Fig. 3.

Thermally-induced reversible transformations between MSC-311 and MSC-322. In situ time-resolved optical absorption spectra collected from one sample (9.4 mg) in toluene (3 mL) at the two indicated temperatures. When the MSC-311 dispersion was kept at 46 °C (for 788 min), a MSC-311⇒MSC-322 transformation took place (a). When the dispersion was maintained at 15 °C (for 1410 min), MSC-322 slowly transferred back into MSC-311 (b). After the dispersion was again returned to 46 °C (for 538 min), the MSC-311⇒MSC-322 transformation was detected once again (c). When the dispersion was cooled to 15 °C (for 2490 min), MSC-322 transformed into MSC-311 again, slowly (d). The time interval for data collection was 4 min (a), 30 min (b), 2 min (c), and 30 min (d). The presence of isosbestic points suggests that the MSC-311⇔MSC-322 transformation is an interconversion. The thermally-induced transformations between MSC-311 and MSC-322 are reversible