38660-35-4

Usage

Uses

Used in Analytical Chemistry:
3',6'-bis(diethylamino)-2-phenylspiro[1H-isoindole-1,9'-[9H]xanthene]-3(2H)-one is used as a pH indicator for monitoring changes in acidity and alkalinity in chemical and biological systems. Its reversible color change from pink to colorless upon exposure to different pH levels allows for the precise tracking and measurement of pH variations, which is crucial in various analytical processes.
Used in Photochromic Materials:
3',6'-bis(diethylamino)-2-phenylspiro[1H-isoindole-1,9'-[9H]xanthene]-3(2H)-one is utilized in the development of photochromic materials due to its reversible photoisomerization behavior. Its ability to change color upon exposure to light makes it a promising candidate for applications in smart materials and devices that can respond to light stimuli.
Used in Sensor Technology:
3',6'-bis(diethylamino)-2-phenylspiro[1H-isoindole-1,9'-[9H]xanthene]-3(2H)-one is employed in the creation of sensors that can detect and respond to changes in environmental conditions, such as pH levels. Its sensitivity to pH variations and reversible color change make it an ideal component for designing sensors with high selectivity and responsiveness.
Used in Materials Science:
In the field of materials science, 3',6'-bis(diethylamino)-2-phenylspiro[1H-isoindole-1,9'-[9H]xanthene]-3(2H)-one is explored for its potential in developing new materials with unique properties. Its photophysical and pH-sensitive characteristics can contribute to the creation of advanced materials with applications in various industries, including electronics, pharmaceuticals, and environmental monitoring.

Upstream product

• 81-88-9 rhodamine B 
• 62-53-3 aniline 
• 509-34-2 rhodamine B 
• 10025-87-3 trichlorophosphate 

Relevant academic research and scientific papers

A new rhodamine-based fluorescent chemosensor for transition metal cations synthesized by one-step facile condensation

A new rhodamine-based fluorescent chemosensor (1) for transition metal cations was synthesized by one-step facile condensation of rhodamine B and 2-aminopyridine. Without metal cations, 1 is colorless and nonfluorescent, whereas addition of metal cations (Fe3+, Hg2+, Pb2+, and Fe2+) leads to an obvious color change to pink and an appearance of orange fluorescence.

The utilization of pH sensitive spirocyclic rhodamine dyes for monitoring D-fructose consumption during a fermentation process

The colorimetric and fluorometric detection of d-fructose was achieved by employing a two component sensing system composed of an arylboronic acid as the host molecule and a pH sensitive spirocyclic rhodamine dye as the indicator molecule.

KINETIC STUDIES OF SOLVENT AND PRESSURE EFFECTS ON THERMAL ISOMERIZATIONS OF N-PHENYL- AND N-METHYLRHODAMINELACTAMS

Solvent and pressure effects were examined for the isomerization rates of N-phenyl- and N-methylrhodaminelactams (RL-Ph and RL-CH3) from their zwitterionic to the spiro forms.From the pressure dependence of the reaction rate, the activation volumes were estimated to be about 5 cm3mol-1 for RL-Ph and 3-10 cm3mol-1 for RL-CH3.It is proposed that there are two rotameric isomers for the coloured zwitterionic forms, and the role of these rotamers in the kinetic effects of solvent and pressure is discussed.The results are consistent with a reaction mechanism involving heterolytic ring closure on activation.

Anilinomethylrhodamines: PH sensitive probes with tunable photophysical properties by substituent effect

A series of pH dependent rhodamine analogues possessing an anilino-methyl moiety was developed and shown to exhibit a unique photophysical response to pH. These anilinomethylrhodamines (AnMR) maintain a colorless, nonfluorescent spirocyclic structure at high pH. The spirocyclic structures open in mildly acidic conditions and are weakly fluorescent; however, at very low pH, the fluorescence is greatly enhanced. The equilibrium constants of these processes show a linear response to substituent effects, which was demonstrated by the Hammett equation.

Long-Lived Charge-Transfer State Induced by Spin-Orbit Charge Transfer Intersystem Crossing (SOCT-ISC) in a Compact Spiro Electron Donor/Acceptor Dyad

We prepared conceptually novel, fully rigid, spiro compact electron donor (Rhodamine B, lactam form, RB)/acceptor (naphthalimide; NI) orthogonal dyad to attain the long-lived triplet charge-transfer (3CT) state, based on the electron spin control using spin-orbit charge transfer intersystem crossing (SOCT-ISC). Transient absorption (TA) spectra indicate the first charge separation (CS) takes place within 2.5 ps, subsequent SOCT-ISC takes 8 ns to produce the 3NI* state. Then the slow secondary CS (125 ns) gives the long-lived 3CT state (0.94 μs in deaerated n-hexane) with high energy level (ca. 2.12 eV). The cascade photophysical processes of the dyad upon photoexcitation are summarized as 1NI*→1CT→3NI*→3CT. With time-resolved electron paramagnetic resonance (TREPR) spectra, an EEEAAA electron-spin polarization pattern was observed for the naphthalimide-localized triplet state. Our spiro compact dyad structure and the electron spin-control approach is different to previous methods for which invoking transition-metal coordination or chromophores with intrinsic ISC ability is mandatory.

