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Christopher R. Clough coauthored research on triphenylphosphine.^[ref]

Triphenylphosphine is $\mathrm{PP}{\mathrm{h}}_3$, a neutral phosphine ligand whose phenyl substituents affect both steric demand and electronic donation.

Jared S. Silvia coauthored synthesis and structural characterization of a molybdenum tricarbonyl coordination complex with a cyclic trimetaphosphate ligand. The isolated material contains an organic counterion.

Crystallographic determination of ligand geometry establishes molecular connectivity, while isolation with a specified counterion establishes which salt was actually obtained. These are complementary experimental claims.^[ref]

A reasonable product is sodium facial trimetaphosphate–molybdenum tricarbonyl, with the anionOne terminal O from each phosphorus binds Mo; the three O donors occupy one octahedral face, while the three carbonyls occupy the opposite face. The ring bridges remain P–O–P bridges and are not replaced by Mo–P bonds. Mo remains Mo(0), $d^6$, and $6+3(2)+3(2)=18$ electrons. Overall,acetonitrile can transiently replace CO during heating, but it is not required in the final six-coordinate proposal. The same anion has been structurally characterized with a different counterion: that primary study independently supports the facial O${}_3$/CO${}_3$ connectivity, without establishing identical solubility or yield for the sodium salt.^[ref]

Peter Müller coauthored crystallographic characterization of a trimetaphosphate-bound molybdenum tricarbonyl anion. The structure establishes facial oxygen coordination of the phosphate ligand.

The result shows how a cyclic oxyanion can act as a multidentate ligand. Counterion identity and coordination geometry remain distinct parts of the characterization.^[ref]