Comments on Coupling Graphical and Regression Analyses of Ligand Effect Data

Abstract

In this paper we show how graphical analysis of ligand effect data for families of ligands should be combined with regression analysis in order to gain a more self-consistent interpretation of regression results. If a steric threshold shows up in the graphical analysis of the data for the trialkyl ligands (AR 3 ), then the threshold must show up in regression analysis of the full set of data. Similarly, the dependence of the data for the isosteric ligands A(p-XC 6 H 4 ) 3 must have the same dependence on the electronic parameter χ that we find for the regression analysis for the full set of data. Finally, graphical analysis for both AR 3 and A(p-XC 6 H 4 ) 3 families shows vividly whether steric effects and/or aryl effects belong in the full analysis. Thus, for results of any regression analysis to be acceptable, they must be consistent with the results of graphical analysis.

Organo‐Phosph(on/in)ate‐Bridged Dimers of Vanadium(IV) Complexes with the Kläui Ligand: Synthesis and Characterization

“…Results are summarized in Table 1, Table S1, and Figure S1. [11] Attempts to correlate the trends across several stereoelectronic parameters [19] show no obvious correlation with the observed electrochemical oxidations or the donor R groups on the bridging O-PRЈRЈЈ-O unit. Most dimer complexes exhibited two unique oxidation events, believed to correspond to the one electron oxidation of one metal center in the dinuclear species (namely V IV /V IV to V IV /V V ) followed by the subsequent oxidation of the second vanadium center (i.e.…”

“…Bond lengths [Å] and angles [°]: V1-O1 1.5998 (14), V1-O2 2.0038 (13), V1-O3 2.0080 (14), V1-O1p 2.2116 (13), V1-O2p 2.0256 (13), V1-O3p 2.0215 (14), P1-O1p 1.5001 (13), P2-O2p 1.5117 (13), P3-O3p 1.5190 (13), O2-C2 1.272 (2), O3-C4 1.267 (2), O1-V1-O1p 178.09 (6), O2-V1-O2p 164.25 (6), O3-V1-O3p 162.54 (6), O2-V1-O3 87.55 (5), C2-C3-C4 125.17 (18), P1-Co1-P2 89.772 (19), P1-Co1-P3 89.789(19), P2-Co1-P3 87.940(19). Hydrogen atoms are shown as circles of arbitrary size.…”

Fluoroalkenyl, fluoroalkynyl and fluoroalkyl phosphines

“…IR (KBr, neat); n 1710 (C5 5C), 1299, 1165, 998 (C-F) cm À1 . 13 3 Using a similar method to that described above using CF 3 CH 2 F (9.3 ml, 110.3 mmol) in diethyl ether (100 ml), n-BuLi (in hexanes, 88 ml, 2.5 M, 220 mmol) and SbCl 3 (6.3 g, 27.6 mmol) dissolved in Et 2 O (100 ml) resulted, after distillation (42 8C, 10 mmHg) in Sb(CF5 5CF 2 ) 3 as a clear liquid (6.85 g 70%). Anal.…”

“…These include attempts to extract information about the stereoelectronic factors that influence the thermodynamics and kinetics of reactions by quantitative analysis of ligand effects (abbreviated as QALE) [13] and attempts to generate a phosphine ligand knowledge database [14]. The approaches used, and their validity Table 1 Steric and electronic properties of some monodentate P(III) compounds.…”

Relationship of QTAIM and NOCV Descriptors with Tolman’s Electronic Parameter

“…As a prominent example, the molecular electrostatic potential at the lone pair of the phosphorus atom should be emphasized, which correlates well with TEP, according to Suresh and Koga [5]. Moreover, the method known as quantitative analysis of ligand effects (QALE) relies on experimental data of known ligands and provides the resolution of net donating ability into QALE parameters [6,7]. The second category uses approaches which focus on the entire transition metal complex, thereby including the possibility of scrutinizing ligand-ligand effects as well.…”