Syntheses of Pd(ii)/Pt(ii) complexes with non-chelating 4-pyridylselenolate ligand ranging from mononuclear to macrocyclic structures and their utility as catalysts in Suzuki C–C coupling reaction

Abstract

Treatment of Na2PdCl4 or [MCl2(PhCN)2] with bis(4-pyridyl)diselenide yielded an insoluble product of composition [MCl2(4,4′-(C5H4N)2Se2)]n (1). The reactions of Na2PdCl4 with one and two eq. of Na(4-SeC5H4N) afforded insoluble products [PdCl(4-SeC5H4N)]n (2) and [Pd(4-SeC5H4N)2]n (3), respectively. On treatment with PPh3, 2 and 3 gave trans-[PdCl(4-SeC5H4N)(PPh3)2] (4a) and trans-[Pd(4-SeC5H4N)2(PPh3)2] (5a), respectively. The oxidative addition of bis(4-pyridyl)diselenide to Pt(PPh3)4 exclusively yielded trans-[Pt(4-SeC5H4N)2(PPh3)2] (5b). The treatment of two eq. of Na(4-SeC5H4N) with cis-[PtX2(PR3)2] afforded 5b (X = Cl) and trans-[Pt(4-SeC5H4N)2(PEt3)2] (5c) (X = Cl or CF3SO3). The reactions of cis-[MCl2(P∩P)] and [M2Cl2(μ-Cl)2(PR3)2] with two eq. of Na(4-SeC5H4N) exclusively yielded cis-[M(4-SeC5H4N)2(P∩P)] (M/P∩P = Pd/dppe (6a), Pt/dppm (6b) and Pt/dppp (6c)) and [MCl(4-SeC5H4N)(PR3)]n (7), respectively. The complex trans-[PtCl(4-SeC5H4N)(PEt3)2] (4b) was isolated from the redistribution reaction between 5c and cis-[PtCl2(PEt3)2]. The complex [PdCl(4-SeC5H4N)(PPh3)]n (7b) exists in bi- and tri-nuclear forms, whereas [MCl(4-SeC5H4N)(PEt3)]n (7a, 7c) and [PtCl(4-SeC5H4N)(PMe2Ph)]n (7d) retain their trinuclear structure in solution. Molecular structures of 4a, 4b, 5a, 5c, 6a, 6c, 7a, 7b and 7c were established by single crystal X-ray diffraction analyses. The complexes trans-[PdCl(4-SeC5H4N)(PPh3)2] and [PdCl(4-SeC5H4N)(PPh3)]n can act as catalysts for Suzuki C–C cross coupling reaction.

Electrochemiluminescence Detection of TNT by Resonance Energy Transfer through the Formation of a TNT–Amine Complex

“…This shift of the CH 2 signal is due to the lower electronegativity of the chalcogen atom than that of Cl. A single signal at δ = 294.7 ppm in the 77 Se{ 1 H} NMR spectrum of diselenide L2 (Figure S13) is within the range reported for organodiselenides 45…”

Supramolecular Pt and Pd Complexes of 4,4′‐Dipyridylditelluride/Diselenide Ligands through Self‐Assembly

“…The stronger affinity of the tellurolate ligand towards the soft Pd II center has been recently demonstrated by us in cis ‐/ trans ‐[PdCl(TeC 5 H 4 N‐4)(PPh 3 )] 2 , in which the ligand bridges two palladium centers through the tellurolate group . Whereas the analogous complex [PdCl(SeC 5 H 4 N‐4)(PPh 3 )] n exists as macrocyclic dimers and trimers, formed by the Se and N atoms of the 4‐pyridylselenolate ligand . The same and similar ionic clusters of the types [M 3 E 2 (dppe) 3 ] 2+ (M = Ni, Pd, Pt; E = S, Se, Te) have been isolated from the reaction of [M II (dppe)(solvent)] 2+ with NaEH .…”

“…We have recently developed the coordination chemistry of Pd II , Pt II , and Ag I with the nonchelating ligands 4‐pyridylselenolate and 4‐pyridyltellurolate, which are the reduced forms of 4,4′‐py 2 E 2 . The bi‐ and tri‐trinuclear macrocyclic structures [MCl(4‐Sepy)(PR 3 )] n (M = Pd, Pt; R = Et, Ph) have been established by the N,Se‐bridging mode of the 4‐pyridylselenolate ligand . Next, we have sought to construct the macrocycles, placing the 4,4′‐py 2 E 2 ligand on the edge and the metal centers at the corners.…”

Synthesis and structure of [(Ph3P)2Cu(μ-SeCH2Ph)2In(SeCH2Ph)2] as a single-source precursor for the preparation of CuInSe2 nano-materials

“…We have recently synthesized the complexes of Cu(I) and In(III) metals, 16 using the hybrid ligands aminoalkylselenolates 17,18 and 4-pyridylselenolates 19,20 and prepared the binary copper and indium selenides. The hard donor N atom present in the above ligands, inhibited to form the SSPs containing Cu, In and Se element, either by chelating or bridging with metal centers thus forming co-ordination polymers.…”