Auxiliary ligand-assisted structural diversities of three metal–organic frameworks with potassium 1H-1,2,3-triazole-4,5-dicarboxylic acid: syntheses, crystal structures and luminescence properties

Twelve Cadmium(II) Coordination Frameworks with Asymmetric Pyridinyl Triazole Carboxylate: Syntheses, Structures, and Fluorescence Properties

“…Compared to the pmtcLi ligand, the emission bands of 1 – 4 , 6 , and 9 – 11 are 6, 10, 22, 0, 12, 6, 43, and 29 nm blue-shifted, respectively, while the emission bands of 5 are 11 nm red-shifted. The luminescence of 1 – 6 and 9 – 11 should be assigned to the intraligand π → π* and/or n → π* transitions, whereas the less than 50 nm wavelength shifts are probably caused by the coordination effect. − For 1 , 5 , 6 , and 9 , the effective enhancement of emission bands should be due to the formation of various noncovalent interactions, which effectively increases the rigidity of organics and reduces the nonradiative decay of the intraligand excited state. However, SCN – or SO 4 2– in 2 , 3 , and 4 have a negative effect on the fluorescence intensity, which results in the significant weaken of emission bands. − ,− Furthermore, there are stacking interactions in 3 / 4 with the center-to-center separations of 3.456/3.773 Å, respectively, which has also the negative effect on the fluorescence intensity.…”

Ag+, Fe3+and Zn2+-intercalated cadmium(ii)-metal–organic frameworks for enhanced daylight photocatalysis

“…The free H 4 btec linkers exhibit weaker luminescence emission bands at 397 nm, signifying the intraligand (p*-s or p*-p) emission. 54,55 The emission maxima of Ag and Zn ion-intercalated MOF showed an emission peak in the near visible region i.e., 420 nm and 425 nm, respectively, with a slightly extended spectrum covering the visible light zone. The Fe 3+ -intercalated MOF showed maximum emission at 440 nm upon excitation at 325 nm with a wider and broader spectrum covering the complete visible spectrum till 650 nm.…”

Different Benzendicarboxylate-Directed Structural Variations and Properties of Four New Porous Cd(II)-Pyridyl-Triazole Coordination Polymers

“…The four complexes have their specific emissions, the bands of which were presented at 425 nm (λ ex = 321 nm) for 1, 380 nm (λ ex = 305 nm) for 2, 360 nm (λ ex = 289 nm) for 3, as well as 386 nm (λ ex = 336 nm) for 4, respectively. These emission bands are greatly similar to the free Hmdpt emission for the π-π * or n-π * intra-ligand transition (Sun et al, 2013;Wenger, 2013;Zou et al, 2013;Chen et al, 2017). In contrast to the Hmdpt, the emissions of four CPs have the similar blue shifts, which are considered to be the energy transfer from the Hmdpt ligand to the Cd(II) centers for the ligand-to-metal charge transfer (LMCT) (Cao et al, 2017).…”