This is an answer I gave 11 days ago for a question: How to dissolve PdCl2? "In diluted aqueous HCl solution for example, making H+2[PdCl4]2-. The latter anion can also be made by adding NaCl or LiCl to PdCl2 suspension in alcohol or water. Other catalyst precursors such as Pd(CH3CN)2Cl2, Pd(C6H5-CN)2Cl2, Pd(COD)Cl2 etc. can also be made by adding the respective weak ligand in excess to the alcohol suspension of PdCl2, followed by gentle heating with stirring." The above mentioned catalysts precursors can be used for making PdCl2 complexes with various ligands.
Make the Pt(DMSO)2Cl2 complex first, its easy to make just put PtCl2 into DMSO and you get the complex out as long needles almost immediately. You can collect them via filtration. Then react this complex with your ligand. The ligated DMSO will be replaced first.