The Coordination Model for Non‐Aqueous Solvent Behavior

Drago, Russell S.; Purcell, Keith F.

doi:10.1002/9780470166079.ch4

Cited by 34 publications

(3 citation statements)

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“…(a) Specific interactions , which were described by Drago et al as localized donor−acceptor interactions involving specific orbitals, and parametrized via Gutman’s AN and DN scales, Drago’s E B and C B scales; and as acid−base interactions involving hydrogen bonding by Kamlet and Taft, and parametrized via Koppel and Palm’s B (MeOD), Arnett’s Δ H r scale, Kamlet and Taft’s α and β, Maria and Gal’s Δ H (BF 3 ), and Catalán and co-workers’ SA and SB scales …”

Section: Introductionmentioning

confidence: 99%

Toward a Generalized Treatment of the Solvent Effect Based on Four Empirical Scales: Dipolarity (SdP, a New Scale), Polarizability (SP), Acidity (SA), and Basicity (SB) of the Medium

2009

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This paper reports a methodology for analyzing the solvent effect from empirical measurements of solvent acidity (SA), basicity (SB), dipolarity (SdP), and polarizability (SP). The proposed methodology departs from the traditional single-parameter procedures for estimating nonspecific solvent effects by splitting them into a polarizability term and a dipolarity term. In this work, we examined the SA, SB, SP, and SdP values for 160 solvents, the gas phase (the absence of solvent) being the origin of these scales. As shown in this paper, this information allows one not only to accurately describe the solvent effect experienced by any solute whether polar or nonpolar and exhibiting some or no specific interaction with the solvent but also to understand the nature of the well-known solvent parameters E(T)(30), pi, S', and SPP, which are frequently used to describe the overall nonspecific contribution of solvents in terms of a single parameter. The high potential of the proposed empirical methodology is illustrated with its application to the solvatochromic analysis of the spectroscopic behavior of molecular chromophores, thus explaining, for example, the influence of solvent effects in the twist intramolecular charge transfer (TICT), the excited-state intramolecular proton transfer (ESIPT), or LASER (light amplification by stimulated emission of radiation) emissions. Also, this methodology is applied to understanding for the indole chromophore the feasible inversion of the electronic nature for the first electronic excited state due to solvent effects.

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Section: Introductionmentioning

confidence: 99%

Toward a Generalized Treatment of the Solvent Effect Based on Four Empirical Scales: Dipolarity (SdP, a New Scale), Polarizability (SP), Acidity (SA), and Basicity (SB) of the Medium

2009

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“…The reversible polarographic half-wave potential in a given medium gives the formal potential for the above reaction, since the diffusion coefficients are the same (18). This value has been shown to be --0.35V in a methanolic solution containing 0.02M HC1 and 0.18M LiC1.…”

Section: Napp--]ianod[-~ [Icath[mentioning

confidence: 99%

“…From the above rationale, we know that both Ti(III) and Ti(IV) have the same number of chloride ligands, but we are unable to say if all ligands are chloride or only some chloride ions are present, with solvent molecules playing an important role in the coordination sphere. The fact that methanol is a strong base towards first row transition metals [as shown by a number of previous studies (18)] suggests that methanol could compete quite successfully with chloride ion as a coordinating ]igand. We thus speculate that both titanium species have methanol and chloride ion coordinated in the complex in the "anhydrous" solutions, but the data we have available at present do not permit detailed elucidation of the nature of the titanium species.…”

Section: Napp--]ianod[-~ [Icath[mentioning

confidence: 99%

Effect of Chloride on the Anodic Dissolution of Titanium in Methanolic Solutions

Parry¹,

Hern²

1972

J. Electrochem. Soc.

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A study of the polarographic characteristics of the Ti(IV)‐Ti(III) couple in methanolic solutions containing various concentrations of normalHCl and normalLiCl has been the basis for the determination of the oxidation state of titanium during dissolution in these media. The Ti(IV) and Ti(III) complexes have been shown to have the same number of chloride ligands. It is also shown that titanium dissolves with an apparent oxidation number (n app) between 3 and 4, with the value approaching 3 at high chloride concentrations. The acidity appears to have little effect at acidities greater than 0.10M. It is also shown that Ti(IV) in methanol solutions containing a high chloride ion concentration oxidizes Ti to form Ti(III). The nature of the complexes of titanium ion in solution and their effect on the titanium dissolution is discussed.

