Xtalab synergy s diffractometer

Single crystals of α-, β- and γ-VMN were synthesized by the melt microdroplet method using a Linkam hot stage (THM S600, UK) combined with a Nikon POM (Nikon eclipse lv100N pol, China). The commercial VMN powder, purchased from ChemShuttle (Jiangsu, China), was first melted at 274 °C for a few seconds and then cooled to 265 °C. Once an α-VMN nucleus appeared, the melt droplet was immediately heated to 268 °C to let it grow and consume the melt. For β- and γ-VMN, concomitant seeds of α-, β-, and γ-VMN were prepared by crystallizing VMN supercooled liquid at 170 °C. β- and γ-VMN seeds were then introduced into melt microdroplets at 245 and 215 °C, respectively. The polycrystalline seeds were partially melted at 255 °C (for β-VMN) and 224 °C (for γ-VMN) to yield a single nucleus for each polymorph, which were then harvested at 252 °C (for β-VMN) and 215 °C (for γ-VMN) to yield single crystals. SCXRD data were collected on an XtaLAB Synergy-S diffractometer (Rigaku, Poland) using Cu Kα radiation (λ = 1.54184 Å). Cell refinement and data reduction were carried out by CrysAlisPro 171.40.39⁷² . The crystal structures were solved using SHELXT^{63 (link)} and refined using SHELXL^{64 (link)} through the Olex 2-1.3 interface. The simulated PXRD patterns and RMSD₁₅ values were calculated by Mercury software (version 2020.3.0).

IR spectra were measured using a Bruker Tensor 27 FT-IR spectrometer (ATR). UV-Vis measurements were performed in DCM using a Cary 4000 UV-Vis Agilent Technologies spectrophotometer. Fluorescence measurements were performed in DCM using a lifetime and steady-state spectrometer-FLSP 920, Edinburgh Instruments. Regarding the NMR spectra, these were measured in chloroform-d1 or DMSO-d6 using a Bruker Advance spectrometer operating at 500 MHz for ¹H and 125 MHz for ¹³C. As usual, the chemical shifts are reported as δ ppm values, and the residual solvent peaks were used as the internal reference. A Varian 310—MS LC/MS/MS triple quadrupole mass spectrometer fitted with an electrospray–ionisation interface (ESI) was used for the MS spectra. The ESR spectrum was recorded on a Jes-FA 100 Jeol Instrument. For the X-ray diffraction measurements for compound 3 employed a Rigaku XtaLAB Synergy-S diffractometer operating with an Mo-K (λ = 0.71073 Å) micro-focus sealed X-ray tube. The structure was solved using direct methods and refined by full-matrix least-squares techniques based on F². The non-H atoms were refined with anisotropic displacement parameters. The SHELX-2018 crystallographic software package was used for calculations. The crystallographic data summary and the structure refinement for compound 3 are given in Table 3. CCDC reference number: 2280342.