Polymorphism of triphenyl phosphite

The glass-forming liquid triphenyl phosphite (TPP) has recently attracted much attention due to the possible existence of a polyamorphism, i.e., the existence of two or more amorphous phases. In the present work we provide experimental evidence of the existence of a polymorphism in TPP. In addition to the already known conventional crystalline phase, which melts at 299.1 K, it has been found that TPP can crystallize in another polymorphic phase. The new polymorph can be obtained from the liquid phase due to direct cooling from the room temperature up to 245 K where it is held for 15 min and then heated up to 270 K. At 270 K crystallization of the new polymorph occurs, which melts at 291.6 K.