Journal article
The indenyl effect on d0 organotransition metal complex LMCT luminescence: Synthesis, structural characterization, cyclic voltammetry, spectroscopic studies, and TD-DFT computations on (η5-permethylindenyl)tetrachlorotantalum(V), and comparison to (η5-pentamethylcyclopentadienyl)tetrachlorotantalum(V)
Polyhedron, Vol.264, 117215
12/01/2024
DOI: 10.1016/j.poly.2024.117215
Abstract
The first Group 5 transition metal permethylindenyl complex, (η5-C9Me7)TaCl4, was prepared by metathesis of TaCl5 with the new reagent (C9Me7)SnBu3 and has a four-legged piano stool structure. CV and NMR data are presented. Its UV/vis LMCT absorption in toluene is substantially red-shifted from that of (η5-C5Me5)TaCl4, which is explained through time-dependent DFT.
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The new organotantalum(V) chloride (η5-permethylindenyl)tetrachlorotantalum, Ind*TaCl4, was prepared by addition of previously-unreported Ind*SnBu3 to TaCl5 in toluene at 70° in 53 % isolated yield. The solid-state four-legged piano-stool structure, consistent with solution multinuclear NMR spectroscopies, demonstrated that tantalum is bonded to all carbons of the five-membered ring of the permethylindenyl ligand, with little deviation in the Ta-C distances. The permethylindenyl ring torsional angles for the three independent molecules in the unit cell vary from 2.46(17)° to 5.10(17)°. The cyclic voltammogram of Ind*TaCl4 in tetrahydrofuran showed one reversible reduction feature at −1.24 V [Ta(V)/Ta(IV)] and one quasi-reversible reduction feature at −1.65 V [Ta(IV)/Ta(III)] vs. Fc/Fc+. The UV/vis LMCT absorption λmax at 593 nm (ε = 2000 M−1 cm−1) in toluene is remarkably red-shifted from that of the known η5-pentamethylcyclopentadienyl analog, luminescent-yellow Cp*TaCl4. TD-DFT calculations were used to explain the comparative UV/vis absorption spectra.
Details
- Title: Subtitle
- The indenyl effect on d0 organotransition metal complex LMCT luminescence: Synthesis, structural characterization, cyclic voltammetry, spectroscopic studies, and TD-DFT computations on (η5-permethylindenyl)tetrachlorotantalum(V), and comparison to (η5-pentamethylcyclopentadienyl)tetrachlorotantalum(V)
- Creators
- Grant E. ForsytheGabriel J. SmithDale C. SwensonJames J. ShepherdLouis Messerle
- Resource Type
- Journal article
- Publication Details
- Polyhedron, Vol.264, 117215
- DOI
- 10.1016/j.poly.2024.117215
- ISSN
- 0277-5387
- eISSN
- 1873-3719
- Publisher
- Elsevier Ltd
- Grant note
The authors thank the reviewers whose constructive comments improved the manuscript and resulted in calculations for Fig. 7. G. Forsythe thanks the University of Iowa Department of Chemistry for financial support. We thank Nathan C. Stumme and Scott K. Shaw for performing CV experiments and J. Earl for help with analysis of the CIF file for Cp*TaCl4. G. Smith gratefully acknowledges Emily Campbell for training and mentorship. We thank D. Unruh for help with the checkcif modifications for H -atom positions in the final CIF. The Enraf-Nonius CAD-4 X-ray diffractometer with Bruker APEX II CCD detector up-grade and the Exeter Analytical CE440 elemental analyzer were pur-chased and supported by grants from the Roy J. Carver Charitable Trust.
- Language
- English
- Electronic publication date
- 08/31/2024
- Date published
- 12/01/2024
- Academic Unit
- Radiology; Chemistry
- Record Identifier
- 9984701408502771
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