Two belt-like expanded carbaporphyrins (NB1 and NB2) were prepared via a one-pot procedure that involves a [6 + 3] condensation between a pyrene-bearing tetrapyrrole precursor (2) and pentafluorobenzaldehyde, followed by oxidation. Single crystal X-ray diffraction analyses revealed that NB1 and NB2 both contain six dipyrromethene moieties and three bridging pyrene units. In the structure of NB1, there are two vertically orientated pyrene units and one transverse orientated pyrene unit; however, in NB2 all three pyrene units are vertically orientated. The structural differences between NB1 and NB2 are reflected in their respective physical properties as revealed by proton NMR, UV-vis, and fluorescence spectroscopies. In contrast to all-carbon nanobelts, NB1 and NB2 contain multiple pyrrolic nitrogen donors that could serve as potential metal coordination sites. As a test of this possibility, NB2 was used to prepare an unprecedented Zn complex containing 7 Zn2+ metal centers connected by a network of bridging atoms, as confirmed by a single crystal X-ray diffraction analysis. To the best of our knowledge, this is the first example of a belt-like molecular system that can coordinate multiple metal ions both along the backbone and within its central cavity.
Bibliographical noteFunding Information:
The work in Austin was supported initially by the National Science Foundation (CHE-1807152 to J.L.S.) with subsequent funding provided by the Robert A. Welch Foundation (F-0018 to J.L.S.). The work at Beijing Normal University (BNU) was supported by the startup funding (Grant 312232114 to X.-S. K.). The work at Yonsei University was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea Government (MSIT) (No. 2020R1A5A1019141). The quantum mechanical calculations were performed with the supercomputing resources of the Korea Institute of Science and Technology Information.
© 2022 American Chemical Society. All rights reserved.
All Science Journal Classification (ASJC) codes
- Colloid and Surface Chemistry