Next Article in Journal
Hydrogen Sorption in Erbium Borohydride Composite Mixtures with LiBH4 and/or LiH
Next Article in Special Issue
Hetero- and Homoleptic Magnesium Triazenides
Previous Article in Journal / Special Issue
Methanediide Formation via Hydrogen Elimination in Magnesium versus Aluminium Hydride Complexes of a Sterically Demanding Bis(iminophosphoranyl)methanediide
Article Menu
Issue 2 (June) cover image

Export Article

Open AccessArticle
Inorganics 2017, 5(2), 30; doi:10.3390/inorganics5020030

Backbone-Substituted β-Ketoimines and Ketoiminate Clusters: Transoid Li2O2 Squares and D2-Symmetric Li4O4 Cubanes. Synthesis, Crystallography and DFT Calculations

1
Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, AB T1K3M4, Canada
2
The Canadian Centre for Research in Advanced Fluorine Technologies, University of Lethbridge, Lethbridge, AB T1K3M4, Canada
*
Author to whom correspondence should be addressed.
Academic Editor: Matthias Westerhausen
Received: 31 March 2017 / Revised: 21 April 2017 / Accepted: 21 April 2017 / Published: 26 April 2017
(This article belongs to the Special Issue s-Block Metal Complexes)
View Full-Text   |   Download PDF [6358 KB, uploaded 26 April 2017]   |  

Abstract

The preparation and crystal structures of four β-ketoimines with bulky aryl nitrogen substituents (2,6-diisopropylphenyl and 2,4,6-trimethylphenyl) and varying degrees of backbone methyl substitution are reported. Backbone substitution “pinches” the chelate ring. Deprotonation with n-butyllithium leads to dimeric Li2O2 clusters, as primary laddered units, with an open transoid geometry as shown by crystal structures of three examples. The coordination sphere of each lithium is completed by one tetrahydrofuran ligand. NMR spectra undertaken in either C6D6 or 1:1 C6D6/d8-THF show free THF in solution and the chemical shifts of ligand methyl groups experience significant ring-shielding which can only occur from aryl rings on adjacent ligands. Both features point to conversion to higher-order aggregates when the THF concentration is reduced. Recrystallization of the materials from hydrocarbon solutions results in secondary laddering as tetrameric Li4O4 clusters with a cuboidal core, three examples of which have been crystallographically characterised. These clusters are relatively insoluble and melt up to 250 °C; a consideration of the solid-state structures indicates that the clusters with 2,6-diisopropylphenyl substituents form very uniform ball-like molecular structures that will only be weakly solvated. View Full-Text
Keywords: β-ketoimine; β-ketoiminate; lithiation; high-nuclearity clusters; crystallography; DFT calculations; X-ray crystallography; multinuclear NMR; primary laddered units; secondary laddering β-ketoimine; β-ketoiminate; lithiation; high-nuclearity clusters; crystallography; DFT calculations; X-ray crystallography; multinuclear NMR; primary laddered units; secondary laddering
Figures

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Supplementary material

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Gietz, T.; Boeré, R.T. Backbone-Substituted β-Ketoimines and Ketoiminate Clusters: Transoid Li2O2 Squares and D2-Symmetric Li4O4 Cubanes. Synthesis, Crystallography and DFT Calculations. Inorganics 2017, 5, 30.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Inorganics EISSN 2304-6740 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top