6538 q tof

In this experiment, chromatographic separation was performed using an ACQUITY UPLC HSS T3 column (2.1 × 100 mm I.D., 1.8 μm, Waters, USA). The column was maintained at a temperature of 35 °C, and the mobile phases consisted of water (Phase A) and acetonitrile (Phase B) with the addition of 0.1% formic acid. The gradient program involved the application of a 5% solution of Phase B for the first 3 min, followed by a linear increase from 5 to 95% solution B over the next 12 min (3–15 min), and then maintaining the 95% solution B for an additional 2 min (15–17 min). A 5-minute post-treatment period was conducted with a flow rate of 350 µL/min. The sample injection volume was approximately 2 µL.
The data in this study were collected using Agilent 1290 LC and 6538 Q-TOF mass spectrometers, employing electrospray ionization in both positive and negative ionization modes. The drying gas N2 was delivered at a rate of 9 L/min, while the temperature was maintained at 360 °C. The nebulizer pressure was set at 39 psi, and the capillary voltage was adjusted to 4000 V and 3900 V for positive and negative ionization modes, respectively. The scan range for the mass spectra was set from 50 to 1000 m/z. To ensure accuracy and reproducibility, a reference solution was utilized for real-time correction of the mass spectra, with the lock mass (m/z 922.009798, 121.050873) serving as a reference point.

NMR and HRMS graphs are reported in the supporting information. Where otherwise noted, all chemicals purchased were from a commercial supplier and were used without further purification. The THF solvent used for the synthesis of 1,3-diketones were first dried with a molecular sieve 4 Å and was stored under a nitrogen atmosphere for 72 h before being used. All the reactions were carried out under an inert atmosphere of argon. The progress of the reaction was monitored by TLC analysis. High-resolution mass spectra were recorded with a mass spectrometer (Agilent 6538 Q-TOF with dual ESI source). ¹H and ¹³C NMR spectra were recorded on a Bruker Advance spectrometer [400 MHz (¹H) and 100 MHz (¹³C) in CDCl₃ (first de-acidified by passing it through calcium carbonate before testing) and with DMSO. The solvent peaks were referenced according to the literature^{56 (link)}. UV–visible absorption spectra were recorded on Eppendorf UV–Vis spectrophotometer. The fluorescence spectra were measured on Varian carry fluorescence spectrophotometer. The fluorescence lifetime was determined using Fluoromax-4 fluorimeter (Horiba) in a quartz cuvette (Starna). Excitation was carried out using a 293-nm delta diode (Horiba) in Fluoromax-4C-TCSPC configuration. The diode was pulsed at a 2 MHz repetition rate, the decay was measured until 10,000 counts were reached in the peak channel.