Polymorphisms Of N,N,N’,N’-Tetrabenzylethane-1,2- Diamine And Reversible Phase Transition Of Its Salts

Polymorphism, the ability of a compound to exist in more than one crystalline form, is becoming increasingly valuable in the sense that polymorphs can offer a unique opportunity to study the structure-property relationships of the same compound formed in different environments. Studies concerning polymorphism are vital for development of any solid material, especially in the pharmaceutical industry, whether single-component or multi-component (cocrystals), have particularly given extensive studies in recent years. The pharmaceutical importance of this phenomenon lies in the fact that different polymorphic phases exhibit unique physicochemical properties and thus have the potential to alter the performance of a solid-state formulation, such as bioavailablity, solid-state stability, and compaction behavior.N-bidentate ligands (N,N,N’,N’-Tetrabenzyl-naphthalene-1,5-diamine, L) was designed and synthesised in this paper. The polymorphs of phase 1,phase 2 and phase 3 of L were prepared. The structures of phase 1 and phase 2 for ligand L are extended into a 2D layered network, but the phase 3 is extended into a 3D structure. Phase 3 is more Stability than phase 1/2 in the Solid state, but it in the opposite in the mother liquor. The different phase will be transformed into each other. Phase 1 will be transform into phase 2 at room temperature liquid,but phase 3 in the boiled liquid. Phase2 will be transform into phase 1 at room temperature liquid,but phase 3 in the boiled liquid. Phase 3 will be transform into the concomitant of phase 1/2 at room temperature liquid.A new co-crystal salts EtOHc[L]-2[H]+·[CuCl4]2-(1) was formed by self-assembly through N-H…Cl between protonated L and metal complexes [CuCl4]2-.At the same time the different phase of co-crystal salts was obtained in different temperature. The different phase will be transformed into each other at different temperature. At low temperature,the crystal changes from P-1 space group into P21/n space group. When the temperature come back into room temperature the crystal changes from P21/n space group into P-1 space group.