Collection of Czechoslovak Chemical Communications - digital archive 

Abstract

3-Hydrazonocamphor, 3-(RR¹NN)C₁₀H₁₄O (R = Me, R¹ = H), undergoes intramolecular hydrogen bridging by coordination to platinum or palladium. This effect is evidenced by considerable decrease in the ν(C=O) frequency (compared to the free ligand) in the IR spectra of the complexes [MCl₂L₂] (M = Pd, Pt; L = 3-(RR¹NN)C₁₀H₁₄O) as well as by the magnetic non- equivalence of the two ligands, as revealed by ¹³C NMR. DFT calculations indicate that coordination of 3-(Me(H)NN)C₁₀H₁₄O promotes E/Z isomerization of the hydrazono group of the ligand, inducing formation of intramolecular hydrogen bonding and corresponding stabilization of the complex. Characterization of the complexes [MCl₂L₂] (M = Pt; L: R, R¹ = Me (1), R = Me, R¹ = H (2) and M = Pd; L: R = Me, R¹ = H (3)) was performed by analytical and spectroscopic techniques. Redox properties of the 3-hydazonocamphors and their complexes were studied by cyclic voltammetry. The structure of trans-[PtCl₂{3-(Me₂NN)C₁₀H₁₄O}₂] was determined by single-crystal X-ray diffraction analysis. The complex has square-planar geometry and crystallizes in the tetragonal P4₃ space group.

Keywords: Platinum complexes; Palladium; Camphorimine; Hydrazones; Hydrogen bonding; DFT calculations; Cyclic voltammetry; IR spectroscopy.

References: 42 live references.