Novel chiral-at-metal pseudotetrahedral Ru(II) complex
of a chiral selenated Schiff base: synthesis, characterization,
absolute crystal structure and Hirshfeld surface analysis

A novel ruthenium(II) complex, [Ru(p-cymene)((R)-L)](PF₆) ((R)-1) of a chiral selenated Schiff base ligand, (2R)-BnSeCH₂CH(CH₃)N=CH-C₁₀H₈-2-OH ((R)-LH) is synthesized and characterized by elemental analysis, ¹H/¹³C{¹H} NMR and FTIR spectroscopy. The characterisation data of the complex, (R)-1 reveal that, the conjugate base ((R)-L) of the chiral ligand is found to be coordinated in a tridentate (Se, N, O^–) mode to the central Ru(II) ion. The resulting product contains a mixture of the two diastereomers of the complex containing two chiral centers, one at carbon and another chiral-at-metal. One of the diastereomers of the complex is obtained on recrystallization of the product into an orange-red crystalline compound. The absolute molecular crystal structure of this diastereomer is determined by single crystal X-ray diffraction. The crystal data reveal that the complex crystallizes in the orthorhombic crystal system in the space group P2₁2₁2₁. The bond parameters demonstrate that the complex has half-sandwich pseudotetrahedral geometry around the Ru(II) ion. The flack parameter (x = 0.06(3)) further confirms the presence of a single diastereomer in the crystalline sample of the complex, (R)-1. In the molecular crystals of the complex, there exists Se⋯F (3.206 Å), CH⋯O (2.00 Å) and CH⋯F (2.46 to 2.62 Å) type of intermolecular secondary bonding interactions resulting in supramolecular structure. The intermolecular interactions exhibited by the crystalline environment of the complex are evaluated by the Hirshfeld surface (HS) analysis.

This is an excerpt of the article

Novel Chiral-at-metal pseudotetrahedral Ru(II) complex
of a chiral selenated Schiff base: Synthesis, Characterization,
Absolute Crystal Structure and Hirshfeld Surface Analysis.

Full text of the paper is published in Journal of Structural Chemistry.
DOI: 10.1134/S0022476626050161