Through-Space Conjugated Supramolecular Polymer Radicals from Spatial Organization of Cucurbit[8]uril: An Efficient Approach for Electron Transfer and Smart Photochromism Materials

Electron transfer-based long-lived radicals are highly challenging because of the limited control over relative orientation, distance, electronic coupling, and nonradiative recombination channels of the donor and acceptor on a molecular level. Herein, the cavity of macrocyclic cucurbit[8]uril (Q[8]) was found to exhibit excellent advantages in controlling the relative orientation and distance of the donor and acceptor moieties via the spatial organization, i.e., the 4-carboxylphenyl appended viologen-derived guest (BcpV2+) was elegantly rearranged as a rigid linear J-type supramolecular polymer by the Q[8] host via noncovalent interactions. Thus, an unprecedented photoinduced electron transfer (PET) triggered through-space conjugated organic radical with distinct photochromism and a NIR-II photothermal effect was observed. Further studies have indicated that the Q[8] encapsulation-triggered PET cycle exhibited good repeatability without significant loss of its efficiency and had potential application in the fabrication of smart windows and erasable printing under photoirradiation or sunlight. These results suggest that the Q[8] host can be used as a new tool in light-energy conversion and photochromism materials science

Through-Space Conjugated Supramolecular Polymer Radicals from Spatial Organization of Cucurbit[8]uril: An Efficient Approach for Electron Transfer and Smart Photochromism Materials

Electron transfer-based long-lived radicals are highly challenging because of the limited control over relative orientation, distance, electronic coupling, and nonradiative recombination channels of the donor and acceptor on a molecular level. Herein, the cavity of macrocyclic cucurbit[8]uril (Q[8]) was found to exhibit excellent advantages in controlling the relative orientation and distance of the donor and acceptor moieties via the spatial organization, i.e., the 4-carboxylphenyl appended viologen-derived guest (BcpV2+) was elegantly rearranged as a rigid linear J-type supramolecular polymer by the Q[8] host via noncovalent interactions. Thus, an unprecedented photoinduced electron transfer (PET) triggered through-space conjugated organic radical with distinct photochromism and a NIR-II photothermal effect was observed. Further studies have indicated that the Q[8] encapsulation-triggered PET cycle exhibited good repeatability without significant loss of its efficiency and had potential application in the fabrication of smart windows and erasable printing under photoirradiation or sunlight. These results suggest that the Q[8] host can be used as a new tool in light-energy conversion and photochromism materials science

Through-Space Conjugated Supramolecular Polymer Radicals from Spatial Organization of Cucurbit[8]uril: An Efficient Approach for Electron Transfer and Smart Photochromism Materials

Electron transfer-based long-lived radicals are highly challenging because of the limited control over relative orientation, distance, electronic coupling, and nonradiative recombination channels of the donor and acceptor on a molecular level. Herein, the cavity of macrocyclic cucurbit[8]uril (Q[8]) was found to exhibit excellent advantages in controlling the relative orientation and distance of the donor and acceptor moieties via the spatial organization, i.e., the 4-carboxylphenyl appended viologen-derived guest (BcpV2+) was elegantly rearranged as a rigid linear J-type supramolecular polymer by the Q[8] host via noncovalent interactions. Thus, an unprecedented photoinduced electron transfer (PET) triggered through-space conjugated organic radical with distinct photochromism and a NIR-II photothermal effect was observed. Further studies have indicated that the Q[8] encapsulation-triggered PET cycle exhibited good repeatability without significant loss of its efficiency and had potential application in the fabrication of smart windows and erasable printing under photoirradiation or sunlight. These results suggest that the Q[8] host can be used as a new tool in light-energy conversion and photochromism materials science

Through-Space Conjugated Supramolecular Polymer Radicals from Spatial Organization of Cucurbit[8]uril: An Efficient Approach for Electron Transfer and Smart Photochromism Materials

