Covalent bonding and the trans influence in lanthanide compounds
Karsten Krogh-Jespersen1, Michael D Romanelli, Jonathan H Melman
1Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08903, USA. kroghjes@rci.rutgers.edu
Inorganic Chemistry
|December 23, 2009
Summary
New lanthanide chalcogenolate coordination complexes exhibit geometry-dependent bond lengths. This difference arises from covalent interactions between lanthanide and chalcogenide elements, as confirmed by DFT calculations.
Area of Science:
- Coordination Chemistry
- Organometallic Chemistry
- Materials Science
Background:
- Lanthanide chalcogenolate complexes are of interest due to their unique electronic and structural properties.
- Understanding the factors influencing metal-ligand bond lengths is crucial for designing new materials.
Purpose of the Study:
- To synthesize and structurally characterize novel mer-octahedral lanthanide chalcogenolate coordination complexes.
- To investigate the origin of geometry-dependent bond length variations in these complexes.
Main Methods:
- Isolation and single-crystal X-ray diffraction of [(THF)(3)Ln(EC(6)F(5))(3)] complexes (Ln = Er, E = Se; Ln = Yb, E = S).
- Density functional theory (DFT) calculations to analyze electronic structure and bonding.
Main Results:
- Two mer-octahedral lanthanide chalcogenolate complexes were successfully synthesized and characterized.
- Observed significant differences in Ln-E bond lengths, dependent on the trans ligand (THF vs. EC(6)F(5)).
- DFT calculations revealed covalent interactions involving ligand p and Ln 5d orbitals as the cause of the trans influence.
Conclusions:
- The study elucidates the structural and electronic properties of novel lanthanide chalcogenolate complexes.
- Geometry-dependent bond lengths are attributed to a trans influence originating from covalent Ln-E interactions.
- These findings contribute to the fundamental understanding of bonding in lanthanide coordination compounds.
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