[Bis-(diphenyl-phosphino)methane-κP,P']dichloridopalladium(II)

Area of Science:

• Inorganic Chemistry
• Crystallography
• Materials Science

Background:

• The palladium dichloride bis-(diphenyl-phosphino)methane complex, [PdCl2(dppm)], is known, with a previously described crystal structure.
• Polymorphism in coordination complexes can significantly alter material properties.

Purpose of the Study:

• To characterize a distinct polymorph of [PdCl2(dppm)] and elucidate its unique molecular arrangement.
• To compare the observed structure with previously reported polymorphs and related platinum analogues.

Main Methods:

• Single-crystal X-ray diffraction analysis was employed to determine the crystal structure.
• Analysis of molecular arrangement, symmetry, and disorder within the crystal lattice.

Main Results:

• A new polymorph crystallizing in space group C2/c was identified, distinct from the previously reported P2(1)/n structure.
• The structure features chains of C2-symmetric molecules with disorder in the bis-(diphenyl-phosphino)methane ligand and palladium atom positions.
• Disorder results in a reversal of chain direction along the b-axis, with phenyl rings and chloride atoms not participating in the disorder.

Conclusions:

• The identified polymorph exhibits a unique chain-like arrangement with significant orientational disorder.
• The observed disorder suggests a potential for an incommensurate superstructure, not fully resolved by Bragg diffraction.
• This finding contributes to the understanding of structural diversity and polymorphism in palladium coordination complexes.