The interaction between [Pt(µ-Cl)(Safrole-1H)]2 and 1,3-diisopropylbenzimidazolium bromide in the presence of Ag2O

Abstract

The interaction of the dimeric complex [Pt(µ-Cl)(Saf)]2 (1) (Saf: deprotonated safrole) with the salt i Pr2-bimy•HBr in the presence of Ag2O in acetone solvent was studied. The obtained products were mixed complexes of [PtCl(Saf)(i Pr2-bimy)] (2) and [PtBr(Saf)(i Pr2- bimy)] (3) with different molar ratio (PI , PII, PIII) depending on the used molar ratio of 1:salt:Ag2O. In the case of this ratio being 1 : 2 : 1.1, PI was obtained, which is a mixture of 2 and 3 at a 3 : 1 ratio. When concentration of the salt was increased, the product was PII with the molar ratio of 2 : 3 at 1 : 3. However, when both the salt and Ag2O were increased at the same time, 2 and 3 in PIII had equal molar proportions. The two main factors affecting the 2 : 3 molar ratio are the different solubility of AgCl and AgBr, and the different coordinating ability of Cl and Br ligands. The structures of 2 and 3 were determined by 1H NMR spectra and single crystal X-ray diffraction. The results reveal that Saf in 2 and 3 coordinates with Pt(II) via C=Colefinic and C5 of benzene ring. Meanwhile, i Pr2-bimy coordinates with Pt(II) through CNCN and is in trans position compared to the C=Colefinic bond.