New dinuclear palladium complex with a Chinese-lantern structure

Formation of polynuclear palladium complexes with the benzimidazole-2-thiolate anion

“…The ligands L and L F exist in the thione tautomeric form. In this case, both nitrogen atoms are protonated, resulting in the formation of C=S double bonds (C=S, 1.721 (8) The situation is different with the reaction of HL with K 2 PdCl 4 in the ethanol-water system (5 : 1) with the use of the reagent ratio of 2 : 1 in the absence of HCl. This reaction afforded the poorly soluble tetranuclear complex Pd 4 (L) 2 (µ 3 S,N (L)) 2 (µ S,N (L)) 4 (3) (see Scheme 1) as the major product in 62.5% yield.…”

“…Since no deprotonation was observed in the case of platinum, this problem can be solved with the use of palladium(II) salts taking into account that palladium is a somewhat harder element that forms stable complexes with both S and N donor ligands. 7 Earlier, 8 we have reported the synthesis of the lantern type dinuclear com plex Pd 2 (µ S,N L) 4 , in which the benzimidazolethiolate ligands serve as S,N bridges. In the present study, we describe the results of detailed investigation into the reac tion of HL and its 6,7 difluorinated analog HL F , which is more readily soluble in organic solvents, with Pd II deriva tives, as well as the structures of the newly synthesized polynuclear complexes.…”

Electrochemical chiral recognition by microparticle coatings of Pd complexes with bridging cyclometalated phosphines

“…Since the electrocatlytic process may involve coordination of glutamic acid (strictly, glutamate ion) with the Pd 2 L 2 complex coupled with oxidation/reduction cycles, the electrochemical response of Pd 2 L 2 in CH 2 Cl 2 solution and in solid state in the presence of chloride and acetate ions has also been studied. These preliminary studies are motivated by the recognized dependence of the catalytic ability of dinuclear palladium complexes on the extent of the possible synergic interaction between metal atoms [16][17][18][19][20][21][22][23][24][25], and the ability of exogen ligands such as chloride or carboxylate for modulating such interaction [18,20,25]. Interestingly, oxidation potentials and electrochemical reversibility are significantly influenced by the ligand nature, as can be seen on comparing reported electrochemical data for palladium dinuclear complexes with pyridines [20,25] and those with carboxylates [28].…”

“…This is the case of some dinuclear palladium(II) complexes containing two bridging ligands and two cyclometalated units with the ligand having a chelating coordination mode [15]. The availability of high oxidation states of palladium and the possibility of modulating the reactivity of the complexes via synergic interaction between the metal centres can be considered as relevant factors with regard to the use of such compounds in catalysis [16], so that different dinuclear palladium compounds with bridging ligands have been synthesized [17][18][19][20][21][22][23][24][25].…”

Syntheses and crystal structures of mononuclear and dinuclear (pentamethylcyclopentadienyl)iridium(III) complexes containing 2-mercaptobenzimidazole

“…When H 2 bimt is deprotonated to form a monoanionic Hbimt À or a dianionic bimt 2À , the imidazolate nitrogen can also be bound to a metal ion. Therefore, a variety of coordination and bridging modes become possible for H n bimt (2Àn)À (n = 0, 1, or 2) [6][7][8][9][10][11]. Furthermore, because the coordinated H n bimt (2Àn)À can be incorporated into hydrogen-bonding network as a donor (via imidazole N-H) or an acceptor (via imidazolate N or thiolate S), and because the planar benzimidazole ring is possible to form a p-p stacking interaction in the crystal, H 2 bimt and the deprotonated ions are versatile ligands in construction of coordination polymers or metal-organic frameworks (MOFs).…”