Synthesis by ligand exchange and electrochemistry of ruthenocenyl-containing β-diketonato complexes of titanocene. Structure of [TiCp2(RcCOCHCOCH3)][ClO4]

Elizabeth Erasmus; Alfred J. Muller; Uwe Siegert; Jannie C. Swarts

doi:10.1016/j.jorganchem.2016.05.011

Synthesis by ligand exchange and electrochemistry of ruthenocenyl-containing β-diketonato complexes of titanocene. Structure of [TiCp₂(RcCOCHCOCH₃)][ClO₄]

Elizabeth Erasmus, Alfred J. Muller, Uwe Siegert, Jannie C. Swarts

Chemical Sciences

University of The Free State

Research output: Contribution to journal › Article › peer-review

7 Citations (Scopus)

Abstract

A new synthetic route involving ligand exchange towards a series of ruthenocenyl-containing β-diketonato titanocene complexes of the type [Ti^IV(C₅H₅)₂(RcCOCHCOR)][ClO₄] with Rc = Ru^II(C₅H₅)(C₅H₄) and R = C₁₀F₂₁(1), CF₃(2), C₆F₅(3), C₁₀H₂₁(4), CH₃(5), Rc (6) and Fc = Fe^II(C₅H₅)(C₅H₄) (7) are described. The complex [Ti^IV(C₅H₅)₂(RcCOCHCOCH₃)][ClO₄], 5, (Z = 4) crystallised in the monoclinic space group P2₁/n. A cyclic voltammetric electrochemical study in CH₂Cl₂/0.1 M [NBu₄][B(C₆F₅)₄] showed the one-electron transfer redox processes of the Ti^III/Ti^IVand Rc/Rc⁺couples exhibited irreversible electrochemical behaviour. In CH₃CN/0.1 M [N(ⁿBu)₄][PF₆], the ruthenocenyl couple switched to an electrochemically and chemically irreversible two-electron transfer redox couple, Rc/Rc²⁺, involving the Ru^IVredox centre. The redox potentials of the Ti^III/Ti^IV, Rc/Rc⁺and Rc/Rc²⁺couples were in the range −642 < E^o'< −1479 mV (both solvents), 1016 mV < E^o'< 1034 mV (CH₂Cl₂) and 609 mV < E^o'< 832 mV (CH₃CN) vs. the free ferrocene couple, FcH/FcH⁺, respectively. The Fc/Fc⁺redox process associated with 7 was observed at E^o'= 0.259 (CH₃CN) and 0.235 V (CH₂Cl₂). The cytotoxicity of [Ti^IV(C₅H₅)₂(RcCOCHCOCF₃)][ClO₄], 2, against CoLo DM320 and HeLa cells, IC₅₀= 10.2 and 9.7 μmol dm⁻³respectively, was found to be in the same order of magnitude as those of the free ligand, RcCOCH₂COCF₃.

Original language	English
Pages (from-to)	62-70
Number of pages	9
Journal	Journal of Organometallic Chemistry
Volume	821
DOIs	https://doi.org/10.1016/j.jorganchem.2016.05.011
Publication status	Published - 2016

Keywords

Crystal structure
Cyclic voltammetry
Cytotoxicity
Ruthenocene
Titanocene
β-diketonates

ASJC Scopus subject areas

Biochemistry
Physical and Theoretical Chemistry
Organic Chemistry
Inorganic Chemistry
Materials Chemistry

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10.1016/j.jorganchem.2016.05.011

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@article{b0e61f20258646b2b0af31cc5b049312,

title = "Synthesis by ligand exchange and electrochemistry of ruthenocenyl-containing β-diketonato complexes of titanocene. Structure of [TiCp2(RcCOCHCOCH3)][ClO4]",

abstract = "A new synthetic route involving ligand exchange towards a series of ruthenocenyl-containing β-diketonato titanocene complexes of the type [TiIV(C5H5)2(RcCOCHCOR)][ClO4] with Rc = RuII(C5H5)(C5H4) and R = C10F21(1), CF3(2), C6F5(3), C10H21(4), CH3(5), Rc (6) and Fc = FeII(C5H5)(C5H4) (7) are described. The complex [TiIV(C5H5)2(RcCOCHCOCH3)][ClO4], 5, (Z = 4) crystallised in the monoclinic space group P21/n. A cyclic voltammetric electrochemical study in CH2Cl2/0.1 M [NBu4][B(C6F5)4] showed the one-electron transfer redox processes of the TiIII/TiIVand Rc/Rc+couples exhibited irreversible electrochemical behaviour. In CH3CN/0.1 M [N(nBu)4][PF6], the ruthenocenyl couple switched to an electrochemically and chemically irreversible two-electron transfer redox couple, Rc/Rc2+, involving the RuIVredox centre. The redox potentials of the TiIII/TiIV, Rc/Rc+and Rc/Rc2+couples were in the range −642 < Eo'< −1479 mV (both solvents), 1016 mV < Eo'< 1034 mV (CH2Cl2) and 609 mV < Eo'< 832 mV (CH3CN) vs. the free ferrocene couple, FcH/FcH+, respectively. The Fc/Fc+redox process associated with 7 was observed at Eo'= 0.259 (CH3CN) and 0.235 V (CH2Cl2). The cytotoxicity of [TiIV(C5H5)2(RcCOCHCOCF3)][ClO4], 2, against CoLo DM320 and HeLa cells, IC50= 10.2 and 9.7 μmol dm−3respectively, was found to be in the same order of magnitude as those of the free ligand, RcCOCH2COCF3.",

