Alpha 2 ft ir spectrometer

Optical rotation measurements were made on a Rudolph research analytical AUTOPOL IV automatic polarimeter (Rudolph Research Analytical, Hackettstown, NJ, USA), IR spectra were recorded with a Bruker ALPHA II FT-IR spectrometer (Bruker, Billerica, MA, USA), and UV spectra were measured with a Thermo Scientific Nanodrop 2000C spectrophotometer (Thermo Fisher Scientific, Waltham, MA, USA). The ECD spectrum was obtained on a JASCO J-1500 circular dichroism spectrometer (Jasco, Easton, MD, USA). High-performance liquid chromatography (HPLC) was performed using a Varian ProStar 215 solvent delivery module equipped with a Varian ProStar 320 UV-Vis detector (Agilent Technologies, Santa Clara, CA, USA), operating under Star 6.41 chromatography workstation software (Agilent Technologies, Santa Clara, CA, USA). NMR spectra were obtained with a Bruker Avance III NMR spectrometer (Bruker, Billerica, MA, USA) equipped with a 3 mm cryogenic probe and operating at 600 MHz for ¹H and 150 MHz for ¹³C. Spectra were calibrated to residual solvent signals at δ_H 2.50 and δ_C 39.5 in DMSO-d₆. All 2D-NMR experiments were acquired with nonuniform sampling (NUS) set to 50% or 25%. HRESIMS data were acquired on an Agilent Technologies 6530 Accurate-Mass Q-TOF LC/MS instrument (Agilent Technologies, Santa Clara, CA, USA).

NMR spectra were recorded
on Bruker 300 or 400 MHz spectrometers. ¹H and ¹³C chemical shifts are reported in ppm relative to tetramethylsilane
using residual solvent as an internal standard. ¹⁹F chemical
shifts are reported in ppm relative to 5% v/v internal PhF.^{28 (link)} Solution-phase effective magnetic moments were
determined by the method described by Evans^{29 (link)} and are corrected for diamagnetic contributions (as are SQUID magnetometry
data).^{30 (link)} Mass spectrometry data were collected
on a Bruker MicroTOF II with an ESI source. FTIR spectra were recorded
on solid samples using a Bruker Alpha II FTIR spectrometer operating
at 4 cm^–1 resolution. Elemental analyses were performed
by Midwest Microlab. EPR spectra were recorded on a Bruker EMX spectrometer.
Simulations were performed using EasySpin^{31 (link)} (5.2.33) in MATLAB (R2021b). DC magnetic susceptibility data for
a microcrystalline sample of 4 were collected on an MPMS
SQUID magnetometer in the range of 5–300 K with a 10,000 Oe
applied field. The sample was prepared by compressing 12.2 mg of 4 between wads of quartz wool in a length of quartz tubing,
which was then flame-sealed under vacuum. Simulations were performed
using PHI^{32 (link)} (3.1.5).

NMR spectra were recorded
on a Bruker 300 MHz spectrometer. ¹H and ¹³C
chemical shifts are reported in parts per million (ppm) relative to
tetramethylsilane using residual solvent as an internal standard. ¹⁹F chemical shifts are reported in ppm relative to 5% v/v
internal PhF.^{33 (link)} Solution-phase effective
magnetic moments were determined by the method described by Evans^{34 (link)} and are corrected for diamagnetic contributions.^{35 (link)} Mass spectrometry data were collected on a Bruker
micrOTOF II instrument with an ESI source. FTIR spectra were recorded
on solid samples using a Bruker Alpha II FTIR spectrometer operating
at 4 cm^–1 resolution.

The FTIR spectra of CQD thin film before and after exposure to DA solution was recorded in the range of 400–4000 cm⁻¹ using a Bruker ALPHA II FTIR Spectrometer in ATR mode. The Bruker AFM multimode 8 in Scan Asyst mode was used in the range of 2 × 2 μm for topographic imaging of all thin films and to analyze the roughness changes of CQD film after DA adsorption on its surfaces.