Figure 5. The ternary phase diagram caffeine-maleic acid-
-acetone at 25 C in mass%. (1) liquidus, (2) caffeine þ liquid,
(3) caffeine þ 1:1 cocrystal þ liquid, (4) 1:1 cocrystal þ liquid, (5)
maleic acid þ 1:1 cocrystal þ liquid, (6) maleic acid þ liquid. The
hatched region describes the approximate zone in which the metastable
2:1 cocrystal appears. The data points for this figure are
provided in the Supporting Information.