Synthesis And Study Of Fluorescence Temperature Probe Based On Triarylphosphoryl Compounds Containing Tetrahydropyrrole Or Carbazole Group

Temperature is one of the most basic physical parameters in daily life and scientific technology.The development of temperature sensing plays a significant role in the fields of metrology,aerodynamics,meteorology,oceanography,chemistry,biology,pharmacy,and military.etc.In science,all physicochemical phenomena and chemical reactions are affected by temperature.Therefore,many sensing methods for temperature have been invented and developed according to different physicochemical properties,such as volume expansion thermometers,infrared thermometers and thermocouples.However,each temperature sensor has its own intrinsic defects,such as poor spatial resolution or only take measurements of the object surfaces.Luminescent temperature sensing,as a new method for temperature measurement,has received much attention because of its fast response,high spatial resolution and sensitivity,in-situ measurement,and not disturbed by strong electric and magnetic fields.There are mainly three methods for fluorescence temperature probes: measurement of luminescence intensity,ratiometric intensity,and lifetimes.Many current temperature probes based on luminescent intensity can measure temperature simply and quickly.However,their intensities or accuracies are affected by amounts of chromophores,excitation power,distribution or corresponding absorption from testing samples.Luminescent lifetime based thermometers would overcome many problems of intensity-based measurements and provide accurate results.However,they require expensive measurement instruments and time-consusimg,sophisticated calculations.In contrast,ratiometric fluorescence sensors show better accuracy and sensitivity than single-wavelength ones due to the different response characteristics of the two wavelengths luminescent peak of the temperature and excellent self-correcting characteristics.Currently,many kinds of ratiometric sensing systems have been developed,which are based on doped polymer temperature probe,excimer temperature probe,based on local excited state and twisted intramolecular charge transfer state ratiometric fluorescence temperature thermometers.To date,high-temperature luminescence sensing is to realize.This is because increasing the temperature significantly lowers the sensitivity and accuracy,due to much facilitated nonradiative decay in the luminphores at high temperatures.Therefore,it is essential to design high-temperature and wide-range ratiometric luminescent temperature sensing materials in both scientific and practical views.In this work,two types of ratiometric fluorescent temperature-sensing materials based on triarylphosphoryl compounds containing tetrahydropyrrole groups or carbazole groups have been developed.Their dual emissions come from local excited state(LE)and charge transfer(CT)state,respectively.The sensing mechanism was studied by investigation of temperature-dependent lifetime.Varying temperature changes the distribution equilibrium of the two excited states,leading to change in the ratio of the two luminescence peaks.Also,we explored the temperature response performance of these materials in the wider temperature range and the common temperature range(223-333 K)of the solvent sample.At higher temperatures,the ratiometric fluorescence thermometers remains high luminescence intensity and obvious variation of luminescence ratio.Thus,high sensitivity of their temperature sensing can be realized in high temperature and wide temperature range.These advantages indicate promising prospects in practical applications.