Searching for Unknown Polymorphs by “Quenched Nucleation”: Studies on the Polymorphism of <i>N</i>-(1-Naphthyl) Succinimide

On the basis of the frustration of a fast cooling melt, a “quenched nucleation” protocol has been developed and compared with the conventional homogeneous nucleation procedure in preparation of the single crystal of N-(1-naphthyl) succinimide (NaS) in solution. The results showed that a single crystal with the lowest triclinic symmetry was grown from the quenched nucleation system while an orthorhombic single crystal was obtained from the homogeneous nucleation procedure. The mechanism of the quenched nucleation is speculated by a proposed kinetic model of “waked nuclei”, which may provide a powerful method for exploring the unknown polymorphs.