Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Assessing the stereoelectronic properties of pyrrolyl phosphines and related ligands. The quantitative analysis of ligand effects (QALE)
Autore:
Fernandez, A; Reyes, C; Lee, TY; Prock, A; Giering, WP; Haar, CM; Nolan, SP;
Indirizzi:
Boston Univ, Metcalf Ctr Sci & Engn, Dept Chem, Boston, MA 02215 USA Boston Univ Boston MA USA 02215 i & Engn, Dept Chem, Boston, MA 02215 USA Univ New Orleans, Dept Chem, New Orleans, LA 70148 USA Univ New Orleans New Orleans LA USA 70148 Chem, New Orleans, LA 70148 USA
Titolo Testata:
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2
fascicolo: 7, , anno: 2000,
pagine: 1349 - 1357
SICI:
1470-1820(2000):7<1349:ATSPOP>2.0.ZU;2-P
Fonte:
ISI
Lingua:
ENG
Soggetto:
ENTHALPY-ENTROPY RELATIONSHIP; METAL-CARBONYL CLUSTERS; UNIMOLECULAR REACTION SYSTEMS; STATISTICAL-MECHANICAL MODEL; PI-ACCEPTOR CHARACTER; ISOKINETIC RELATIONSHIP; SUBSTITUTION-REACTIONS; EXPLORING STEREOSELECTIVITY; PHOSPHORUS(III) LIGANDS; L(2)FE(CO)(3) SYSTEM;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
68
Recensione:
Indirizzi per estratti:
Indirizzo: Prock, A Boston Univ, Metcalf Ctr Sci & Engn, Dept Chem, Boston, MA 02215 USA Boston Univ Boston MA USA 02215 Dept Chem, Boston, MA 02215 USA
Citazione:
A. Fernandez et al., "Assessing the stereoelectronic properties of pyrrolyl phosphines and related ligands. The quantitative analysis of ligand effects (QALE)", J CHEM S P2, (7), 2000, pp. 1349-1357

Abstract

By application of the QALE model (quantitative analysis of ligand effects)to the standard reduction potentials (E degrees values) and the standard enthalpies of reduction (Delta H degrees) of the eta-Cp(CO)(PZ(3))Fe(COMe)(+/0) couple (PZ(3)= a phosphorus(III) ligand), and nu(CO) for eta-Cp(CO)(PZ(3))Fe(COMe)(0), we have determined that a minimum of four parameters are necessary to describe the stereoelectronic properties of the set of ligands PPhi(Pyr)(3-i) (Pyr = pyrrolyl) and P(NC4H8)(3) (NC4H8=pyrrolidinyl). These parameters are chi(d), theta, E-ar and the pi acidity parameter, pi(p). Thevalues of these parameters were determined by linear regression analysis of a set of QALE equations. The coefficients of these equations were based on the analyses of data for PR3, PPhiR3-i, P(p-XC6H4)(3), P(OR)(3), and P(O-p-XC6H4)(3). The parameters for P(Pyr)(3) are chi(d)=31.9 +/- 0.7, theta=145 +/- 3, E-ar=3.3 +/- 0.2 and pi(p)=1.9 +/- 0.2; and for P(NC4H8)(3) the parameters are chi(d)=-1.2 +/- 1.4, theta=145 +/- 5, E-ar=-0.6 +/- 0.4 and pi(p)=0.9 +/- 0.3. P(Pyr)(3) is a poor sigma donor that possesses an E-ar parameter comparable to P(p-XC6H4)(3) and a pi acidity that is about two thirds that of P(OR)(3) and half that of P(O-p-XC6H4)(3). On the other hand, P(NC4H8)(3), which is one of the strongest sigma donor phosphorus(III) ligands, is a weak pi acid with a value for E-ar that is statistically indistinguishable from zero. PPhi(Pyr)(3-i) and P(NC4H8)(3) appear to be isosteric to P(p-XC6H4)(3).

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 28/01/21 alle ore 07:38:45