Solvent-Free Synthesis, Crystal Structure and Molecular Docking of N-(2-Hydroxyethyl) Piperazinum Chloride with Selected Biological Proteins

The ionic compound N-(2-hydroxyethyl)piperazinium chloride (HEPH)Cl, containing a piperazinium cation with a + 1 charge, was crystallized in the orthorhombic space group P2₁2₁2₁. The unit cell parameters were determined to be a = 8.6083(3) Å, b = 8.8523(3) Å, and c = 10.7405(4) Å. The volume of the unit cell was found to be 818.46(5) ų, with a Z value of 4. Refinement yielded R[F² > 2σ(F²)] = 0.018, wR(F²) = 0.028, and a goodness-of-fit parameter of S = 1.77. The crystal structure reveals the presence of three hydrogen bonds: O1–H1o1···Cl1, N1–H1n1···N2, and N1–H2n1···Cl1, which contribute to the specific molecular arrangements within the crystal lattice.Electrochemical properties of (HEPH)Cl were examined by cyclic voltammetry (CV). Molecular docking experiments were conducted to assess the interactions of (HEPH)Cl with Mycobacterium tuberculosis DNA gyrase, coronavirus main protease, Plasmodium falciparum protein, and human serum albumin.

N-(2-hydroxyethyl)piperazinium chloride cation uniquely adopts a chair conformation carrying a +1 charge, stabilized by crucial hydrogen bonding interactions that enhance molecular recognition and binding affinity observed in docking study.