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

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Abstract

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.

Original languageEnglish
Pages (from-to)197-204
Number of pages8
JournalInorganica Chimica Acta
Volume265
Issue number1-2 PART II
Publication statusPublished - 1997 Nov 15
Externally publishedYes

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Methenamine
Acetonitrile
Hydration
acetonitrile
hydration
catalytic activity
acetates
Catalyst activity
Ion exchange
Acetates
Ligands
ligands
synthesis
chelates
X ray analysis
Polyamines
Platinum
platinum
Nuclear magnetic resonance
X-Rays

Keywords

  • Catalytic hydration
  • Cluster complexes
  • Crystal structures
  • Platinum(II) clusters
  • Polyamine complexes

ASJC Scopus subject areas

  • Biochemistry
  • Inorganic Chemistry
  • Physical and Theoretical Chemistry
  • Materials Chemistry

Cite this

@article{05748846bba04307aca2e22c9463c8ba,
title = "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",
abstract = "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) {\AA}, α = 100.23(2), β = 113.9(2), γ = 77.60(2)°, V = 2972(1) {\AA}3, 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.",
keywords = "Catalytic hydration, Cluster complexes, Crystal structures, Platinum(II) clusters, Polyamine complexes",
author = "Akira Shibata and Tadashi Yamaguchi and Tasuku Ito",
year = "1997",
month = "11",
day = "15",
language = "English",
volume = "265",
pages = "197--204",
journal = "Inorganica Chimica Acta",
issn = "0020-1693",
publisher = "Elsevier BV",
number = "1-2 PART II",

}

TY - JOUR

T1 - 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

AU - Shibata, Akira

AU - Yamaguchi, Tadashi

AU - Ito, Tasuku

PY - 1997/11/15

Y1 - 1997/11/15

N2 - 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.

AB - 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.

KW - Catalytic hydration

KW - Cluster complexes

KW - Crystal structures

KW - Platinum(II) clusters

KW - Polyamine complexes

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M3 - Article

AN - SCOPUS:0011594721

VL - 265

SP - 197

EP - 204

JO - Inorganica Chimica Acta

JF - Inorganica Chimica Acta

SN - 0020-1693

IS - 1-2 PART II

ER -