The synthesis and solid state structures of homo- and heteroleptic Zr and Ti complexes of 2-(diphenylphosphino)pyrrolide (NP) are reported. The homoleptic Zr(NP)4 (1) and Ti(NP)4 (2) are 8-coordinate in the solid state, and both show extremely long M-P bonds of approximately 2.9 Å. In solution, the phosphine ligands in all complexes are labile: in the titanium complexes phosphine dissociation is rapid at room temperature and equilibrates all phosphines into a single 31P resonance, whereas in the Zr complex 1 dissociation is slower and full equilibration does not occur until 90 °C. The potential to utilize these novel complexes as metalloligands toward other transition metals is discussed.
Bibliographical noteFunding Information:
Financial support was provided by the University of Minnesota (start up funds). A.H.R. acknowledges funding from the University of Minnesota Undergraduate Research Opportunities Program (UROP) and the Department of Chemistry Heisig/Gleysteen Undergraduate Research Program . The Bruker-AXS D8 Venture diffractometer was purchased through a grant from NSF /Ministry of Research and Innovation (1224900) and the University of Minnesota. Equipment purchases for the NMR facility were supported through a grant from the NIH (S10OD011952) with matching funds from the University of Minnesota. We thank Dr. Letitia Yao (UMN) for assistance with variable temperature NMR experiments and Dr. Samantha MacMillan (Cornell) for helpful discussions.
© 2014 Elsevier B.V. All rights reserved.
- Group 4 metal
- Phosphine ligand
- Variable temperature
- X-ray crystallography