M5H5X (M = Ag, Au, Pd, Pt; X = Si, Ge, P, S):  Hydrometal Pentagons with D5h Planar Pentacoordinate Nonmetal Centers

A density functional theory investigation has been presented in this work on M(5)H(5)X hydrometal pentagons (M = Ag, Au, Pd, P) with D(5)(h) planar pentacoordinate nonmetal centers (X = Si, Ge, P, S). The introduction of the nonmetal centers X introduces p aromaticity to M(5)H(5)X complexes. These novel planar complexes are favored in thermodynamics and confirmed to be aromatic in nature. They may be expanded to one, two, or even three dimensions with multiple planar pentacoordinate silicon and other nonmetal centers.