Preparation, NMR studies and crystal structure of mononuclear and dinuclear Pd(II) and Pt(II) complexes that contain 1,2-bis[3-(3,5-dimethyl-1-pyrazolyl)-2-thiapropyl]benzene

The reaction between 1,2-bis[3-(3,5-dimethyl-1-pyrazolyl)-2-thiapropyl]benzene (bddf) and [MCl2(CH3CN)2] (M = Pd(II), Pt(II)) in a 1:1 M/L ratio in CH2Cl2 or acetonitrile solution, respectively, gave the complexes trans-[MCl2(bddf)] (M = Pd(II) (1), Pt(II) (4)), and in a 2:1 M/L ratio led to [M2Cl4(bddf)] (M = Pd(II) (2), Pt(II) (5)). Treatment of 1 and 4 with AgBF4 and NaBPh4, respectively, gave the compounds [Pd(bddf)](BF4)2 (3) and [Pt(bddf)](BPh4)2 (6). When complexes 3 and 6 were heated under reflux in a solution of Et4NBr in CH2Cl2/CH3OH (1:1) for 24 h, analogous complexes to 1 and 4 with bromides instead of chlorides bonded to the metallic centre were obtained. These complexes were characterised by elemental analyses, conductivity measurements, infrared, 1H, 1H{195Pt}, 13C{1H}, 195Pt{1H} NMR, HSQC and NOESY spectroscopies. The X-ray crystal structure of the complex [Pd(bddf)](BF4)2 · H2O has been determined. The metal atom is tetracoordinated by the two azine nitrogen atoms of the pyrazole rings and two thioether groups.

Graphical abstractThe reactivity of 1,2-bis[3-(3,5-dimethyl-1-pyrazolyl)-2-thiapropyl]benzene (bddf) towards Pd(II) and Pt(II) has been tested. The synthesis, characterisation and X-ray crystal structure of [Pd(bddf)](BF4)2 · H2O is reported.Figure optionsDownload full-size imageDownload as PowerPoint slide