Solid-State Structures of Platinum-Sulfur-Nitrogen Stacking Compounds: (Pt(S2N2)(PMe2Ph)2), (Pt(S2N2H)(PMe2Ph)2)Cl, (Pt(S2N2H)(PMe2Ph)2)PF6, and (Pd(S2N2H)(PMe2Ph)2)BF4.