keywords = "Crystal structure, Cyclic voltammetry, Cytotoxicity, Ruthenocene, Titanocene, β-diketonates",

author = "Elizabeth Erasmus and Muller, {Alfred J.} and Uwe Siegert and Swarts, {Jannie C.}",

note = "Publisher Copyright: {\textcopyright} 2016 Elsevier B.V.",

year = "2016",

doi = "10.1016/j.jorganchem.2016.05.011",

language = "English",

volume = "821",

pages = "62--70",

journal = "Journal of Organometallic Chemistry",

issn = "0022-328X",

publisher = "Elsevier",

}

TY - JOUR

T1 - Synthesis by ligand exchange and electrochemistry of ruthenocenyl-containing β-diketonato complexes of titanocene. Structure of [TiCp2(RcCOCHCOCH3)][ClO4]

AU - Erasmus, Elizabeth

AU - Muller, Alfred J.

AU - Siegert, Uwe

AU - Swarts, Jannie C.

PY - 2016

Y1 - 2016

N2 - A new synthetic route involving ligand exchange towards a series of ruthenocenyl-containing β-diketonato titanocene complexes of the type [TiIV(C5H5)2(RcCOCHCOR)][ClO4] with Rc = RuII(C5H5)(C5H4) and R = C10F21(1), CF3(2), C6F5(3), C10H21(4), CH3(5), Rc (6) and Fc = FeII(C5H5)(C5H4) (7) are described. The complex [TiIV(C5H5)2(RcCOCHCOCH3)][ClO4], 5, (Z = 4) crystallised in the monoclinic space group P21/n. A cyclic voltammetric electrochemical study in CH2Cl2/0.1 M [NBu4][B(C6F5)4] showed the one-electron transfer redox processes of the TiIII/TiIVand Rc/Rc+couples exhibited irreversible electrochemical behaviour. In CH3CN/0.1 M [N(nBu)4][PF6], the ruthenocenyl couple switched to an electrochemically and chemically irreversible two-electron transfer redox couple, Rc/Rc2+, involving the RuIVredox centre. The redox potentials of the TiIII/TiIV, Rc/Rc+and Rc/Rc2+couples were in the range −642 < Eo'< −1479 mV (both solvents), 1016 mV < Eo'< 1034 mV (CH2Cl2) and 609 mV < Eo'< 832 mV (CH3CN) vs. the free ferrocene couple, FcH/FcH+, respectively. The Fc/Fc+redox process associated with 7 was observed at Eo'= 0.259 (CH3CN) and 0.235 V (CH2Cl2). The cytotoxicity of [TiIV(C5H5)2(RcCOCHCOCF3)][ClO4], 2, against CoLo DM320 and HeLa cells, IC50= 10.2 and 9.7 μmol dm−3respectively, was found to be in the same order of magnitude as those of the free ligand, RcCOCH2COCF3.

AB - A new synthetic route involving ligand exchange towards a series of ruthenocenyl-containing β-diketonato titanocene complexes of the type [TiIV(C5H5)2(RcCOCHCOR)][ClO4] with Rc = RuII(C5H5)(C5H4) and R = C10F21(1), CF3(2), C6F5(3), C10H21(4), CH3(5), Rc (6) and Fc = FeII(C5H5)(C5H4) (7) are described. The complex [TiIV(C5H5)2(RcCOCHCOCH3)][ClO4], 5, (Z = 4) crystallised in the monoclinic space group P21/n. A cyclic voltammetric electrochemical study in CH2Cl2/0.1 M [NBu4][B(C6F5)4] showed the one-electron transfer redox processes of the TiIII/TiIVand Rc/Rc+couples exhibited irreversible electrochemical behaviour. In CH3CN/0.1 M [N(nBu)4][PF6], the ruthenocenyl couple switched to an electrochemically and chemically irreversible two-electron transfer redox couple, Rc/Rc2+, involving the RuIVredox centre. The redox potentials of the TiIII/TiIV, Rc/Rc+and Rc/Rc2+couples were in the range −642 < Eo'< −1479 mV (both solvents), 1016 mV < Eo'< 1034 mV (CH2Cl2) and 609 mV < Eo'< 832 mV (CH3CN) vs. the free ferrocene couple, FcH/FcH+, respectively. The Fc/Fc+redox process associated with 7 was observed at Eo'= 0.259 (CH3CN) and 0.235 V (CH2Cl2). The cytotoxicity of [TiIV(C5H5)2(RcCOCHCOCF3)][ClO4], 2, against CoLo DM320 and HeLa cells, IC50= 10.2 and 9.7 μmol dm−3respectively, was found to be in the same order of magnitude as those of the free ligand, RcCOCH2COCF3.

KW - Crystal structure

KW - Cyclic voltammetry

KW - Cytotoxicity

KW - Ruthenocene

KW - Titanocene

KW - β-diketonates

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U2 - 10.1016/j.jorganchem.2016.05.011

DO - 10.1016/j.jorganchem.2016.05.011

M3 - Article

AN - SCOPUS:84975142414

SN - 0022-328X

VL - 821

SP - 62

EP - 70

JO - Journal of Organometallic Chemistry

JF - Journal of Organometallic Chemistry

ER -