynamic therapy (PDT) pigments, light-harvesting models, and host-guest chemistry. Both the manipulation of interporphyrinic interaction and design of new structural porphyrinods are often essential to achieve desirable electronic and photophysical properties. Recently, the Osuka group developed a transition metal-catalyzed coupling reaction that has been proven to be very useful to construct multiporphyrinic systems. Till now we have adopted this strategy and prepared many heterocycles bridged β-to-β porphyrin arrays, including direct-bridged β-to-β porphyrin nanorings^[1], earring porphyrins^[3]. The experiment results indicated that the building blocks will remarkably affect the target molecules. As the bridge is thienylene, the main products is cyclic dimer, trimer, when the bridge is pyridylene, there are trace cyclic products are obtained. when the bridge is free base or Zn(II) porphyrin, bigger loop are formed, while Ni(II)porphyrin is used, the products is much simple. As to synthesis of porphyrin nanobarrel, if the porphyrin monomer is free base or Zn(II) porphyrin, no porphyrin barrel is obtained, which means that only ruffled Ni(II)porphyrin monomers can be used to synthesis porphyrin barrels. Synthesis of direct linked porphyrin nanorings is affected by the meso-substituent on porphyrin, when the substituent is aryl, only trimer and twinned pentamer can be prepared, when the substituent is alkyl, tetramer and twinned heptamer can be obtained.The photophysical study revealed that these porphyrin arrays and porphyrinoids exhibit either longer fluorescent lifetime, larger two photon absorption values or Near-infrared absorptions. Some new porphyrin arrays or porphyrinnoids recently have been constructed through Pd-catalyzed cross-coupling reactions (Figure 1), further study on their properties is underway in our lab.

Figure 1. Crystals of earring porphyrins and multi-porphyrin arrays

References

1. H. Cai, K. Fujimoto, J. M. Lim, C. Wang, W. Huang, Y. Rao, S. Zhang, H. Shi, B. Yin, B. Chen, M. Ma, J. Song, D. Kim, and A. Osuka, Angew. Chem. Int. Ed., 2014, 51, 11088-11091.

2. H. Huang, S.-K. Lee, Y. M. Sung, F. Peng, B. Yin, M. Ma, B. Chen, S. Liu, S. R. Kirk, D. Kim, and J. Song, Chem. Eur. J., 2015, 21, 15328-15338.

3. Y. Rao, T. Kim, K. H. Park, F. Peng, L. Liu, Y. Liu, B. Wen, S. Liu, S. R. Kirk, L. Wu, B. Chen, M. Ma, M. Zhou, B. Yin, Y. Zhang, D. Kim, and J. Song, Angew. Chem. Int. Ed. 2016, 55, 6438-6442