Trace Water In Organic Solvents Research Articles

N-hydroxypropyl substituted 4-hydroxynaphthalimide: Differentiation of solvents and discriminative determination of water in organic solvents

A naphthalimide-based fluorophore (HONIOH) was designed by introducing a hydroxy unit into the 4th position of the aromatic core and a hydroxypropyl unit into the N-imide site. Photophysical properties of HONIOH were highly dependent on solvents, which was ascribed to the excited state proton transfer (ESPT) coupled with intramolecular charge transfer (ICT) mechanism. Further studies demonstrated that HONIOH can be used to recognize N, N-dimethylformamide (DMF) qualitatively and differentiate methanol from ethanol. Three control compounds were synthesized, their photophysical properties were investigated in various solvents, and experimental results revealed that hydroxyl and hydroxypropyl units contribute to the solvents differentiation ability of HONIOH. In addition, HONIOH was successfully applied as a colorimetric, fluorescent probe for the discriminative detection of trace water in organic solvents, such as fluorescence turn-on response accompanied by fluorescent color changes from light yellow to purple in DMF, and fluorescence turn-off response and blue to yellow fluorescent color changes in acetonitrile, tetrahydrofuran, and acetone. We believe that N-substituted 4-hydroxynaphthalimide derivatives may find widespread applications in chemical and biochemical sensing and imaging.

Luminescence of CeI3 in organic solvents and its application in water detection

Molecular Ce(III) complexes are newly developed luminophores that have potential applications in a number of fields. However, there have been very limited studies regarding the application of solvoluminescent Ce(III) complexes. In this paper, we report the luminescence of CeI3 in different organic solvents. Violet or blue emissions were observed for CeI3 dissolved in THF, CH3CN and Et2O under ultraviolet irradiation. The luminescent properties are correlated with the structures of solvated complexes as exemplified in the CeI3(THF)4 case. The solvoluminescence is strongly affected by the presence of water which converts solvated Ce(III) into cerium hydrates. The concentration of water lowered to 0.1 vol% was tested in THF, CH3CN and Et2O, indicating the potential application of commercial CeI3 as a convenient luminescent sensor for the detection of trace water in organic solvents.

Luminescence of CeI3 in Organic Solvents and its Application in Water Detection

Molecular Ce(III) complexes are newly developed luminophores that have potential applications in a number of fields. However, there have been very limited studies regarding the application of solvoluminescent Ce(III) complexes. In this paper, we report the luminescence of CeI 3 in different organic solvents. Violet or blue emissions were observed for CeI 3 dissolved in THF, CH 3 CN and Et 2 O under ultraviolet irradiation. The luminescent properties are correlated with the structures of solvated complexes as exemplified in the CeI 3 (THF) 4 case. The solvoluminescence is strongly affected by the presence of water which converts solvated Ce(III) into cerium hydrates. The concentration of water lowered to 0.1vol% was tested in THF, CH 3 CN and Et 2 O, indicating the potential application of commercial CeI 3 as a convenient luminescent sensor for the detection of trace water in organic solvents.

Covalent Organic Frameworks with Electron‐Rich and Electron‐Deficient Structures as Water Sensing Scaffolds

Covalent organic frameworks (COFs) have potential applications in gas storage, catalysis, proton conduction, sensing, and chemical removal etc., due to their highly crystalline structure, good stability, porosity, as well as structural and functional controllability. Herein, by using electron-rich group, 2,5-bis(methylthio)terephthalaldehyde (BMTA), and electron-deficient group, 1,3,5-tris-(4-aminophenyl)triazine (TAPT) as building blocks, TAPT-BMTA-COF is constructed through Schiff-base reaction. TAPT-BMTA-COF has high crystallinity, porosity, big Brunauer-Emmett-Teller surface area (BET), good chemical and thermal stability, and commendable solvatochromic properties. It can be used as the water sensing scaffold to detect the trace water in organic solvents due to the fluorescence quenching of the COF caused by the interaction between water and TAPT-BMTA-COF.

