The novel selenoviologen-based tetracationic cyclophanes (green boxes3and5) with rigid electron-deficient cavities are synthesized via SN2 reactions in two steps. The green boxes exhibit good redox properties, narrow energy gaps, and strong absorption in the visible range (370–470 nm), especially for the green box5containing two selenoviologen (SeV2+) units. Meanwhile, the femtosecond transient absorption (fs-TA) reveals that the green boxes have a stabilized dicationic biradical, high efficiency of intramolecular charge transfer (ICT), and long-lived charge separation state due to the formation of cyclophane structure. Based on the excellent photophysical and redox properties, the green boxes are applied to electrochromic devices (ECDs) and visible-light-driven hydrogen production with a high H2generation rate (34 μmol/h), turnover number (203), and apparent quantum yield (5.33 × 10–2). In addition, the host–guest recognitions are demonstrated between the green boxes and electron-rich guests (e.g.,G1:1-naphthol andG2:platinum(II)-tethered naphthalene) in MeCN through C–H···π and π···π interactions. As a one-component system, the host–guest complexes ofgreen box⊃G2are successfully applied to visible-light photocatalytic hydrogen production due to the intramolecular electron transfer (IET) between platinum(II) ofG2and SeV2+of the green box, which provides a simplified system for solar energy conversion.

原文链接：https://pubs.acs.org/doi/full/10.1021/jacs.3c00800