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- I -pyrazolyl)-2-thiapropyl]benzene (bddf) and [MC12(CH3CN)2] (M = Pd(ll), Pt(ll)) in a 1: 1 M/L ratio in CH2Cl2 or acetonitrile solution, respectively, gave the complexes trans-MCI2(bddf)] (M = Pd(II) (1), Pt(il) (4)), and in a 2:1 M/L ratio led to [M2Cl4(bddf] (M = Pd(II) (2), Pt(II) (5)). Treatment of I 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 CH,CH2Cl2/CH3OH (1: 1) for 24 h, analogous complexes to I and 4 with bromides instead of chlorides bonded to the metallic centre were obtained. These complexes were characterised by elemental analyses, conductivity measurements, infrared, H-1, H-1{ 115pt I, C-13 H-1), Pt-195(H-1) 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. (c) 2007 Elsevier Ltd. All rights reserved.