Barium charge transferred doped carbon dots with ultra-high quantum yield photoluminescence of 99.6% and applications

Long-emission carbon dots (CDs) is triggering immense enthusiasm on account of their intrinsic merits of high chemical stability and excellent optical properties. In this study, a facile and rapid approach was developed for the preparation of barium-doped carbon dots (Ba-CDs) with yellow fluorescence emission and high quantum yields. Surface chemistry and the chemical architecture of the Ba-CDs was revealed under various spectroscopic methods. This work provides more insights into the effects of charge transfer caused by Ba heteroatoms, which is considered as the most challenging step in the investigation on luminescence mechanism. Remarkably, the prepared Ba-CDs were successfully applied as fluorescent probes in the detection of trace water in organic solvents (ethanol, isopropanol, acetone, tetrahydrofuran). Comparing with traditional fluorescent probes for water detection in organic solvents, Ba-CDs detection provides a more sensitive, much faster and more economical approach.

Visual monitoring of trace water in organic solvents based on ecofriendly b/r-CDs ratiometric fluorescence test paper

Developing a green, non-toxic and easy to synthesize of fluorescence probe for fast and visual detecting trace water in various organic solvents was an important task. Here, a novel dual-emission fluorescence probe (b/r-CDs) was designed based on the red CDs (r-CDs) and blue CDs (b-CDs) to detect the trace water and enhance the visualization for naked-eye observation in different organic solvents. Among, the red fluorescence carbon dots (CDs) was found to have the capability to monitor trace amounts of water, which synthesized with green tea by facile ultrasonic method. Further, Such a dual-emission probe could fast monitor trace water in various organic solvents with high stability and fast response. Importantly, a synergistic mechanism of the dynamic process (b-CDs) and static quenching (r-CDs) was proved for the study of water detection. Moreover, the test paper was made for detecting trace water in different organic solvents, achieving convenient and effective detection.

Multifunctional Carbon Dots for Trace Water Detection, White LEDs, and Bioimaging

AbstractHighly fluorescent, ultrafine CDs were synthesized by a simple one‐pot solvothermal method. The as‐prepared CDs exhibited unique yellow emission and intrinsic fluorescence characteristics independent of excitation wavelengths. We revealed a distinct fluorescence quenching mechanism in the CDs, where the reversible alternation between aggregation and dispersion states can mediate the fluorescence turn‐on and turn‐off response. Therefore, the CDs can be used as a fluorescence nanoswitch for the highly sensitive quantitative detection of trace water in organic solvents. We also demonstrated the applications of the CDs as a stable yellow phosphor and biological probe for white LEDs and biomembrane imaging. Our results suggest that the low‐cost fluorescent material has great promise for practice applications in sensing, bioimaging, and optoelectronic device.

Tetraphenylethene-substituted benzothiadiazoles: AIE and TICT properties, tunable intramolecular conjugation and application in detecting trace water in organic solvents

A series of tetraphenylethylene-based benzothiadiazole derivatives (TPEB-o-NO2, TPEB-m-NO2, and TPEB-p-NO2) were designed and synthesized by adjusting the linkage model of nitro group. Different substituent positions of nitro group lead to different intramolecular conjugation of compounds TPEB-o-NO2, TPEB-m-NO2, and TPEB-p-NO2, thus resulting in different photophysical properties. Their maximum emission gradually red-shifted when changing the connected position of nitro group from ortho-position to meta-position and to para-position. TPEB-o-NO2, TPEB-m-NO2, and TPEB-p-NO2 exhibit interesting solvatochromic effects and “on–off–on” optical switch behavior owing to the combined action of AIE and TICT. Moreover, TPEB-m-NO2 and TPEB-p-NO2 were successfully applied as highly sensitive sensors in quantitatively detecting trace water in tetrahydrofuran (THF), dioxane (Diox) and ethyl acetate (EA). The DL of TPEB-m-NO2 and TPEB-p-NO2 are, 0.039% and 0.014% for THF, 0.021% and 0.009% for EA, 0.033% and 0.018%(v/v) for Diox, respectively. It is worth mentioning that TPEB-m-NO2, and TPEB-p-NO2 can act as sensitive indicator for monitoring trace water fraction in organic solvent rectification, which is much more convenient and intuitive to estimate the real-time water content approximately than traditional method.

Core-shell upconversion nanoparticles of type NaGdF4:Yb,Er@NaGdF4:Nd,Yb and sensitized with a NIR dye are a viable probe for luminescence determination of the fraction of water in organic solvents.

