The C NMR spectra were recorded at several spectrometers with resonance frequencies ranging from 15 MHz to 100 MHz and a resolution ranging from 0.025 to 0.045 ppm. Spectra were acquired using a pulse flip angle of 22.5 – 45 degrees and a pulse repetition time of 4 – 7 seconds. Samples were prepared by dissolution in CDCl, DO, or DMSO-d. Each spectrum is accompanied by a list of the observed peaks with their respective chemical shifts in ppm and their intensities. Most spectra show the peak assignment. This collection contains ca 14,200 spectra and is being updated.