Small-molecule labeling of live cell surfaces for three-dimensional super-resolution microscopy

Precise imaging of the cell surface of fluorescently labeled bacteria requires super-resolution methods because the size-scale of these cells is on the order of the diffraction limit. In this work, we present a photocontrollable small-molecule rhodamine spirolactam emitter suitable for non-toxic and specific labeling of the outer surface of cells for three-dimensional (3D) super-resolution (SR) imaging. Conventional rhodamine spirolactams photoswitch to the emitting form with UV light; however, these wavelengths can damage cells. We extended photoswitching to visible wavelengths >400 nm by iterative synthesis and spectroscopic characterization to optimize the substitution on the spirolactam. Further, an N-hydroxysuccinimide-functionalized derivative enabled covalent labeling of amines on the surface of live Caulobacter crescentus cells. Resulting 3D SR reconstructions of the labeled cell surface reveal uniform and specific sampling with thousands of localizations per cell and excellent localization precision in x, y, and z. The distribution of cell stalk lengths (a sub-diffraction-sized cellular structure) was quantified for a mixed population of cells. Pulse-chase experiments identified sites of cell surface growth. Covalent labeling with the optimized rhodamine spirolactam label provides a general strategy to study the surfaces of living cells with high specificity and resolution down to 10-20 nm.

Study of Rhodamine-Based Fluorescent Probes for Organic Radical Intermediates

Rhodamine-based amide derivatives for the detection of radical intermediates in organic reactions were synthesized and used as fluorescent probes over a wide range of solvents. The mechanistic studies confirm a reversible opening and closing of the spirolactam ring. Compound 21 can be used to support the radical mechanism or in the real-time monitoring of radical intermediates.

Tuning the Photophysical Properties of Spirolactam Rhodamine Photoswitches

Spirolactam rhodamines are fluorescent photoswitches that are useful for single molecule localization microscopy, volumetric 3D digital light photoactivatable dye displays, and other applications. Measurement of the photophysical properties, particularly photoswitching kinetics and quantum yields, is challenging and a comprehensive understanding of how molecular structure affects these parameters remains incomplete. In this study, we have synthesized a series of N-aryl spirolactam rhodamine photoswitches with fluorescent emissions at 585 nm and 518 nm. Extinction coefficients and fluorescence quantum yields of the fluorescent form of the photoswitch have been measured using excess trifluoroacetic acid to drive the equilibrium to the open form. A method to determine photoswitching kinetics and quantum yields was developed by monitoring the kinetics to reach equilibrium between the on-state and off-state and fitting this data to a rate equation for a reaction in equilibrium. Trends based on the electronic and steric properties of the aryl substituents were evaluated. Using this information, a proof-of-principle demonstration of 3D voxel formation was accomplished using a green (518 nm) emitting photoswitch, setting the foundation for a multi-colour volumetric 3D display.

A Multisite-Binding Switchable Fluorescent Probe for Monitoring Mitochondrial ATP Level Fluctuation in Live Cells

Adenosine triphosphate (ATP), commonly produced in mitochondria, is required by almost all the living organisms; thus fluorescent probes for monitoring mitochondrial ATP levels fluctuation are essential and highly desired. Herein, we report a multisite-binding switchable fluorescent probe, ATP-Red 1, which selectively and rapidly responds to intracellular concentrations of ATP. Live-cell imaging indicated that ATP-Red 1 mainly localized to mitochondria with good biocompatibility and membrane penetration. In particular, with the help of ATP-Red 1, we successfully observed not only the decreased mitochondrial ATP levels in the presence of KCN and starvation state, but also the increased mitochondrial ATP levels in the early stage of cell apoptosis. These results indicate that ATP-Red 1 is a useful tool for investigating ATP-relevant biological processes. Illuminating the ATP: A multisite-binding, switchable fluorescent probe can selectively and rapidly respond to ATP at intracellular concentrations. In live-cell imaging, the probe was successfully applied to monitor fluctuations in mitochondrial ATP levels.

Substituent effects on the turn-on kinetics of rhodamine-based fluorescent pH probes

Fluorescent turn-on probes based on a rhodamine spirolactam (RSL) structure have recently become a popular means of detecting pH, metal ions, and other analytes of interest. RSLs are colorless and non-fluorescent until the target analyte induces opening of the spirocyclic ring system, revealing the fully conjugated and highly fluorescent rhodamine dye. Among RSLs opened by acid, we have observed wide variation in the kinetics of the fluorescence turn-on process such that some probes would not be usable in situations where a rapid reading is desired or the pH fluctuates temporally. Herein we present a systematic investigation of the fluorescence turn-on kinetics of RSLs to probe the hypothesis that the reaction rates are influenced by the electronic properties of the spirolactam ring system. A series of 8 aniline-derived RSLs with para substituents ranging from electron-donating to electron-withdrawing was prepared from rhodamine B. The fluorescence turn-on rates are observed to increase by a factor of four as the substituent is tuned from methoxy to nitro. This effect is explained in terms of the destabilization of the reaction intermediate by the substituent. As the reaction rates increase across the series, a concomitant increase in fluorescence intensity is also observed. This result is attributed to an increase in the concentration of the fluorescent form of the dye and is consistent with the expected equilibrium properties of this system. These findings are applied to the design of a faster-reacting and more intensely fluorescent RSL pH probe.