Exploitation of room temperature (RT) photochromism and photomagnetism to induce single-molecule magnet (SMM) behavior has potential applications toward optical switches and magnetic memories, and remains a tremendous challenge in the development of new bulk magnets. Herein, a series of chain complexes [Ln 3 (H−HEDP) , and Y (QDU-1(Y)); HEDP = hydroxyethylidene diphosphonate; TPT = 2,4,6-tri(4-pyridyl)-1,3,5-triazine) were synthesized by solvothermal reactions. All the compounds exhibited reversible photochromic and photomagnetic behaviors via UV light irradiation at RT, induced by the photogenerated radicals via a photoinduced electron transfer (PET) mechanism. More importantly, the PET process induced significant variations in magnetic interactions for the Dy(III) congener. Strong ferromagnetic coupling with remarkably slow magnetic relaxation without applied dc fields was observed between Dy III ions and photogenerated O • radicals, showing SMM behavior after RT illumination. For the first time, we observed the reversible RT photochromism and photomagnetism in the lanthanide-based materials. This work realized the radicals-actuated on/off SMM behavior via RT light irradiation, providing a new strategy for constructing the lightinduced SMMs.

Three novel hybrid cuprous halides, [Me3TPT][Cu5I8] (1, Me3TPT = N,N',N''-trimethyl-2,4,6-tris(4-pyridyl)-1,3,5-triazine), [Et3TPT][Cu5I8] (2, Et3TPT = N,N',N''-triethyl-2,4,6-tris(4-pyridyl)-1,3,5-triazine), and [Me3TPT][Cu5Br8] (3), were solvothermally prepared by using in situ N-alkylated 2,4,6-tri(4-pyridyl)-1,3,5-triazine (TPT) derivatives as structure-directing agents. All the compounds feature layered structures extended by two types of building units, i.e. the chain-like Cu3I6/Cu3Br7 ({Cu3}) cluster and ribbon-like Cu4I10/Cu4Br10 ({Cu4}) cluster. UV-Vis spectra analyses indicate that they are potential semiconductor materials with narrow energy gaps of 1.05, 1.02, and 1.30 eV, respectively. These materials exhibit stable catalytic activity in the sunlight-driven degradation of organic dyes. Theoretical studies revealed that the N-alkylated TPT moieties contributed to the narrow semiconducting behavior, which results in the excellent visible light-driven photocatalytic activity.

The coordinative linkage of supramolecular zincophosphate building units and a non-photochromic dipyridine unit generates two hybrid photochromic frames.

Through regulating the pH values, a series of iodo‐argentate/cuprate hybrids, [Me3(4‐TPT)]4[Ag6I18] (1, Me3(4‐TPT)=N,N′,N′′‐trimethyl‐2,4,6‐tris(4‐pyridyl)‐1,3,5‐triazine), [Me3(4‐TPT)][M5I8] (M=Ag/2, Cu/2 a), [Me3(3‐TPT)][M5I8] (Me3(3‐TPT)=N,N′,N′′‐trimethyl‐2,4,6‐tris(3‐pyridyl)‐1,3,5‐triazine, M=Ag/3, Cu/4), which exhibit adjustable structural variations with different dimensional structures, have been obtained under solvothermal conditions. They are directed by two types of in situ N‐alkylation TPT‐derivatives (Me3(4‐TPT) for 1/2/2 a and Me3(3‐TPT) for 3/4) and represent the isolated units (1), 1D polymeric chain (4), 2D layered structures (2/2 a, 3) based on diverse metal iodide clusters. These compounds possess reducing band gaps as compared with the bulk β‐AgI and CuI and belong to potential semiconductor materials. Iodocuprates feature highly efficient photocatalytic activity in the sunlight‐induced degradation of organic dyes. The detailed study on the possible photocatalytic mechanism, including radical trapping tests and theoretical calculations, reveals that the N‐alkylation TPT moieties contribute to the narrow semiconducting behavior and effectively inhibit the recombination of photogenerated electron‐hole pairs, which result in an excellent visible‐light‐induced photocatalytic performance.

The photochromic performance of two hybrid zincophosphite frames could be tuned via enlarging the conjugated length of the non-photochromic bipyridine unit.