Photochromic and Room Temperature Phosphorescent Donor–Acceptor Hybrid Crystals Regulated by Core-Substituted Naphthalenediimides

Abstract

Donor−acceptor (D−A) hybrid crystals are an emerging kind of crystalline hybrid material composed of semiconductive inorganic donors and organic acceptors. Except for the intrinsic photochromism, recently we have reported that the anion-π polyoxometalate (POM)/naphthalenediimide (NDI) hybrid crystals could produce an interesting room temperature phosphorescence (RTP) quantum yield up to 7.2%. Herein, we extended into coresubstituted NDIs and anticipated the regulation of their photochromic and RTP properties. Thus, two hybrid crystals, namely (H 4 BDMPy-Br 2 NDI)•(NMP) 4 •(HPW 12 O 40 ) (1) and (H 4 BDMPy-I 2 NDI)• (HPW 12 O 40 ) (2) (H 2 BDMPy-Br 2 NDI: N,N′-bis(3,5-dimethylpyrazolyl)-2,6-dibromo-1,4,5,8-naphthalenediimide and H 2 BDMPy-I 2 NDI: N,N′-bis(3,5-dimethylpyrazolyl)-2,6-diiodide-1,4,5,8-naphthalenediimide), have been synthesized from phosphotungstic anions (PW 12 O 40 3− ) and Br or I core-substituted NDIs. Compared to the coreunsubstituted analogues (H 4 BDMPy-NDI)•(NMP) 4 •(HPW 12 O 40 ) ( 3), 2 with photosensitive iodine substituents is more sensitive to light, which can become discolored under natural light. As a result of the heavy-atom effect, hybrid 1 exhibits remarkable RTP with the quantum yield up to 10.2% and a lifetime of 1.14 ms.

Solvent-Modulated Self-Assembly of Naphthalenediimide-Based Cd(II) Complexes and the Controllable Photochromism via Conformational Isomerization

“…The binding energies of N 1s are 400.02 and 402.07 eV before visible light irradiation and 399.27 and 401.22 eV after radiation, which indicates that the N atoms get electrons . The total signal of O 1s binding energy after photochromic was 0.58 eV higher than that of the unirradiated sample (531.17 eV for 2 and 531.75 eV for 2-P ), indicating that the O atom lost electrons . As a conclusion, the [NDI] − · radical that results from the ET interaction between the N atom of the NDI ligands and the O atom of the carboxylic acid should be the source of the photochromic behavior of 2 …”

“…48 The total signal of O 1s binding energy after photochromic was 0.58 eV higher than that of the unirradiated sample (531.17 eV for 2 and 531.75 eV for 2-P), indicating that the O atom lost electrons. 49 As a conclusion, the [NDI] −• radical that results from the ET interaction between the N atom of the NDI ligands and the O atom of the carboxylic acid should be the source of the photochromic behavior of 2. 50 Conformational Isomerization-Controlled Photochromism.…”

Grain boundaries passivation of high efficiency and stable perovskite photodetector by polyoxometalate-based composite SiW 11@ZIF-8

“…Polyoxometalates (POMs) are a class of multinuclear complexes that can be used as modified materials in the field of perovskite photovoltaics [27][28][29] due to their unique photosensitivity [30][31][32] and redox properties [33][34][35]. The photosensitivity of POMs can improve the light absorption of perovskite, thereby increasing the number of photogenerated carriers in the device [27,36].…”

The modulation effect of an electron-rich guest on the luminescence of naphthalene diimide-based metal–organic frameworks

“…In addition to the strategies mentioned above, some other special methods are also used to regulate the luminescence of MOFs, such as halogen bonding, hydrogen aggregation, and anion-π interactions. [23][24][25][26][27][28] Recently, host-guest chemistry, especially host-guest systems based on charge-transfer complex interactions have attracted considerable attention, as it revealed a new method for the preparation of luminescent MOFs. [29][30][31][32] Since emission from host-guest charge transfer materials results mainly from the charge transfer between the acceptor's (host) lowest unoccupied molecular orbital (LUMO) and the donor's (guest) highest occupied molecular orbital (HOMO), the emission wavelength of host-guest systems could, therefore, be readily modulated and predicted based on the rational utilization of donors and acceptors.…”

“…In addition to the strategies mentioned above, some other special methods are also used to regulate the luminescence of MOFs, such as halogen bonding, hydrogen aggregation, and anion–π interactions. 23–28…”