Conformational analysis of triphenylphosphine ligands in stereogenic monometallic complexes: Tools for predicting the preferred configuration of the triphenylphosphine rotor

Gould, Elliott T.F.; Costello, James F.; Davies, Stephen G.; Gould, Elliot; Thomson, James E.

Abstract

© The Royal Society of Chemistry 2015. The extension of our simple model for predicting the propeller configuration of a triphenylphosphine ligand co-ordinated to achiral metal centres to include stereogenic metal systems is described. By considering nadir energy planes (NEP's) and a series of rigid-body calculations, a model has been developed to reliably predict the configuration of the triphenylphosphine rotor of stereogenic metal complexes. For complexes of the form [M(η 5 -C 5 H 5 )(PPh 3 )(L 1 )(L 2 )], where it is assumed that L 1 is larger than L 2 , the configuration of the triphenylphosphine rotor may be predicted by viewing a Newman projection along the L 1 -M bond. In the orientation where the PPh 3 unit is pointing vertically downwards and the orthogonal L 2 ligand is pointing to the right [i.e., an (R M )-configured complex, assuming that L 2 is ranked higher priority than L 1 ], the conformation of L 1 can be expected to place the most sterically demanding substituent in the top-right quadrant. In cases where ligand L 1 still presents a steric incursion towards the PPh 3 ligand (any part of L 1 other than H proximal to the PPh 3 in the approximate zone -30° to +60° from the M-P bond) an (M)-configured rotor is expected, and when this interaction is not present a (P)-configured propeller is predicted. Without exception, these rules are consistent with all empirical data (>140 known crystal structures). This journal is

• Journal Article Type: Article
• Publication Date: Mar 28, 2015
• Deposit Date: Mar 4, 2015
• Journal: Dalton Transactions
• Print ISSN: 1477-9226
• Electronic ISSN: 1477-9234
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 44
• Issue: 12
• Pages: 5451-5466
• DOI: https://doi.org/10.1039/c5dt00250h
• Keywords: triphenylphosphine ligands, stereogenic monometallic complexes, triphenylphosphine rotor
• Public URL: https://uwe-repository.worktribe.com/output/836981
• Publisher URL: http://dx.doi.org/10.1039/c5dt00250h
• Additional Information: Additional Information : First published online 6 Feb 2015
• Contract Date: Mar 2, 2016