The substitution of a chloro ligand in (IPr)Ag–Cl with aliphatic and aromatic phosphine ligands, PPh3, PCy3, PPh2Py, dppf, dppm, and dppe, was investigated. Unlike gold(I) complexes, the heteroleptic complexes, (IPr)Ag-PR3+, are less stable in the solution phase. The order of mixing reactants, solvent type, and reaction time plays crucial roles in obtaining the desired product. In a methanolic solution, the generated (IPr)Ag(I)+ ions from (IPr)Ag–Cl are less stable compared with (IPr)Au(I)+ and only PCy3 and PPh2Py stabilize this cationic fragment in solution. In the single-crystal X-ray diffraction analysis of complexes 1 and 2, the Ag(I) centers exhibited a linear geometry. Other forms of silver(I) complexes containing only phosphine ligands were also formed in a solution containing the (IPr)Ag–Cl precursor. Computational analysis of the complexes using density functional methods provided insights into the nature of electronic transitions, noncovalent interactions, and fragmental bonding contributions.
Neshat et al. (Thu,) studied this question.