Factors Affecting the Stability of Platinum(II) Complexes with 1,2,4-Triazolo[1,5- a]pyrimidine Derivatives and Tetrahydrothiophene-1-Oxide or Diphenyl Sulfoxide

Abstract

The platinum(II) complexes of general formula [PtCl₂(dstp)(S-donor)] were dstp 5,7-dimethyl-1,2,4-triazolo[1,5-a]-pyrimidine (dmtp), 5,7-ditertbutyl-1,2,4-triazolo[1,5-a]pyrimidine (dbtp), 5-methyl-7-isobutyl-1,2,4-triazolo[1,5-a]pyrimidine (ibmtp) or 5,7-diphenyl-1,2,4-triazolo[1,5-a]pyrimidine (dptp), whereas S-tetrahydrothio-phene-1-oxide (TMSO) or diphenyl sulfoxide (DPSO) were synthesized in a one-pot reaction. Here, we present experimental data (¹H, ¹³C, ¹⁵N, ¹⁹⁵Pt NMR, IR, X-ray) combined with density functional theory (DFT) computations to support and characterize structure-spectra relationships and determine the geometry of dichloride platinum(II) complexes with selected triazolopyrimidines and sulfoxides. Based on the experimental and theoretical data, factors affecting the stability of platinum(II) complexes have been determined.

Keywords: DFT; NMR; cis-/trans isomers; platinum(II) complex; triazolopyrimidine.