Journal of Molecular Structure 1270 (2022) 133985 Contents lists available at ScienceDirect Journal of Molecular Structure journal homepage: www.elsevier.com/locate/molstr Synthesis, characterization, and x-ray crystallography of unexpected chloro-substitution on 1-(4-chlorophenyl)-3-phenylthiourea platinum(II) complex with tertiary phosphine ligand Ahmed S. Faihan a,∗ , Nazk Mohammed Aziz b , Muhammad Ashfaq c , Walid M.I. Hassan d,e , Subhi A. Al-Jibori a , Ahmed S. Al-Janabi a , Muhammad Nawaz Tahir c , Alyaa S.M.O. Al-barwari f a Department of Chemistry, College of Science, Chemistry Tikrit University, Tikrit, Iraq b Department of Chemistry, College of Science, University of Sulaimani, KRG, Iraq c Department of Physics - University of Sargodha, Punjab, Pakistan d Chemistry Department, Faculty of Science, King AbdulazizUniversity, B.O. 80203, Jeddah 21589, Saudi Arabia e Chemistry Department, Faculty of Science, Cairo University, Giza 12613, Egypt f Department of Chemistry, College of Education for Pure Science, University of Mosul, Iraq a r t i c l e i n f o Article history: Received 29 May 2022 Revised 16 August 2022 Accepted 18 August 2022 Available online xxx Keywords: Thiourea Thiourea DIanion 1-(4-chlorophenyl)-3-phenylthiourea Crystal packing environment Quantum calculations a b s t r a c t The reaction of 1-(4-chlorophenyl)-3-phenylthiourea (CPTH 2 ) with [PtCl 2 (PPh 3 ) 2 ] moiety in a 1:1 molar ratio in a basic solution afforded unexpected Pt(II) thiourea dianion complex. The crystal structure re- vealed that the second phenyl ring of the parent ligand was substituted with a chlorine atom. Chlorine substitution on the phenyl ring might have been aided by the solvent CH 2 Cl 2 . The crystal structure re- vealed a platinum(II)-centered four-membered ring structure. FT-IR, 1 H-NMR, and 31 P-NMR spectroscopy were also utilized to study the complex. The crystal packing environment is explored by Hirshfeld surface analysis, enrichment ratio calculations and void analysis. Various quantum calculations were performed on both the ligand and its complex, and the calculated values were compared to the experimental ones. The energies of the two resonance structures of the CPTH 2 ligand are very close. However, the stability of the thione form was slightly greater than that of the thiol form. The bond lengths and bond angles calculated by Orca for the Pt(II) complex were nearly identical to the experimental values. The biological assessment of the Pt(II) complex was evaluated against four pathogenic bacteria: Pseudomonas aerugi- nosa, Staphylococcus aureus, Escherichia coli, and Salmonella typhi (S. typhi). The Pt(II) complex exhibited moderate inhibition values against all bacterial species, with the exception of Pseudomonas aeruginosa (P. aeruginosa), which exhibited the greatest activity. © 2022 Elsevier B.V. All rights reserved. 1. Introduction In the past 50 years, ligands with sulfur or nitrogen donor atoms have demonstrated notable antibacterial and anticancer ac- tivity because of their unique coordination behaviors [1,2]. Ad- ditionally, the catalytic activity of mixed ligand complexes com- prising P donor ligands has been observed [3,4]. Heterocyclic lig- ands, in particular thioureas, have received more attention as a re- sult of their ability to produce various coordination modes with heavy metal ions [5–7]. Thioureas have been shown to have the following recognized coordination modes: mono-dentate neutral mode, mono-dentate anionic mode, bidentate-mono-anion mode, ∗ Corresponding author. E-mail address: a-s.fehan@tu.edu.iq (A.S. Faihan). and bidentate-dianion mode [8]. On the other hand, the latter type of complex is relatively uncommon [9] (Fig. 1). In the literature, there have been reports of thiourea dian- ion complexes with peculiar geometries. One product is produced when thiourea is symmetric, that is, when both of the substituents on the thiouredio molecule are the same [10]. Two isomers are formed when different groups are linked to the thiouredio: the proximal isomer and distal isomer (Fig. 2). The quantitative rela- tionship between the two isomers is affected by the type of sub- stituents [11]. In a recent work, Spenceley et. al. showed how al- tering substituents could affect the coordination mode of the re- sulting complexes [11]. Allowed substituents were solely electron- rich groups. We aimed to extend on this work by employing an electron-withdrawing substituent. The anionic intermediate could be stable if the substitutes are withdrawing groups. There should https://doi.org/10.1016/j.molstruc.2022.133985 0022-2860/© 2022 Elsevier B.V. All rights reserved.