From green algae to calcium inside buckyballs

Coorongite and carbonaceous residues from coorongite pyrolysis at 450 and 500°C were studied by laser ablation Fourier transform mass spectrometry. Raw coorongite gave positive‐ion spectra having mainly protonated species of m/z 80–300 when laser ablated with a high laser power density. Endohedral fullerene positive ions of calcium were observed during the laser ablation of coorongite pyrolysis residues. Pyrolysis of the raw coorongite at 450 and 500°C produced residues which on laser ablation using the fundamental frequency of an Nd: YAG laser (1064 nm) gave a series of calcium fullerides. These ions were observed using low laser power densities (100–600 kW cm –2 ) Mixing the coorongite pyrolysis residue with barium sulphate gave M@C n + ions The symbol ‘@’, as in Ca@ 60 , is used to represent an endohedral complex, i.e. the adduct is located inside the carbon cage. where M = calcium or barium. Mixing the coorongite pyrolysis residue with strontium oxalate also gave M@C n + ions where M = calcium or strontium. No ions containing two or more metals were detected.