Electron transfer-based long-lived radicals are highly challenging because of the limited control over relative orientation, distance, electronic coupling, and nonradiative recombination channels of the donor and acceptor on a molecular level. Herein, the cavity of macrocyclic cucurbit[8]uril (Q[8]) was found to exhibit excellent advantages in controlling the relative orientation and distance of the donor and acceptor moieties via the spatial organization, i.e., the 4-carboxylphenyl appended viologen-derived guest (BcpV2+) was elegantly rearranged as a rigid linear J-type supramolecular polymer by the Q[8] host via noncovalent interactions. Thus, an unprecedented photoinduced electron transfer (PET) triggered through-space conjugated organic radical with distinct photochromism and a NIR-II photothermal effect was observed. Further studies have indicated that the Q[8] encapsulation-triggered PET cycle exhibited good repeatability without significant loss of its efficiency and had potential application in the fabrication of smart windows and erasable printing under photoirradiation or sunlight. These results suggest that the Q[8] host can be used as a new tool in light-energy conversion and photochromism materials science

Through-Space Conjugated Supramolecular Polymer Radicals from Spatial Organization of Cucurbit[8]uril: An Efficient Approach for Electron Transfer and Smart Photochromism Materials

Electron transfer-based long-lived radicals are highly challenging because of the limited control over relative orientation, distance, electronic coupling, and nonradiative recombination channels of the donor and acceptor on a molecular level. Herein, the cavity of macrocyclic cucurbit[8]uril (Q[8]) was found to exhibit excellent advantages in controlling the relative orientation and distance of the donor and acceptor moieties via the spatial organization, i.e., the 4-carboxylphenyl appended viologen-derived guest (BcpV2+) was elegantly rearranged as a rigid linear J-type supramolecular polymer by the Q[8] host via noncovalent interactions. Thus, an unprecedented photoinduced electron transfer (PET) triggered through-space conjugated organic radical with distinct photochromism and a NIR-II photothermal effect was observed. Further studies have indicated that the Q[8] encapsulation-triggered PET cycle exhibited good repeatability without significant loss of its efficiency and had potential application in the fabrication of smart windows and erasable printing under photoirradiation or sunlight. These results suggest that the Q[8] host can be used as a new tool in light-energy conversion and photochromism materials science

Through-Space Conjugated Supramolecular Polymer Radicals from Spatial Organization of Cucurbit[8]uril: An Efficient Approach for Electron Transfer and Smart Photochromism Materials

Electron transfer-based long-lived radicals are highly challenging because of the limited control over relative orientation, distance, electronic coupling, and nonradiative recombination channels of the donor and acceptor on a molecular level. Herein, the cavity of macrocyclic cucurbit[8]uril (Q[8]) was found to exhibit excellent advantages in controlling the relative orientation and distance of the donor and acceptor moieties via the spatial organization, i.e., the 4-carboxylphenyl appended viologen-derived guest (BcpV2+) was elegantly rearranged as a rigid linear J-type supramolecular polymer by the Q[8] host via noncovalent interactions. Thus, an unprecedented photoinduced electron transfer (PET) triggered through-space conjugated organic radical with distinct photochromism and a NIR-II photothermal effect was observed. Further studies have indicated that the Q[8] encapsulation-triggered PET cycle exhibited good repeatability without significant loss of its efficiency and had potential application in the fabrication of smart windows and erasable printing under photoirradiation or sunlight. These results suggest that the Q[8] host can be used as a new tool in light-energy conversion and photochromism materials science

B^III–Subporphyrins Bearing Distorted Metal-Coordinating Straps: Cu^II-Assisted <i>meso</i>-Fabrications

BIII-subporphyrins 4, 5, and 6 possessing metal-coordinating carbaporphyrin-like pockets were synthesized by Suzuki–Miyaura coupling reactions. Compounds 4 and 5 gave PdII complexes 4-Pd and 5-Pd upon metalation with Pd(OAc)2 but did not give either their NiII or CuII complexes. Conversely, 6 was expected to induce distorted square planar coordination because of its 2,5-di(pyrid-2-yl)pyrrole strap. Indeed reaction of 6 with Cu(OAc)2 did not give its CuII complex but produced meso-alkoxy and meso-phenoxy products in the presence of alcohols and phenol, possibly via CuII-mediated C–H bond functionalization, which was further extended to meso-C–C bond-forming fabrications by using organoboronic acids. These CuII-mediated C–H bond meso-fabrications are the first example for porphyrinoid substrates

