Singlet oxygen (1O2), as a reactive oxygen species, has garnered serious attention in physical, chemical, and biological studies. In this paper, we designed and synthesized a new type of singlet-oxygen generation system by exchanging cationic ruthenium complexes (RCs) into anionic bio-MOF-1. The resulting bio-MOF-1&RCs can be used as effective photocatalysts for generation of singlet oxygen under both single-photon and two-photon excitation. Especially, the excellent two-photon absorption (TPA) behavior of bio-MOF-1&RCs aroused our interest greatly because their two-photon absorption band lies in the optical window of biological tissue. Here, we measured the ability of bio-MOF-1&RCs to generate 1O2 by irradiation under both 490 and 800 nm wavelength light in DMF. 1,3-Diphenylisobenzofuran (DPBF) and 2′,7′-dichlorofluorescein (DCFH) were used as typical 1O2 traps to detect and evaluate the efficiency of generation of 1O2 under single-photon and two-photon excitation, respectively. Results indicated that bio-MOF-1&[Ru(phen)3]2+ was able to effectively generate 1O2 under both conditions. Our work creates a novel synergistic TPA system with the excellent photophysical properties of RCs and the unique microporous structure benefit of MOFs, which may open a new avenue for creation of a cancer treatment system with both photodynamic therapy and chemotherapy.Keywords: metal−organic frameworks; photosensitizers; ruthenium(II) complexes; singlet oxygen; two-photon absorption

Two mononuclear and one binuclear Cu(I) complexes that contain imidazole derivative ligands including 2-(2′-pyridyl)imidazole (L1), 2-(2′-pyridyl)benzimidazole(L2), and 2,6-bis (benzimidazol-2yl)-pyridine (L3) were synthesized. The formulas of these complexes are [CuL1(PPh3)2][BF4] (1), [CuL2(PPh3)2][BF4] (2), [Cu2(L3)2(PPh3)2][BF4]2 (3), respectively. The crystal structures of complexes 1–3 have been determined by single-crystal X-ray diffraction analyses. The Cu(I) ions in the complexes have a distorted tetrahedral geometry. Photophysical properties of complexes 1–3 were systematically studied. These complexes maximum emission are mainly concentrated in the 623–680 nm. An electroluminescent (EL) device using 2 as the emitter was fabricated. The device produced a red emission which matches with the PL spectrum. However, the EL device of 2 is unfavorable. The absorption properties of complexes 1 and 2 were theoretically analyzed by time-dependent density functional theory (DFT).The calculated results are in good agreement with the experimental data.Graphical abstractWe present herein the synthetic route of complex 1which is capable of producing MLCT phosphorescent emission.Highlights► The crystal structures of complexes 1–3 are good. ► Complex 3 is a novel binuclear in Cu(I) complexes. ► These complexes have phosphorescent properties. ► These complexes have electroluminescent properties.

In this paper, we synthesized complexes of imidazole derivatives. The structures of complexes Ni(L1)2(CNS)2 (complex 1), Zn(L2)2(CNS)2 (complex 2) and MnL3Cl2 (complex 3) were determined by X-ray diffraction in those complexes. The space groups of complex 1, 2 and 3 are C2c/c, P-1 and P21/n, respectively. Ni (II), Zn (II) ions are coordinated by four nitrogen atoms of ligands and two nitrogen atoms of thiocyanate. Mn(II) ion is coordinated by three nitrogen atoms of ligand and two chlorine atoms. Single crystal X-ray studies on complex 2 and complex 3 indicate that the molecules of the complexes 2 and 3 link together through intermolecular NH⋯S hydrogen bonds and NH⋯Cl hydrogen bonds, respectively. The DFT (Density Functional Theory) and luminescent properties of these complexes are discussed. The calculated results are in good agreement with the experimental data.Highlights► SCN− as ligand in the complexes. ► The crystal structures of complexes 1–3 are good. ► Luminescent properties of these complexes are good.