Metastability is a challenging problem in crystallization, where the metastable phase in a crystalline phase is usually thermodynamically unfavourable and unstable, but kinetically favourable and stable [1]. The aim of this study was to assess synthensized metastable N, N’-bis(4-chlorophenyl)thiourea for its stability status [2-4]. In line with this, N, N’-Dimethylformamide was used in a slow evaporation process. In this process, N, N’-Dimethylformamide formed a cocrystal (C16H17Cl2N3OS) witth N, N’-bis(4-chlorophenyl)thiourea via a network of classical N-H….O to avoid voids. The characterization technique of single X-ray crystallography confirmed the structure of the cocrystal, the ShelXT solution program solved the structure, and the Gauss–Newton 2017/1 version of olex2 refined the structure. The results revealed that C16H17Cl2N3OS (cocrystal) with Mr (370.30) and a crystal size of 0.17 x 0.12 x 0.10 mm appeared as a white crystal in a polygon-like shape in the P21/c monoclinic space group. Additional results revealed cell parameters of a = 92.360 (4) Å, b = 7.2232 (3) Å, c = 25.2555 (11) Å, β = 91.376 (3), α = γ = 90°, V= 1684.40 (12) Å3, T = 119. 94 (13) K, Z = 4, Z’ = 1, and the calculated density (gcm-1). The significance of this study is the application of cocrystals as desolution blockers in active pharmaceutical ingredients (API) and materials science.
References
1. Li, C., Zhang, C., Ren, Y. Growth and morphological control of metastable KDP crystals using defect-free seeds. RSC Advances, 2026, 11, 10012-10021.
2. Odularu, A.T., Ajibade, P. A., Mbese, J. Z., Oyedeji, ,O. O., Puschmann, H. Synthesis and crystal structure of N,N′-bis(4-chlorophenyl)thiourea N,N-dimethylformamide. Open Chemistry,. 2021, 19, 511– 517.
3. Jambi, SMS. Characterization and synthesis of novel thiourea derivatives. International Journal of Chemical and Technology Research, 2019, 12, 177–87.
4. Das, C, Zhang H, Li, R, Zou H. Synthesis and characterization of thiourea. Polish Journal of Chemical Technoology, 2019,. 1, 35–39.
