Infrared studies of water bound to some extracted phenanthroline and phenanthroline chelates

Burchett, Stuart; Meloan, Clifton E.

doi:10.1016/0022-1902(72)80321-x

Cited by 20 publications

(4 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The second band centered at 3400 cm-1 is indicative of He O coordinated to the metal cation and hydrogen bonded to other H20 molecules in the second coordination sphere (Farmer and Russell, 1967). Other workers have also observed a band near 3400cm -1 and attributed it to H20 weakly coordinated to Fe(II) in Fe(phen) 2 + which had been dissolved in nitromethane solutions (Burchett and Meloan, 1972). If a model of the Fe(phen) 2 + hectorite is considered in which the complex cations are separated by a distance of about 12 A, and adsorbed water could be bound to either the silicate surface or to the metal nucleus of the complex ion, the latter being more energetic.…”

Section: Adsorption Of Water and Benzenementioning

confidence: 94%

Hectorite Complexes with Cu(II) and Fe(II)-1,10-Phenanthroline Chelates

Berkheiser

1977

Clays and clay miner.

View full text Add to dashboard Cite

Abstract--Characteristics and properties of complexes of a smectite (hectorite) with 1,10-phenanthroline (phen) chelates with iron or copper were determined by a variety of physical and chemical measurements. The complex ions showed high selectivity for the hectorite surface. Basal spacings of 17.4 A were produced by Fe(II) or Cu(II) analogues of M(phen) 2 + hectorite. Adsorption of gases and vapors by the M(phen)~ § hectorite complex revealed large surface areas and reflected intrinsic characteristics of the complex ions. Lower surface areas were found for copper phen hectorite than iron phen hectorite probably because of the loss of a ligand from the Cu(II) ion. ESR spectra confirmed that appreciable Cu(ll) existed as the bis-phen complex under certain conditions. An increase in the oxidation potential of the Fe(phen)~ + Fe(phen)~ + couple above that in pure solvent was noted when these complexes were supported by the mineral surface.

show abstract

Section: Adsorption Of Water and Benzenementioning

confidence: 94%

Hectorite Complexes with Cu(II) and Fe(II)-1,10-Phenanthroline Chelates

Berkheiser

1977

Clays and clay miner.

View full text Add to dashboard Cite

show abstract

“…A possible explanation for the observed decrease in rate would be coordination of a water molecule by nucleophilic attack at the carbon atom adjacent to the ring nitrogen of the iron(III) polypyridyl complexes (Eqn 1) at higher concentrations making them inactive towards oxidation. [24] The coordination of water to metal polypyridyl complexes was proved by Burchett and Meloan [25] by infrared studies and the possibility of attack of water at 2 and 9 positions was shown by Schmid and Han [26] using CNDO calculations. The formation of 1 during the course of the reaction in a parallel reaction is ascertained by the tremendous magnitude of rate retardation observed with complex 1e, containing electron-withdrawing group (EWG), than other complexes.…”

Section: Resultsmentioning

confidence: 99%

A paradigm shift in rate determining step from single electron transfer between phenylsulfinylacetic acids and iron(III) polypyridyl complexes to nucleophilic attack of water to the produced sulfoxide radical cation: a non‐linear Hammett

Subramaniam¹,

Rose

Rathinakumari

2016

J of Physical Organic Chem

View full text Add to dashboard Cite

Mechanism of oxidative decarboxylation of phenylsulfinylacetic acids (PSAAs) by iron(III) polypyridyl complexes in aqueous acetonitrile medium has been investigated spectrophotometrically. 3+ is rationalized on the basis of coordination of a water molecule at the carbon atom adjacent to the ring nitrogen of the metal polypyridyl complexes by nucleophilic attack at higher concentrations. Electron-withdrawing and electron-releasing substituents in PSAA facilitate the reaction and Hammett correlation gives an upward 'V' shaped curve. The apparent upward curvature is rationalized based on the change in the rate determining step from electron transfer to nucleophilic attack, by changing the substituents from electron-releasing to electron-withdrawing groups. Electron-releasing substituents in PSAA accelerate the electron transfer from PSAA to the complex and also stabilize the intermediate through resonance interaction leading to negative reaction constants (ρ). Conversely, electron-withdrawing groups, while retarding the electron transfer exert an accelerating effect on the nucleophilic attack of H 2 O which leading to low magnitude of ρ + compared to high ρ À values of electron-releasing groups. Marcus theory is applied, and a fair agreement is seen with the experimental values.

show abstract

“…x" 2 (26) and for the inner-and outer-sphere terms, (29) should be related to X¡ for reactions 9 The oxo-bridged ion [(bpy)2ClRuORuCl(bpy)2]2+ has multiple redox properties and is delocalized.26 In contrast to pyrazine as a bridge, there is strong coupling between ruthenium ions across the bridging oxide ion and the redox properties are carried by orbitals which are delocalized over both ruthenium ions. Taube and his co-workers have shown that in related systems the resonance energy is sufficiently high across bridging dinitrogen (e.g., in czí-[(NH3)4C10s(N2)- Taube ion,6-7 but a truly satisfactory description of the oxidation state properties of the ion has not been given.…”

Section: /3mentioning

confidence: 99%