7250 gc q tof

A glass microvial containing 3 mg of sample was placed inside the TSP attached to an Agilent 7890B gas chromatograph equipped with a Restek Rxi-5 ms column (30 m × 320 μm × 0.25 μm). The mass spectrometer was an Agilent 7250 GC/Q‑TOF equipped with a low-energy-capable EI source (70 eV). The TSP was set at 300 °C and the oven temperature set at 40 °C for one minute, increasing by 20 °C/minute until 320 °C where it was held for five minutes. Helium was used as a carrier gas, at 1.43L/min flow rate and 8.7psi pressure. The equilibration time was 0.5 min and the sample injection was splitless. The mass range was 50 to 650 m/z. All samples were run in triplicate with blanks added between samples. Data analysis was performed using Agilent Mass Hunter Qualitative Analysis 10.0 with compound assignments using NIST Library 17. Only compounds with a match factor (MF) and reverse match factor (RMF) > 700 and where the molecular ion is present with an accuracy mass error below 50 ppm were shortlisted.

NMR spectra were recorded on a Bruker-600 (Bruker, Germany (600 MHz for ¹H; 151 MHz for ¹³C). ¹H NMR spectra were referenced relative to internal Si(Me)₄ (TMS) at δ 0.00 ppm or CDCl₃ at δ 7.26 ppm. ¹³C NMR spectra were recorded at ambient temperature on Bruker-600 (151 MHz) spectrometers and are referenced relative to CDCl₃ at δ 77.16 ppm. Data for ¹H, ¹³C NMR are recorded as follows: chemical shift (δ, ppm), multiplicity (s = singlet, d = doublet, t = triplet, m = multiplet, q = quartet, quint = quintet, br = broad), integration and coupling constant (Hz). High-resolution mass spectra were recorded on a P-SIMS-Gly produced by Bruker Daltonics Inc. (Bruker, Germany) using electrospray-ionization time of flight (ESI-TOF) and an Agilent Technologies 7250 GCQTOF using EI-TOF (Agilent Technologies, CA, USA). n-Bu₄NBF₄, phenylacetylene and CH₃CN were purchased from Energy Chemical Company and Taitan Chemical Company in China. Other substituted xanthenes and thioxanthenes were synthesized according to the known methods [32 (link),34 (link)].