Synthesis, characteristics and catalytic activity of water-soluble [Pd(lysine·HCl)(Cl)2] complex as hydrogenation catalyst

(S)-α-Benzyl-prolinium cis-[(S)-α-benzyl-prolinato]dichloridopalladium(II)

The title complex salt, (C₁₂H₁₆NO₂)[PdCl₂(C₁₂H₁₄NO₂)], is of inter­est with respect to organic and organometallic catalysis. The compound crystallizes as very small orange–red irregular prisms and the asymmetric unit contains three crystallographically distinct cation–anion pairs. The coordination geometry about the palladium atoms is square-planar with the chloride ligands cis to one another. The structure displays N—H⋯Cl and O—H⋯O hydrogen bonding such that the N—H⋯Cl hydrogen bonds align the cation–anion pairs in a linear fashion along [001], with the O—H⋯O hydrogen bonds connecting these linear strands along [100] and [010].

Bis(hydrogen l-glutamato)palladium(II)

In the title compound, [Pd(C₅H₈NO₄)₂], the Pd(II) atom is coordinated by two O atoms and two N atoms of two N,O-chelating hydrogen l-glutatmate ligands in a square–planar geometry with the N and O atoms in a mutually trans arrangement. The complex units are embedded in a network of N—H⋯O and O—H⋯O hydrogen-bonding inter­actions that stabilize the three-dimensional crystal structure. The strongest hydrogen bonds are formed between the γ-COOH untis of adjacent glutamate ligands, leading to dimers of the type R₂²(8) with O⋯O separations of 2.640 (6) Å.