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Nucleophile Reaktivität der Thiophosphoryl‐Gruppe

Teichmann¹,

Hilgetag²

1967

Angewandte Chemie

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\ \ / Die unterschiedliche nucleophile Reaktivitat der ,P=S-und P-0-Gruppe lapt sich bejriedigend nach Pearsons Saure-Base-Konzeption [211 verstehen. Als typische ,,weiche Ruse" reagiert der ThiophosphoryESch wefel bevorzugt mit B-Metallen, Halogenen und sp3-hybridisiertem Kohlenstofi gegenuber ,,harten Sauren" wie Protonen, Carbonyl-Kohlenstoff und tetraedrischem Phosphor zeigt er sich dagegen weitgehend indifferent. Da eine nucleophile Betutigung des Thiophosphoryl-Schwefels die Ladungsdichte am Phosphoratom verringert, wird diesesoder bei 0-Alkylestern das u-Kohlenstoffatomeinem nucleophilen Angriff leichter zuganglich. Schwejelaustausch, Entalkylierung, Isomerisierung, Pistschimuka-und Michalski-Reaktton srnd Resultate dieses Reaktionsprinzips. 3. im verglichen mit der P=O-Bindung geringeren x-Bindungsanteil der P=S-Bindung. Dies folgt aus den Valenzkraftkonstanten [61, den unterschiedlichen Kiirzungen der Bindungslangen [TI, der Differenz zwischen den Dissoziationsenergien der PX-Einfach-und Doppelbindungen [81, der Elektronegativitats-Differenz zwischen P und X [91 sowie aus den 31P-NMR-Signalen, die fur (lb) stets bei niedrigerem Feld liegen als fur (In) [10,111.Die P=O-Bindung ist als semipolare Bindung aufzufassen, der sich durch Riickgabe von p-Elektronen des Sauerstoff-Atoms in unbesetzte d-Orbitale des Phosphor-Atoms eine p,-d,-Bindung iiberlagert; da die uberlappung der pund d-Orbitale ihr Maximum nahe dem Sauerstoff-Atom hat, ist die p,-d,-Bindung der P=O-Gruppe vie1 starker polar als die in der Kohlenstoff-Chemie ublichen p,-p,-Bindungen [121.Die p,-d,-Wechselwirkung und damit der P=O-Bindungsgrad nimmt mit steigender Elektronegativitat der Substituenten A, B, C zu; sehr deutlich driickt sich dies in der Lage der PO-Frequenz aus, die linear von der Elektronegativitaten-Summe der Substituenten A, B und C abhangt[13.141. Berechnungen des P=O-Bindungsgrades liefern je nach Methode unterschiedliche Werte, die aber den gleichen Gang zeigen.

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The Coordination Model for Non‐Aqueous Solvent Behavior

Cited by 34 publications

References 97 publications

Toward a Generalized Treatment of the Solvent Effect Based on Four Empirical Scales: Dipolarity (SdP, a New Scale), Polarizability (SP), Acidity (SA), and Basicity (SB) of the Medium

Toward a Generalized Treatment of the Solvent Effect Based on Four Empirical Scales: Dipolarity (SdP, a New Scale), Polarizability (SP), Acidity (SA), and Basicity (SB) of the Medium

Effect of Chloride on the Anodic Dissolution of Titanium in Methanolic Solutions

Nucleophile Reaktivität der Thiophosphoryl‐Gruppe

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