Pyrazole‐Stabilized Dinuclear Palladium(II) Chalcogenolates Formed by Oxidative Addition of Bis[2‐(4‐bromopyrazol‐1‐yl)ethyl] Dichalcogenides to Palladium(II) – Tailoring of Pd–S/Se Nanoparticles. Issue 29 (9th September 2015)

• Record Type: Journal Article
• Authors: Nayan Sharma, Kamal; Joshi, Hemant; Prakash, Om; Sharma, Alpesh K.; Bhaskar, Renu; Singh, Ajai K.
• Is Part Of: European journal of inorganic chemistry. Issue 29(2015)
• Page Start: 4829
• Page End: 4838
• Publication Date: 2015-09-09
• Subjects: Nanoparticles -- Palladium -- ­Ligand design -- Chalcogenolates -- ­Oxidative addition -- Dichalcogenides; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.201500529
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract: Bis[2‐(4‐bromopyrazol‐1‐yl)ethyl] disulfide and diselenideL1 andL2 were synthesized by the reactions of 4‐bromo‐1‐(2‐chloroethyl)‐1 H ‐pyrazole with the in situ generated Na2 S2 and Na2 Se2 . The reactions ofL1 andL2 with 2 equiv. of [PdCl2 (CH3 CN)2 ] in CH3 CN at 70 °C proceed through an oxidative addition/reductive elimination sequence to the Pd II center to form the chalcogenolato‐bridged dinuclear palladium(II) complexes [Pd2 Cl2 (μ‐EN)2 ] [1 (E = S) and2 (E = Se); EN = 2‐(4‐bromopyrazol‐1‐yl)ethanechalcogenolate]. The reactions of1 and2 with CH3 CN and AgBF4 resulted in the formation of [Pd2 (CH3 CN)2 (μ‐EN)2 ]· 2BF4 (3 and4 ). CompoundsL1, L2, and their complexes1 –4 have been characterized through 1 H, 13 C{ 1 H}, and 77 Se{ 1 H} nuclear magnetic resonance (NMR) spectroscopy; infrared (IR) spectroscopy; and high‐resolution mass spectrometry (HRMS). The single‐crystal X‐ray structures of2 –4 have revealed distorted square‐planar geometries around the Pd center in each case. The Pd–S and Pd–Se bond lengths are in the ranges 2.277(2)–2.296(2) and 2.372(9)–2.3971(17) Å, respectively. Single‐source precursor routes for the synthesis of palladium chalcogenide nanoparticles (NPs) have been developed by the thermolyses of1 –4 in 1:1 mixtures of oleic acid (OA) and 1‐octadecene (ODE). Pd17 Se15 NPs were formed from both Pd II selenolates2 and4, whereas Pd4 S NPs and a mixture of Pd16 S7 (ca. 68 %) and PdS (ca. 32 %) NPs were obtained from Pd II thiolates1 and3, respectively. Transmission electron microscopy (TEM), scanning electron microscopy with energy‐dispersive X‐ray spectroscopy (SEM‐EDX), and powder X‐ray diffraction (PXRD) have been used to authenticate the NPs. X‐ray photoelectron spectroscopy (XPS) studies on the NPs have revealed that there is a charge transfer from Pd to S/Se. The compositions of the NPs determined from XPS are consistent with the PXRD results. Abstract : The thermolyses of chalcogenolato‐bridged dinuclear Pd II complexes of pyrazole‐based thiolates and selenolates in 1:1 mixtures of oleic acid (OA) and 1‐octadecene (ODE) afford Pd17 Se15, Pd4 S, and Pd16 S7 + PdS nanoparticles (NPs).