Premium
What governs nitrogen configuration in substituted aminophosphines?
Author(s) -
Wodrich Matthew D.,
Vargas Alfredo,
Morgantini PierreYves,
Merino Gabriel,
Corminboeuf Clémence
Publication year - 2009
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.1431
Subject(s) - chemistry , lone pair , delocalized electron , nitrogen atom , nitrogen , valence electron , computational chemistry , electron localization function , atom (system on chip) , valence (chemistry) , wave function , electron pair , crystallography , electron , atomic physics , molecule , organic chemistry , quantum mechanics , group (periodic table) , physics , computer science , embedded system
The trigonal planar geometry of the nitrogen atom in commonly used phosphoramidite ligands is not in line with the traditional valence shell electron pair repulsion (VSEPR) model. In this work, the effects governing nitrogen configuration in several substituted aminophosphines, A 2 PNB 2 (A or B = H, F, Cl, Br, Me, OMe, BINOP), are examined using modern computational analytic tools. The electron delocalization descriptions provided by both electron localization function (ELF) and block localized wavefunction analysis support the proposed relationships between conformation and negative hyperconjugative interactions. In the parent H 2 PNH 2 , the pyramidal nitrogen configuration results from nitrogen lone pair electron donation into the σ * PH orbital. While enhanced effects are seen for F 2 PNMe 2 , placing highly electronegative fluorine substituents on nitrogen (i.e., Me 2 PNF 2 ) eliminates delocalization of the nitrogen lone pair. Understanding and quantifying these effects can lead to greater flexibility in designing new catalysts. Copyright © 2008 John Wiley & Sons, Ltd.