Microwave-assisted synthesis, crystal structures and DFT calculations of two novel silver(І) dimers [Ag2(μ-X)2(μ-dppm)(PPh3)2] (X = Br, I) with butterfly-shaped dinuclear cores

Reactions of Ag4X4(Ph3P)4 (X = Br, I) with 1,3-bis(diphenylphosphine)methane (dppm) ligand under microwave heating conditions afforded two asymmetric silver(I) dimers of the type [Ag2(μ-X)2(μ-dppm)(PPh3)2], X = Br(1), I(2), with butterfly-shaped dinuclear cores. The molecular structures of two compounds have been established by single-crystal X-ray diffraction and satisfactorily calculated by using the PW91 functional considered with the DNP basis set and ECP.