Figure 1.

(a) Structure of CPA and (b) molecular conformations for the previously reported ambient forms of CPA: α (black), β (gold), γ (blue), δ (purple), and ε (red). The conformations of the propyl group in the α- and β-forms are typical of the Anti-L and Syn-L conformations.²⁴ (c) Representation of sulfonyl urea tape-like H-bonding present in all forms with bifurcated interaction to urea and sulfonyl group. (d) CPA molecules can hydrogen bond in an orientation that resembles a “Z” or “π”.