Palladium(II)/allylpalladium(II) complexes with xanthate ligands: Single-source precursors for the generation of palladium sulfide nanocrystals

In an effort to find simple and common single-source precursors for palladium sulfide nanostructures, palladium(II) complexes, [Pd(S2X)2] (X = COMe (1), COiPr (2)) and η3-allylpalladium complexes with xanthate ligands, [(η3-CH2C(CH3)CR2)Pd(S2X)] (R = H, X = COMe (3); R = H, X = COEt (4); R = H, X = COiPr (5); R = CH3, X = COMe (6)), have been investigated. The crystal structures of [Pd(S2X)2] (X = COMe (1), CoiPr (2)) and [(η3-CH2C(CH3)CH2)Pd(S2COMe)] (3) have been established by single crystal X-ray diffraction analysis. The complexes, 1, 2 and 3 all contain a square planar palladium(II) centre. In the allyl complex 3, this is defined by the two sulfurs of the xanthate and the outer carbons of the 2-methylallyl ligand, while in the complexes, 1 and 2 it is defined by the four sulfur atoms of the xanthate ligand. Thermogravimetric studies have been carried out to evaluate the thermal stability of η3-allylpalladium(II) analogues. The complexes are useful precursors for the growth of nanocrystals of PdS either by furnace decomposition or solvothermolysis in dioctyl ether. The solvothermal decomposition of complexes in dioctyl ether gives a new metastable phase of PdS which can be transformed to the more stable tetragonal phase at 320 °C. The nanocrystals obtained have been characterized by PXRD, SEM, TEM and EDX.

Graphical abstractPalladium(II) complexes, [Pd(S2X)2] (X = COMe or COiPr) and η3-allylpalladium(II) complexes with xanthate ligands, [(η3-CH2C(CH3)CR2)Pd(S2X)] (R = H or Me; X = COMe, COEt, COiPr) have been prepared, structurally characterized and their suitability as single-source precursors for generation of PdS nanostructures has been investigated. The complexes are useful precursors for generation of PdS nanocrystals either by furnace decomposition or solvothermolysis in dioctyl ether.Figure optionsDownload full-size imageDownload as PowerPoint slide