Figure 13
Summary of structures of squarate 4,4′-bipyridinium salts including a yellow P21/n form (CSD refcode HAZFAP01; Martins et al., 2009) at ambient conditions, a high-voltage red-shifted yellow P21/n form and a high-temperature/pressure red C2/c form (CSD refcode HAZFAP07; Martins et al., 2009). |