Synthesis and property of pentakis(μ-acetato-O,O′) (linear-hexamine)tetraplatinum(II), [Pt4(μ-acetato-O,O′)5(L)]3+; correlation between rate of in-plane acetate ligand exchange and catalytic activity for hydration of acetonitrile

Akira Shibata, Tadashi Yamaguchi, Tasuku Ito*

*この研究の対応する著者

研究成果査読

13 被引用数 (Scopus)

抄録

Three new hexadentate polyamine ligands (L), their acetate bridged tetranuclear platinum complexes, [Pt4(μ-CH3COO)5(L)]3+ (L3 = 1,5,8,11,14,18-hexaazaoctadecane (3), L5 = 1,11-bis(2-pyridylmethyl)-1,4,8,11-tetraazaundecane (5), L6 = N,N′-bis(((2-pyridylmethyl)amino)ethyl)piperazine (6), and the same type of Pt4 complex with L4 = 1,10-bis(2-pyridylmethyl)-1,4,7,10-tetraazadecane) (4) were prepared. Single crystal X-ray analysis of 6(ClO4)3·2C4H6O 3-CHCl3 shows that the hexamine ligand with the sequence of the bridge-chelate-bridge-chelate-bridge mode and one acetate occupy coordination sites in the plane of the cluster. Crystal data: triclinic space group P 1̄, a = 14.001(4), b = 19.029(3), c = 12.562(3) Å, α = 100.23(2), β = 113.9(2), γ = 77.60(2)°, V = 2972(1) Å3, Z = 2. Ligand exchange rates of the in-plane acetate ligand in these complexes were determined by means of 1H NMR in CD3CN at 25°C: k = 1.2 × 10-2 for 3, 1.4 × 10-4 for 4, 8.7 × 10-6 for 5, 1.2 × 10-6 mol-1 kg s-1 for 6. All the Pt4 complexes show, to some extent, catalytic activity for hydration of acetonitrile to give acetamide: turnover number per hour under experimental conditions was 0.51 for 3, 0.46 for 4, 0.09 for 5, and 0.09 for 6, respectively. It was found, for the series of compounds including [Pt4(μ-CH3COO)8] and [Pt4(μ-CH3COO)6(3,2,3-tet)], that a qualitatively positive correlation holds between the ligand exchange rate and the catalytic activity, that is, the faster the ligand exchange, the higher the catalytic activity in general. This fact indicates that the catalytic activity is associated with the lability of coordination sites trans to the Pt-Pt bond.

本文言語English
ページ(範囲)197-204
ページ数8
ジャーナルInorganica Chimica Acta
265
1-2 PART II
DOI
出版ステータスPublished - 1997 11 15
外部発表はい

ASJC Scopus subject areas

  • 物理化学および理論化学
  • 無機化学
  • 材料化学

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「Synthesis and property of pentakis(μ-acetato-O,O′) (linear-hexamine)tetraplatinum(II), [Pt<sub>4</sub>(μ-acetato-O,O′)<sub>5</sub>(L)]<sup>3+</sup>; correlation between rate of in-plane acetate ligand exchange and catalytic activity for hydration of acetonitrile」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

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