Inova 400 mhz nmr spectrometer

A Varian Inova 500 MHz NMR spectrometer (11.7 T) equipped with FTS Systems TC-84 Kinetics Air Jet Temperature Controller was used to collect ¹H NMR spectra. ¹³C NMR spectra were acquired using a Varian Mercury 300 MHz or 400 MHz NMR spectrometer. Proton relaxivity experiments were performed at 1.4 T (34 °C) on a Nananalysis NMR spectrometer, at 4.7 T (37 °C) on a Bruker preclinical MRI scanner or at 9.4 T, (37 °C) on a Varian Inova 400 MHz NMR spectrometer. Z-spectra were collected on a Varian Inova 500 MHz NMR spectrometer (11.7 T). All pH measurements were made by utilizing an Orion 8115BNUWP Ross Ultra Semi Micro pH electrode connected to a 702 SM Titrino pH. ThermoFinnigan LCQ Advantage IonTrap LC/MS equipped with a Surveyor HPLC system was used to for mass spectrometry data of the complexes. Iron concentration was determined by using a Thermo X-Series 2 ICP-MS as reported.^{42 , 47 (link)}

All reagents were purchased without further purification unless otherwise noted. Reactions were monitored using thin-layer chromatography (TLC) on commercial silica gel plates (GF254). Visualization of the developed plates was performed under UV light (254 nm). Flash column chromatography was performed on silica gel (200–300 mesh). ¹H and ¹³C NMR spectra were recorded on a Varian INOVA 400 MHz NMR spectrometer at 25 °C. Chemical shifts (δ) are reported in ppm referenced to an internal tetramethylsilane standard, or the DMSO-d₆ residual peak (δ 2.50) for ¹H NMR. Chemical shifts of ¹³C NMR are reported relative to CDCl₃ (δ 77.0) or DMSO-d₆ (δ 39.5). The following abbreviations were used to describe peak splitting patterns when appropriate: br s = broad singlet, s = singlet, d = doublet, t = triplet, q = quartet, m = multiplet. Coupling constants, J, were reported in Hertz unit (Hz). High-resolution mass spectra (HRMS) were obtained on a JEOL AccuTOF with ESI/APCI ion sources coupled to an Agilent 1100 HPLC system. HPLC analysis was performed on a Agilent 1100 series (DAD detector) fitted with a C-18 reversed-phase column (XTerra RP 18, 5 μM, 4.6 × 250mm) with a flow rate of 0.8 mL/min using CH₃CN-H₂O mobile phase and detected under 254 nm UV light. The purity of final products is >95%. Compounds 7CC5 and 7CC5–14 were purchased from Maybridge and Vitas, respectively.