Rhodium Nanoparticles from Dirhodium(II) Ethylene Glycol Tetracarboxylates

Abstract

A straightforward synthesis methodology for the preparation of rhodium(II) carboxylates [Rh 2 {O 2 CCH 2 (OCH 2 CH 2 ) 2 -OCH 3 } 4 ] n (1) and [Rh{μ-O 2 CCH 2 (OCH 2 CH 2 ) 2 OCH 3 } 2 -(PPh 3 )] 2 (2) is reported. The ethanol-mediated reduction of RhCl 3 ·3H 2 O with [K{O 2 CCH 2 (OCH 2 CH 2 ) 2 OCH 3 }] produced 1, which on further addition of PPh 3 afforded 2. Single-crystal X-ray diffraction studies of 2 were carried out showing a paddlewheel arrangement of the dirhodium(II) tetracarboxylate unit with a Rh-Rh distance of 2.4599(5) Å. Compounds 1 and 2 were applied in the formation of rhodium nanoparticles (NPs) using 1,2-ethanediol as reducing reagent and poly-(vinylpyrrolidone) (PVP) as capping component. Rhodium NPs with a narrow size distribution (Ͻ4 nm) were obtained [a]

Dirhodium(II,II) Paddlewheel Complexes

“… Dirhodium(II,II) complexes containing O , O' ‐bridging ligands with structural motive OOCCH 2 Het; Het=heteroatom: M1 , [111] M2 , [184] M3 , [182] M4 [182] …”

Catalysts Originating from Tailor‐made Metal Ethylene Glycol Carboxylates

“…Heterogeneous Catalysis [56,85] To elucidate the decomposition mechanism of the metal carboxylates, thermogravimetry (= TG) and mass spectrometry-coupled TG (= TG-MS) studies were carried out. [56][57][58][59][60][61][62][63][64][65][66][67][68][69] [60][61][62]64] Afterwards, the Lewis base ligands L are eliminated producing [M(CH 2 (OCH 2 CH 2 ) n OMe) m ]. Homolytic cleavage of the MÀ C alkyl bond gave M(0) and organic ethylene glycol-based species.…”

“…[54,55] Contrary to these classical methodologies, a single source process was recently introduced by our group using ethylene glycol metal carboxylates of type [L x M(O 2 CCH 2 (OCH 2 CH 2 ) n OMe) m ] y (L x M = (PR 3 ) 2 Cu, (PR 3 )Ag, (PPh 3 )Au, (PR 3 ) 2 Pd, (PR 3 ) 2 Pt, (PR 3 ) 2 (CO) 2 Ru, (PR 3 )Rh; n = 0, 1, 2, 3, 4, 5, 7.33; m = 1, 2; y = 1, 2) and [M(O 2 CCH 2 (OCH 2 CH 2 ) n OMe) m ] (M = Ag, Co, Cu; m, n = 1, 2) (Scheme 1). [56][57][58][59][60][61][62][63][64][65][66][67][68][69] The advantage of this approach is an easy reaction control over the straightforward formation of unique and tailored NPs with no need for both, the addition of reducing agents and stabilizing additives. [60,70] Thereby, the respective metal carboxylates follow a first order low-temperature decomposition mechanism with high reproducibility.…”

Size and shape controlled synthesis of rhodium nanoparticles

“…In recent years, a lot of research has been done on the formation of NMNPs using the polyol process, which is one of the most commonly used solution-based approaches to colloidal NMNPs for plasmonic and catalytic applications [50, 51, 52, 53, 54, 55, 56]. To produce a metal colloid, an organic metal compound or salt precursor is heated, usually in the presence of stabilizers, in high boiling polyols as solvents as well as reducing agents.…”