om000223y_si_001.cif (32.36 kB)

Reactivity of [M(C∧P)(acac-O,O‘)] [M = Pt, Pd; C∧P = CH2-C6H4-P(o-tolyl)2-κC,P; acac = 2,4-pentanedionato] toward HgX2 (X = Br, I, CH3COO, CF3COO). New Polynuclear Complexes Containing Pt−Hg Bonds. Molecular Structures of [{Pt(C∧P)(acac-O,O‘)- HgBr(μ-Br)}2(μ-HgBr2)], an Unprecedented Square-Planar Bromomercurate Complex, and [{Pt(C∧P)(μ-O2CCH3)2Hg(μ3-acac2--κC3,O)Hg(O2CCH3-κO)}· CHCl3]2, the First Complex Containing Asymmetric Dimercurated Acetylacetone

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posted on 11.07.2000, 00:00 by Irene Ara, Larry R. Falvello, Juan Forniés, Violeta Sicilia, Pablo Villarroya
The complexes [M(C∧P)(acac-O,O‘)] [M = Pt (1) Pd (1‘); C∧P = CH2-C6H4-P(o-tolyl)2-κC,P; acac = 2,4-pentanedionato] were prepared by the reaction of [M(C∧P)(μ-Cl)]2 [M = Pt, Pd] with Tl(acac) and fully characterized. The reactions of [Pt(C∧P)(acac-O,O‘)] (1) with equimolar amounts of HgX2 (X = I, Br) give the polynuclear complexes [Pt(C∧P)(acac-O,O‘)HgI(μ-I)]2 (2) and [{Pt(C∧P)(acac-O,O‘)HgBr(μ-Br)}2(μ-HgBr2)] (3) containing unsupported Pt-to-Hg donor bonds. In the pentanuclear complex 3, the central mercury atom shows an unexpected square-planar environment, unprecedented for halomercurates(II). The complex [Pt(C∧P)(acac-O,O‘)] (1) also reacts with Hg(O2CR)2 (R = CH3, CF3), but in 1:2 molar ratio, to afford the neutral hexanuclear complexes [Pt(C∧P)(μ-O2CR)2Hg(μ3-acac2--κC3,O)Hg(O2CR-κO)]2 [R = CH3 (4), CF3 (5)]. An X-ray study of 4 revealed that these compounds contain very short platinum-to-mercury donor bonds supported by two carboxylate groups, along with an unusual dimercurated acetylacetone moiety. The reactions of [Pd(C∧P)(acac-O,O‘)] (1‘) with HgX2 (X = Br, I, CH3COO, CF3COO) proceed mainly (X = Br, CH3COO, CF3COO) with substitution of the acac-O,O‘ ligand by X from the coordination environment of the palladium center to give the binuclear derivatives [Pd(C∧P)(μ-X)]2 (X = Br, CH3COO, CF3COO), hindering the obtention of palladium−mercury compounds by this route.