Correlation of Structure with Crystalline to Amorphous Phase Transitions of 1,3,6-Substituted Fulvene-Derived Molecular Glasses
作者:Loren C. Brown、Andrew J. Peloquin、Nicholas P. Godman、Gary J. Balaich、Scott T. Iacono
DOI:10.1021/acs.joc.0c01014
日期:2020.9.4
An investigation into the crystalline to amorphous phase transitions of prepared 1,3,6-substituted pentafulvenes showed the expected reversible heated melt and cooling recrystallization in only a few examples. Systematic incorporation of bulky substituents at the 6-position of the fulvene ring led to the nonreversible thermal behavior, rendering phases that were locked into glassy, vitrified states
对制得的1,3,6-取代的五烯丙基戊烯的晶体相向非晶相转变的研究仅在几个实例中显示了预期的可逆加热熔体和冷却重结晶。在富勒烯环的6-位上大体积取代基的系统掺入导致不可逆的热行为,使相被锁定为玻璃态,玻璃化状态。这些分子玻璃具有物理透明性和无定形特征,玻璃化转变温度在61-77°C的范围内,可与高强度塑料(如聚对苯二甲酸乙二醇酯)相媲美。另外,发现熔点转变和所得的熔化热值直接受6-位取代基的性质影响。单晶X射线晶体学表明,在某些情况下,具有稠合芳族化合物的富勒烯表现出高度的分子间π-π堆积。这些结果表明,一类分子玻璃形成剂作为主体材料具有潜在的新型光学应用可调节的整体性质。