Lanthanide-doped core-shell upconversion nanoparticles (UCNPs) of type NaGdF4:Yb,Er@NaGdF4:Yb,Nd were prepared by the co-precipitation method. The luminescence intensity was further enhanced by adding the sensitizer dye IR-808. If water is added to organic solvents [such as N,N-dimethylformamide (DMF), dimethyl sulfoxide, methanol, acetone, acetonitrile, and ethanol] containing the probe, its luminescence intensity peakingat 545nm is reduced. The decrease is linearly related to the percentage of water in the respective organic solvent. Water fractions ranging from 0.05% to 10% (volume %) can be sensitively detected, and the detection limit is 0.018% of water in DMF. The detection scheme is mainly attributed to the fact that the transfer of energy from the near-infrared light (NIR) dye to the UCNPs is strongly reduced in the presence of traces of water. Graphical abstract The near infrared dye (IR-808) transfer efficiency to NaGdF4:Yb, Er@NaGdF4:Yb, Nd upconversion nanoparticlesin water is far less than that in organic phase. Several methods for determination of trace water in organic solvents were developed by using this effect.

Aldehyde-derivatized indoles as fluorescent probes for hydration environments

Tryptophan derivatives have long been used as site-specific fluorescent probes. 4-cyanotryptophan emits in the visible region and is the smallest blue fluorescent amino acid probe. We performed UV–Vis, steady-state and time-resolved fluorescence spectroscopy on six aldehyde-derivatized indoles dissolved in water and found that indole-4-carboxaldehyde (I4A) has the largest redshifts among all reported indole derivatives and can emit in the green region of the visible spectrum, which suggests that substitution of the indole ring of Trp using I4A may make a green fluorescent amino acid probe. It differs from tryptophan by only 3 atoms and will be the smallest green fluorescent amino acid probe that has great potential to be used in spectroscopic and microscopic measurements of proteins. We also found that I4A could be used as a fluorescent probe to detect trace water in organic solvents since its maximum emission wavelength is extremely sensitive to local hydrogen-bonding status.

A reversible ratiometric fluorescence probe for fast detection of trace water in different organic solvents

We have developed a new ratiometric fluorescence probe that was constructed by dansyl and rhodamine mimic and based on Förster resonance energy transfer (FRET) platform. The probe could fast monitor trace water in organic solvents with high sensitivity and reversibility. To the best of our knowledge, this is a first ratiometric fluorescence probe based on organic small molecule for trace water in organic solvents. Moreover, test strips were made and used to detect water in organic solvents easily. In addition, Gibbs free energy in different solvents was calculated.

Excited State Intramolecular Proton Transfer Plus Aggregation-Induced Emission-Based Diketopyrrolopyrrole Luminogen: Photophysical Properties and Simultaneously Discriminative Detection of Trace Water in Three Organic Solvents.

Developing solid state near-IR (NIR) emitters and simultaneously discriminative detection of trace water in organic solvents has long been a significant challenge. In this work, a novel diketopyrrolopyrrole-based luminogen (DPP1) with excited state intramolecular proton transfer (ESIPT) and aggregation-induced emission (AIE) characteristics has been designed and synthesized. Its amorphous and crystal solids show red and NIR-emissive fluorescence at 625 and 675 nm, respectively. When DPP1 reacts with fluoride anion, the resulting system (DPP1·F) can discriminatively detect the water content in aprotic solvents with colorimetric and fluorescent dual modes. Distinct fluorescent responses of "turn-on", "ratiometric turn-off", and "ratiometric turn-on" and low limits of detection of 0.0064, 0.042, and 0. The water-induced sensitive and fast change in THF was applied to the determination of water in foodstuffs in practical solid state indicator paper strips.

An AIE dye based smartphone and LDA integrated portable, intelligent and rapid detection system as trace water indicator and cyanide detector

Portable, rapid, accurate and on-site detection of analysis target has always been the goal of continuous efforts in the field of analysis. In this work, a novel intelligent and rapid detection system based on an AIE dye (TPA-DCV) was established for portable and on-site detection of trace water in organic solvents and CN− in water by integrating the smartphone and linear discriminant analysis (LDA). The TPA-DCV displayed remarkable solvatochromism effect and showed different fluorescence colors to different water contents of different solvents, with the minimum detection limit of 54 ppm. In addition, TPA-DCV also exhibited specific response to CN−, and showed significant fluorescence changes to different amounts of CN−. With the assist of this detection system, these different fluorescence color signals could be accurately classified in canonical score plot. What's more, the classification and distribution of fluorescence color in canonical score plot showed regular change with the target concentration, which could be used to quantify the trace water and CN−. The rationality and practicability of this detection system were preliminary verified by a large number of real sample analyses. This detection system greatly simplifies the analysis process, which is in the proof of intelligent and rapid detection just using a simple color analysis without any instrument test, which may be a big step forward.

