Related Experiment Videos
Generating and dimerizing the transient 16-electron phosphinidene complex [Cp*Ir=PAr]: a theoretical and experimental
Arjan T Termaten1, Tom Nijbacker, Andreas W Ehlers
1Department of Chemistry, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1083, 1081 HV, Amsterdam, The Netherlands.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|August 19, 2004
Summary
Researchers explored 16-electron phosphinidene iridium complexes. Steric factors drive the formation of novel fused-ring systems via intramolecular C-H bond activation, differing from related imido complexes.
Area of Science:
- Organometallic Chemistry
- Inorganic Chemistry
- Computational Chemistry
Background:
- 16-electron complexes are crucial intermediates in organometallic chemistry.
- Phosphinidene complexes are less understood compared to their imido counterparts.
Purpose of the Study:
- To investigate the properties and reactivity of 16-electron phosphinidene iridium complexes.
- To compare the behavior of phosphinidene complexes with related imido complexes.
Main Methods:
- Density Functional Theory (DFT) calculations for geometry and reaction pathways.
- Experimental synthesis and characterization of novel iridium complexes.
- ONIOM calculations to probe reaction mechanisms.
Main Results:
- DFT predicts a bent geometry for [CpIr=PH], unlike linear [CpIr=NH].
- Calculations show energetically favorable dimerization and ligand addition for phosphinidene complexes.
- Experimental dehydrohalogenation yielded novel fused-ring systems, suggesting dimeric [[Cp*Ir=PAr]2] as an intermediate.
Conclusions:
- Steric factors induce intramolecular C-H bond activation, leading to irreversible formation of fused-ring systems.
- The steric congestion in dimeric phosphinidene complexes promotes rearrangement to reactive planar structures.
- Phosphinidene iridium complexes exhibit distinct reactivity compared to imido complexes.