Singly and Doubly Neo-Confused Smaragdyrins

Smaragdyrin had been an important but elusive expanded porphyrin until our recent first synthesis (Xie et al., J. Am. Chem. Soc. 2018, 140, 16553). In this paper, we report the synthesis of singly and doubly neo-confused [22]­smaragdyrin BF2-complexes 13 and 15 both as stable smaragdyrin mutants by nucleophilic substitution reactions of 1,9-dibromo-5-mesityldipyrrin 1 with singly and doubly N-confused tripyrranes, 10 and 11, respectively. Demetalation of 13 and 15 with methanesulfonic acid furnished singly and doubly neo-confused [22]­smaragdyrin free bases 16 and 18, respectively, both as air-sensitive porphyrinoids. These neo-confused [22]­smaragdyrin free bases display characteristic properties such as decreased diatropic ring current, regioselective diprotonation at the inner α-carbon of the neo-confused pyrrole to give 16H22+ and 18H22+, and smooth oxygenation at the inner α-position of the neo-confused pyrroles, giving neo-confused [22]­oxosmaragdyrin 17 and doubly neo-confused [24]­dioxosmaragdyrin Cu­(II) complex 19Cu via metalation of 18 with CuCl2 in the presence of NaOAc. Finally, demetalation of 19Cu with methanesulfonic acid gave the corresponding doubly neo-confused [24]­dioxosmaragdyrin 19

Singly and Doubly Neo-Confused Smaragdyrins

Smaragdyrin had been an important but elusive expanded porphyrin until our recent first synthesis (Xie et al., J. Am. Chem. Soc. 2018, 140, 16553). In this paper, we report the synthesis of singly and doubly neo-confused [22]­smaragdyrin BF2-complexes 13 and 15 both as stable smaragdyrin mutants by nucleophilic substitution reactions of 1,9-dibromo-5-mesityldipyrrin 1 with singly and doubly N-confused tripyrranes, 10 and 11, respectively. Demetalation of 13 and 15 with methanesulfonic acid furnished singly and doubly neo-confused [22]­smaragdyrin free bases 16 and 18, respectively, both as air-sensitive porphyrinoids. These neo-confused [22]­smaragdyrin free bases display characteristic properties such as decreased diatropic ring current, regioselective diprotonation at the inner α-carbon of the neo-confused pyrrole to give 16H22+ and 18H22+, and smooth oxygenation at the inner α-position of the neo-confused pyrroles, giving neo-confused [22]­oxosmaragdyrin 17 and doubly neo-confused [24]­dioxosmaragdyrin Cu­(II) complex 19Cu via metalation of 18 with CuCl2 in the presence of NaOAc. Finally, demetalation of 19Cu with methanesulfonic acid gave the corresponding doubly neo-confused [24]­dioxosmaragdyrin 19

Bottom-Up Synthesis of Multiply Fused Pd^II Anthriporphyrinoids

Anthriporphyrinoid and its dimeric homologues were synthesized by Suzuki–Miyaura coupling and subsequent oxidation. Both porphyrinoids were smoothly converted to their PdII complexes and were further decorated by Suzuki–Miyaura coupling with thiophene derivatives and subsequent oxidative fusion reaction to provide multiply fused compounds. Most PdII anthriporphyrinoids have been structurally well characterized to be planar for monomeric and helically twisted for dimeric species. The dimeric anthriporphyrinoids show paratropic ring currents due to their global antiaromatic networks, the extent of which increases with an increase of conjugated network. Multiply fused dimeric anthriporphyrinoids show helical structures, fully reversible six redox potentials, small HOMO–LUMO gaps, and absorption tails reaching in the near-infrared region, suggesting the high potential of this approach to explore molecular graphene. Optical separations of the dimeric helical species were accomplished, and racemization barrier heights were determined