Ascend 400 ft nmr spectrometer

Optical rotations were measured on a JASCO-1020 polarimeter. Electronic Circular Dichroism (ECD) was recorded on a JASCO J-810 spectropolarimeter. UV spectra were collected on a Shimadzu UV 1800 spectrophotometer. IR spectra were recorded in the ATR mode using a PerkinElmer FT-IR Spectrum 400 spectrophotometer. ¹H and ¹³C NMR spectra were recorded on a Bruker ASCEND 400 FT-NMR spectrometer, operating at 400 MHz (¹H) and 100 (¹³C) MHz. HR-ESI-TOF-MS spectra were measured with a Bruker micrOTOF-QII mass spectrometer. Unless otherwise indicated, column chromatography was carried out using Merck silica gel 60 (particle sizes less than 0.063 mm) and GE Healthcare Sephadex LH-20. For thin-layer chromatography (TLC), Merck pre-coated silica gel 60 F₂₅₄ plates were used. Spots on TLC were detected under UV light and by spraying with anisaldehyde-H₂SO₄ reagent followed by heating.

All the reagents and solvents
used for the syntheses were used as received from the commercial suppliers.
The Schiff-base ligand H₂L was synthesized following the
reported procedure.^{64 (link)} TPPO was synthesized
starting from triphenylphosphine following the reported procedure.^{65 (link)} Syntheses and manipulations of samples for all
the experiments were carried out under aerobic conditions. All the
spectroscopy studies were carried out at ambient conditions. UV–vis
spectral studies were carried out on μ(M) ethanol solutions
of the complexes using an Agilent Hewlett-Packard 8453 diode array
UV–Vis spectrometer. The ¹H and ³¹P NMR
spectral studies were carried out for the Y analogues of the complexes
in deuterated solvents (CDCl3 for 1·Y and CD3OD
for 2·Y) chloroform with a Bruker model Ascend 400
FT-NMR spectrometer. Fourier transform infrared (FT-IR) spectroscopy
studies were performed on the thin layers of neat samples with a Bruker-Alpha
Eco-ATR FT-IR spectrometer. Elemental analyses were performed on the
polycrystalline solid samples of the complexes with a Perkin–Elmer
2400 series II instrument.