Two novel LMOFs based on the flexible 1, 3-bis(imidazol-1-ylmethyl)benzene: The synthesis, crystal structures and temperature sensing applications

Fluorescence Thermometers Involving Two Ranges of Temperature: Coordination Polymer and DMSP Embedding

The measurement of temperature is indispensable in the fields of life, science, and industry. Fluorescence thermometers are attractive to researchers because of their advantages such as noncontact, high sensitivity, fast response, and excellent anti-interference. Here, a new coordination polymer (HNU-76) was synthesized by assembling Zn2+ with the H3TCA ligand, a fluorescent molecule with an AIE behavior, which can be used as a fluorescence thermometer. At 100-210 K, the fluorescence intensity ratio of HNU-76 versus temperature conforms to an Arrhenius-type decay relationship (R2 = 0.997), which can be the candidate for low-temperature sensing. In order to increase the sensing range, 4-[4-(dimethylamino)styryl] pyndine (DMSP) was successfully embedded on HNU-76, obtaining HNU-76⊃DMSP. The fluorescence intensity of HNU-76⊃DMSP conforms to an Arrhenius-type decay relationship (R2 = 0.997) at 270-360 K versus temperature. HNU-76 can be used for fluorescence detection at low temperatures, due to the DMSP loading, and HNU-76⊃DMSP can serve as the temperature thermometer in a range of temperatures common. Both materials show good cyclability and have the potential to be used in fluorescence thermometers.

Engineering of metal-organic frameworks (MOFs) for thermometry

Metal-organic frameworks (MOFs ) are excellent candidates for use in chemistry, material sciences and engineering thanks to their interesting qualitative features and potential applications. Quite interestingly, the luminescence of MOFs can be engineered by regulation of the ligand design, metal ion selection and encapsulation of guest molecules within the MOF cavity. Temperature is a very crucial physical parameter and the market share of temperature sensors is rapidly expanding with technology and medicinal advancement. Among the wide variety of available temperature sensors, recently MOFs have emerged as potential temperature sensors with the capacity to precisely measure the temperature. Lanthanide-based thermometry has advantages because of its ratiometric response ability, high quantum yield and photostability, and therefore lanthanide-based MOFs were initially focused on to construct MOF thermometers. As science and technology have gradually changed, it has been observed that with the inclusion of dye, quantum dots, etc. within the MOF cavity, it is possible to develop MOF-based thermometry. This review consolidates the recent advances of MOF-based ratiometric thermometers and their mechanism of energy transfer for determining the temperature (thermal sensitivity and temperature uncertainty). In addition, some fundamental points are also discussed, such as concepts for guiding the design of MOF ratiometric thermometers, thermometric performance and tuning the properties of MOF thermometers.

Hydrogen bonding-mediated assembly of carbon dot@Zr-based metal organic framework as a multifunctional fluorescence sensor for chlortetracycline, pH and temperature detection

Carbon dots@UiO-66(COOH)2 with multifunctional fluorescence responsibilities for chlortetracycline, pH, and temperature detection is prepared via a hydrogen bond-driven solvent-free strategy.