Synthesis, characterization, single crystal XRD and biological screenings of organotin(IV) derivatives with 4-(2-hydroxyethyl)piperazine-1-carbodithioic acid

Abstract

Organotin(IV) thiocarboxylates R₂SnL₂ (R = Me: 1: Ph: 2)/R₂(Cl)SnL (R = n-Bu: 3; Ph: 4)/R₃SnL (R = Me: 5; n-Bu: 6; Ph: 7), where L = 4-(2-hydroxyethyl)piperazine-1-carbodithioate, have been synthesized by stirring together 1,2-hydroxyethylpiperazine and CS₂ in methanol, and then refluxing with a di-/triorganotin chloride. The synthesized products have been characterized by various spectroscopic (IR, ¹H NMR, ¹³C NMR, EI-MS) techniques and single crystal XRD. FT-IR data indicate bidentate binding of the ligand. The magnitude of ²J(¹¹⁹Sn–¹H) demonstrated a skew trapezoidal environment around tin(IV) in 1, whereas the metal geometry in 5 was between distorted tetrahedral and trigonal bipyramidal in solution. ¹³C NMR revealed four- and five-coordinate environments in 6 and 7, respectively, in non-coordinating solvent. EI-MS data agreed very well with the structural skeleton of the products. Single crystal XRD study has shown skew trapezoidal- and trigonal-bipyramidal Sn(IV) in 1 and 7, respectively. Compound 6 interacted with salmon sperm DNA (SS-DNA) with significant hypochromic effect and an intercalating mode of binding. Diorganotin(IV) derivatives (2 and 3) generally exhibited poor antibacterial/antifungal potential as compared to their trialkyltin(IV)/triaryltin(IV) counterparts (5 and 6). The in vitro hemolytic activities show that average lysis of human red blood cells caused by 1–7 was significantly lower compared to triton X-100 (positive control, 100% lysis) and not very much higher than PBS (negative control, 0% lysis).

Keywords:

• Organotin(IV)
• 4-(2-hydroxyethyl)piperazine-1-carbodithioate
• spectroscopic
• XRD
• salmon sperm DNA
• antibacterial/antifungal
• hemolytic

Acknowledgment

SH thanks the HEC, Islamabad, Pakistan, for financial support under the PhD Fellowship Scheme Batch-IV (PIN Code: 074-3160-Ps4-362).

Disclosure statement

No potential conflict of interest was reported by the authors.