Carbon Sulfide Flowers

Significance

Circulene 3 was synthesized in two steps with an overall yield of 80%. In the first step, an excess of LDA and sulfur leads to replacement of all of 1’s protons with sulfur atoms. After extraction into water and acidification, intermediate 2 is isolated and then subjected to vacuum pyrolysis. Compound 3 sublimes in the temperature range of 450-535 °C, indicating its high thermal stability. Because its empirical formula is an octamer of C₂S, 3 can be considered a new form of carbon sulfide. The authors have named it ”sulflower" because it resembles a sunflower.