*2.1. General Details*

All reagents and solvents were purchased from standard commercial suppliers and used as received, except for 9,10-dimethyl-9,10-dihydro-2,3,6,7-tetracrboxyl-9,10-ethanoanthracene, which was synthesised according to a literature preparation [51]. NMR spectra were obtained using a Bruker Avance 400 spectrometer operating at 400 MHz (1H) or 100 MHz (13C). FT–IR spectra were collected using an Agilent Carey 630 diamond attenuated total reflectance spectrometer. Mass spectra were collected using a Micromass platform electrospray mass spectrometer. TGA data were collected using a Mettler TGA/DSC 1 instrument (5 K/min under N2 atmosphere). Elemental analyses were conducted at the London Metropolitan University.
