Cold Crystallization of Ferrocene-Hinged π-Conjugated Molecule Induced by the Limited Conformational Freedom of Ferrocene

• DOI: 10.1021/acs.jpcb.9b06880
• Publication Date: 2019-09-09T22:53:55Z
• Authors: Yuki Tsujimoto; Tsuneaki Sakurai; Yuichiro Ono; Shusaku Nagano; Shu Seki
• Keywords: Supercooling

Crystallization that proceeds above the glass transition temperature upon heating glassy or amorphous state is referred to as "cold crystallization", which has often been observed in supercooled phases of molecular materials followed by thermodynamically stable crystalline phase. Although this behavior common for macromolecules with high structural flexibility among segments preserving wide range corresponding phases, cold crystallization small molecules relatively rare and there still less knowledge on design guideline such molecules. Here we report a ferrocene-hinged molecule DC12 carrying two units didodecyl-substituted pentathiophenes at 1,1'-positions. Due rotational freedom ferrocene unit, forms solid cooling from its isotropic melt. The was realized even slow 0.1 °C min-1. possible reason easy formation phase coexistence various conformations originating open conformers ferrocene. On phase, shows estimated activation energy 61 kJ mol-1. composed closed form packed lamellar fashion, degree crystallinity remarkably compared case macromolecular materials. triggered intermolecular interactions dodecyl chains unit. This work provides an unprecedented example ferrocenes act heat-controllable hinges condensed phases. Considering phenomenon related heat-storage materials, strategy presented will be novel realize both easily formed highly through crystallization.