A sandwich-type cluster containing Ge@Pd₃ planar fragment flanked by aromatic nonagermanide caps

Area of Science:

• Inorganic Chemistry
• Materials Science
• Supramolecular Chemistry

Background:

• Sandwich-type clusters with planar heterometallic fragments are challenging to synthesize.
• Previous research has not successfully isolated such structures with specific bonding arrangements.

Purpose of the Study:

• To synthesize and characterize a novel sandwich cluster containing a heterometallic planar fragment.
• To investigate the unique bonding modes within this new cluster structure.

Main Methods:

• Single-crystal X-ray diffraction was employed for structural characterization.
• Synthesis of the [K(2,2,2-crypt)]4{(Ge9)2[η6-Ge(PdPPh3)3]} complex.

Main Results:

• A novel heterometallic sandwich cluster, [K(2,2,2-crypt)]4{(Ge9)2[η6-Ge(PdPPh3)3]}, was successfully synthesized.
• The structure features an unusual heteroatomic metal planar fragment, Ge@Pd3, with a zerovalent germanium core.
• A unique sp2-hybridized germanium bonded to three palladium atoms in a trigonal planar arrangement was observed, capped by nonagermanide ligands.

Conclusions:

• The synthesized cluster represents a rare example of a sandwich compound with a heteroatomic metal planar fragment.
• The study elucidates novel chemical bonding patterns involving palladium-germanium sigma bonds and delocalized sigma bonds.