Synthesis, crystal structure and Hirshfeld analysis of trans-bis(2-{1-[(6R,S)-3,5,5,6,8,8-hexamethyl-5,6,7,8-tetrahydronaphthalen-2-yl]ethylidene}-N-methylhydrazinecarbothioamidato-κ2 N 2,S)palladium(II) ethanol monosolvate

Abstract

The reaction between the (R,S)-fixolide 4-methylthiosemicarbazone and PdII chloride yielded the title compound, [Pd(C20H30N3S)2]·C2H6O {common name: trans-bis[(R,S)-fixolide 4-methylthiosemicarbazonato-κ2 N 2 S]palladium(II) ethanol monosolvate}. The asymmetric unit of the title compound consists of one bis-thiosemicarbazonato PdII complex and one ethanol solvent molecule. The thiosemicarbazononato ligands act as metal chelators with a trans configuration in a distorted square-planar geometry. A C—H...S intramolecular interaction, with graph-set motif S(6), is observed and the coordination sphere resembles a hydrogen-bonded macrocyclic environment. Additionally, one C—H...Pd anagostic interaction can be suggested. Each ligand is disordered over the aliphatic ring, which adopts a half-chair conformation, and two methyl groups [s.o.f. = 0.624 (2):0.376 (2)]. The disorder includes the chiral carbon atoms and, remarkably, one ligand has the (R)-isomer with the highest s.o.f. value atoms, while the other one shows the opposite, the atoms with the highest s.o.f. value are associated with the (S)-isomer. The N—N—C(=S)—N fragments of the ligands are approximately planar, with the maximum deviations from the mean plane through the selected atoms being 0.0567 (1) and −0.0307 (8) Å (r.m.s.d. = 0.0403 and 0.0269 Å) and the dihedral angle with the respective aromatic rings amount to 46.68 (5) and 50.66 (4)°. In the crystal, the complexes are linked via pairs of N—H...S interactions, with graph-set motif R 2 2(8), into centrosymmetric dimers. The dimers are further connected by centrosymmetric pairs of ethanol molecules, building mono-periodic hydrogen-bonded ribbons along [011]. The Hirshfeld surface analysis indicates that the major contributions for the crystal cohesion are [atoms with highest/lowest s.o.f.s considered separately]: H...H (81.6/82.0%), H...C/C...H (6.5/6.4%), H...N/N...H (5.2/5.0%) and H...S/S...H (5.0/4.9%).