Real-time colorimetric water content monitoring of organic solvents by an azo dye incorporated into AlPO4-5 nanochannel

Azo dye/AlPO4-5 composite for rapid quantitative detection of trace water in organic solvents.

A FRET-based ratiometric fluorescent probe for sensing trace water in organic solvents

A new ratiometric fluorescent probe for the detection of water in organic solvents with low limit of detection and large Stokes shift.

Highly Sensitive Luminescent Probe of Aniline and Trace Water in Organic Solvents Based on Covalently Modified Lanthanide Metal–Organic Frameworks

A novel europium functionalized metal–organic framework (MOF) named Eu3+@UiO-66-NH2-IM is robustly synthesized via covalent PSM (postsynthetic modification). The ligand of matrix MOF is covalently ...

Synthesis of copper nanoclusters stabilized by 2-amino-5-mercapto-1, 3, 4 -thiadiazole and acetate simultaneously and as a sensitive sensor for detecting trace water in organic solvents

We describe the synthesis of a novel copper nanoclusters (AMTD-Ac-CuNCs) stabilized by 2-amino-5-mercapto-1,3,4-thiadiazol (AMTD) and acetate (Ac-) simultaneously. The effect of carboxylate on the luminescence of CuNCs was discussed. The as-synthesized CuNCs can be used as a highly sensitive fluorescence sensor to successively detect the trace water in organic solvents. The sensor exhibits high sensitivity with a detection limit as 0.036% for water in EtOH, 0.018 v/v % in THF, 0.024 in ACT and 0.026 in MeCN, respectively. This work broadens the application of CuNCs and provides an extremely sensitive detection method of water.

Ratiometric fluorescence detection of trace water in organic solvents based on aggregation-induced emission enhanced Cu nanoclusters.

A fast, sensitive, and convenient dual-emission water detector was robustly fabricated. This detector was prepared with blue fluorescent carbon dots (CDs) and red fluorescent Cu nanoclusters (NCs), and showed two well-resolved and intensity-comparable fluorescence peaks under a single excitation wavelength. Moreover, it showed strong red fluorescence in organic solvent due to the aggregation-induced emission enhancement (AIEE) properties of the Cu NCs, but the red fluorescence was gradually quenched with an increasing amount of water, whereas the blue fluorescence remained constant. The differences in response result in a continuous fluorescence color change from red to blue that can be clearly observed by the naked eye. Thus, as-prepared Cu NC-based dual-emission nanomaterials can be used for ratiometric fluorescence detection of trace amounts of water in organic solvents by taking advantage of the water sensitivity of their fluorescence intensity ratios (red/blue) and their low detect limits (<0.02% v/v). These studies demonstrate that a novel and sensitive dual-emission ratiometric water detector has been found, which shows promise for application in environmental monitoring, food inspection, and life science.

A sensitive fluorescent sensor for the detection of trace water in organic solvents based on carbon quantum dots with yellow fluorescence.

The quantitative analysis of trace water in organic solvents has always been a research hotspot, and it is still in the development stage and needs to be continuously developed. In this study, a facile and rapid approach was developed for the preparation of carbon quantum dots (CQDs) with yellow fluorescence emission and ultrahigh absolute fluorescence quantum yields (92.6%). Compared to traditional organic fluorescent molecules, the preparation of CQDs is simpler, faster and more environmentally friendly. It is found that the fluorescent properties of CQDs are excellent in organic solvents and could be quenched by trace water, which makes them a promising material used without any modification for the detection of water in organic solvents. As a result, the as-prepared CQDs were adopted as fluorescent probes for the detection of water in organic solvents (ethanol, tetrahydrofuran, and 1,4-dioxane). The limit of detection was as low as 0.01%. To the best of our knowledge, this is the first time that CQDs have been used as water sensing fluorescent probes in organic solvents. The possible mechanism for trace water detection of the as-prepared CQDs in organic solvents is attributed to the specific water–fluorophore interaction and partially to the increase in polarity of the solvent caused by an increase in water concentration.

Q-Graphene-loaded metal organic framework nanocomposites with water-triggered fluorescence turn-on: fluorimetric test strips for directly sensing trace water in organic solvents.

A solid-state fluorimetric strategy has been developed using test strips coated with Q-graphene-loaded metal-organic framework nanocomposites featuring water-triggered fluorescence turn-on. It can facilitate the real-time evaluation of trace water in organic solvents, with the level down to about 0.015% in alcohol.