C MAS NMR spectra were recorded on Avance Neo 400 MHz spectrometer (Bruker) equipped with a 4 mm CP-MAS probe with 1 H- F and 31 P- N coils. The sample rotation frequency was 10 kHz and the relaxation delay was set to 5s. Chemical shifts are given in ppm relative to the tetramethyl silane (SiMe4) standard. FT-IR spectroscopy was recorded on IFS66/S (Bruker) using KBr pellets in the wavelength range of 600-4000 cm -1 . Mass spectrometry measurements were recorded on UltrafleXtreme MALDI-TOF (Bruker Daltonik) mass spectrometers. The samples were first mixed with the matrix dithranol in an agate mortar. The solid mixture was then transferred to the MALDI plate using a spatula and the reflective positive ion mode was used to acquire the mass spectra. Calibration was performed externally using a poly(methyl methacrylate) standard (MALDI validation set PMMA, Fluka Analytical).