Displacement of aqua ligands from the hydroxopentaaquarhodium(III) ion by pyridine-2-aldoxime: A kinetic and mechanistic approach

Ghosh, Aditi; Ghosh, Shyamal; De, G S

doi:10.1007/bf00139034

Cited by 7 publications

(3 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus, there is no problem in calculating both the rate constants. The 2 and are calculated in a manner similar to (11), and data are collected in Table 3.…”

Section: Ligandmentioning

confidence: 99%

“…Thus, it is expected that aqua complexes if used directly will be less toxic. In order to examine the bioactivity of rhodium(III) complexes, studies on the interaction of rhodium(III) with pyridine-2-aldoxime [11], DL-methionine [12], L-cysteine [13], and adenosine [14] have already been reported. In the present paper we report the results on the interaction of three glycine containing dipeptides glycyl-Lalanine (L 1 -L H), glycyl-L-aspergine (L 2 -L H) and glycyl-Ltyrosine (L 3 -L H) with the title complex.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Kinetic and Mechanistic Studies on the Interaction of Glycyl‐L‐alanine, Glycyl‐L‐asparagine, and Glycyl‐L‐tyrosine with Hydroxopentaaquarhodium(III) Ion

Bera¹,

Ray²,

Mondal³

et al. 2013

Journal of Chemistry

View full text Add to dashboard Cite

The kinetics of the interaction of three glycine-containing dipeptides, namely, glycyl-L-alanine (L 1-L H), glycyl-L-asparagine (L 2-L H), and glycyl-L-tyrosine (L 3-L H) with [Rh(H 2 O) 5 OH] 2+ has been studied spectrophotometrically in aqueous medium as a function of the molar concentration of [Rh(H 2 O) 5 OH] 2+ , [dipeptide], pH, and temperature at constant ionic strength. Reactions were studied at pH 4.3, where the substrate complex exists predominantly as the hydroxopentaaqua species and dipeptides as the zwitterion. The reaction has been found to proceed via two parallel paths: both processes are ligand dependent. The rate constant for the processes are 1 ∼ 10 −3 s −1 and 2 ∼ 10 −5 s −1. The activation parameters for both the steps were evaluated using Eyring's equation. The low Δ ̸ = 1 and large negative value of Δ ̸ = 1 as well as Δ ̸ = 2 and Δ ̸ = 2 indicate an associative mode of activation for both the aqua ligand substitution processes for both the parallel paths. The product of the reaction has been characterized by IR and ESI-mass spectroscopic analyses.

show abstract

“…Thus, there is no problem in calculating both the rate constants. The 2 and are calculated in a manner similar to (11), and data are collected in Table 3.…”

Section: Ligandmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Kinetic and Mechanistic Studies on the Interaction of Glycyl‐L‐alanine, Glycyl‐L‐asparagine, and Glycyl‐L‐tyrosine with Hydroxopentaaquarhodium(III) Ion

Bera¹,

Ray²,

Mondal³

et al. 2013

Journal of Chemistry

View full text Add to dashboard Cite

show abstract

“…Thus it is expected that the direct use of the aqua complexes will have less toxic effect. In order to examine the bioactivity of rhodium(III) complexes, studies on the interaction of rhodium(III) with pyridine-2-aldoxime [10], DL-methionine [11], L-cysteine [12], and adenosine [13] have been reported. Dimeric-m-acetato dimers of Rh(II), as well as monomeric square planar Rh(I) and octahedral Rh(III) complexes, have shown interesting antitumour properties [14], and the rhodium complex (Z 5 -C 5 Me 5 )RhCl(Z 2 -C 10 H 6 N 2 O) may also be interesting as potential anticancer drugs owing to their high cytotoxicity toward cancer cell lines [15].…”

Section: Introductionmentioning

confidence: 99%

Interaction of Glycyl – Glycine with Hydroxopentaaquarhodium(Iii) Ion in Aqueous Medium: Kinetic and Mechanistic Studies

Bera

Mallick

Mandal

et al. 2011

Progress in Reaction Kinetics and Mechanism

View full text Add to dashboard Cite

The kinetics of interaction between glycyl -glycine (L -L 0 H) and [Rh(H 2 O) 5 OH] 2 þ have been studied spectrophotometrically in aqueous medium as a function of [Rh(H 2 O) 5 OH] 2 þ ], [glycyl -glycine], pH and temperature at constant ionic strength. At pH 4.3, the interaction with glycyl -glycine shows two parallel paths: both processes are ligand-dependent. The rate constant for the processes are: k 1 *10 À3 s À 1 and k 2 *10 À5 s À 1 . The activation parameters calculated from Eyring plots are: DH = 1 ¼ 26:7+0:3 kJ mol À 1 , DS = 1 ¼ À207+1 J K À1 mol À 1 , DH = 2 ¼ 92:4+1:3 kJ mol À 1 and DS = 2 ¼ À42+4 J K À1 mol À 1 . The ligand glycyl -glycine, with different donor atoms (N and O), attacks two rhodium(III) ions (Rh(III) being a borderline acid), with different reactivity. Based on the kinetic and activation parameters, an associative interchange mechanism is proposed for both interaction processes. From the temperature dependence of the outer-sphere association equilibrium constant, the thermodynamic parameters calculated are: DH 1 8 ¼ 21:8+1:9 kJ mol À 1 , DS 1 8 ¼ 124+6 J K À1 mol À 1 , DH 2 8 ¼ 12:7+0:5 kJ mol À 1 and DS 2 8 ¼ 89+2 J K À1 mol À 1 which give a negative DG8 value for both the steps at all temperatures studied, supporting the spontaneous formation of an outersphere association complex for both the parallel paths. The product of the reaction has been characterized from IR and ESI-mass spectroscopic analysis.

show abstract

Ligand Substitution Reactions at Inorganic Centers

2005

View full text Add to dashboard Cite

Displacement of aqua ligands from the hydroxopentaaquarhodium(III) ion by pyridine-2-aldoxime: A kinetic and mechanistic approach

Cited by 7 publications

References 20 publications

Kinetic and Mechanistic Studies on the Interaction of Glycyl‐L‐alanine, Glycyl‐L‐asparagine, and Glycyl‐L‐tyrosine with Hydroxopentaaquarhodium(III) Ion

Kinetic and Mechanistic Studies on the Interaction of Glycyl‐L‐alanine, Glycyl‐L‐asparagine, and Glycyl‐L‐tyrosine with Hydroxopentaaquarhodium(III) Ion

Interaction of Glycyl – Glycine with Hydroxopentaaquarhodium(Iii) Ion in Aqueous Medium: Kinetic and Mechanistic Studies

Ligand Substitution Reactions at Inorganic Centers

Contact Info

Product

Resources

About