Synthesis and charactrization palladium polysulfide complexes of N-heterocyclic carbenes

Palladium(II) polysulfide complexes [(PdL)(4)(mu(4)-S-2)(2)](PF6)(4), [PdL(mu 2-S-4)], [(PdL)(2)(mu(4)-S-5)](PF6)(2), and [(PdL)(3)(mu(3)-S)(2)](PF6)(2) have been synthesized through the reactions of [PdL(NH3)(2)](PF6)(2) and [PdL(CH3CN)(2)](PF6)(2) (L = 1,1'-di(R)-3,3'-methylenediimidazolin-2,2'-diylidene, R = methyl, ethyl, isopropyl, and mesityl) with element sulfur, thiourea or (Bu4N)(2)S-6, respectively. [(PdL)(4)(mu(4)-S-2)(2)](PF6)(4) features four [PdL](2+) units joined by two S-2(2-) ligands in which each sulfur bonds to two palladium ions. The neutral complexes [PdL(mu(2)-S-4)] consist of a S-4(2-) chain anion chelated to the palladium ion with two terminal sulfur atoms. In [(PdL)(2)(mu(4)-S-5)](PF6)(2) two [Pd](2+) units are held together by a S-5(2-) ligand forming two six-membered [PdS5] rings with chair and boat conformation. Trinuclear complex [(PdL2)(3)(mu(3)-S)(2)](PF6)(2) contains three [PdL](2+) units held by two tridenate S2- ions forming a trigonal bipyramidal Pd3S2 structure. (C) 2013 Elsevier B.V. All rights reserved.