Crystal structure and spectroscopic characterization of a cobalt(II) tetraazamacrocycle: completing a series of first-row transition-metal complexes
Abstract
The tetraazamacrocyclic ligand 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetra-decane (TMC) has been used to bind a variety of first-row transition metals but to date the crystal structure of the cobalt(II) complex has been missing from this series. The missing cobalt complex chlorido(1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane-κ^4N)cobalt(II) chloride dihydrate, [CoCl(C_(14)H_(32)N_4)]Cl·2H_2O or [Co^(II)Cl(TMC)]Cl·2H_2O, crystallizes as a purple crystal. This species adopts a distorted square-pyramidal geometry in which the TMC ligand assumes the trans-I configuration and the chloride ion binds in the syn-methyl pocket of the ligand. The Co^(II) ion adopts an S = 3/2 spin state, as measured by the Evans NMR method, and UV–visible spectroscopic studies indicate that the title hydrated salt is stable in solution. Density functional theory (DFT) studies reveal that the geometric parameters of [Co^(II)Cl(TMC)]Cl·2H_2O are sensitive to the cobalt spin state and correctly predict a change in spin state upon a minor perturbation to the ligand environment.
Additional Information
© 2017 International Union of Crystallography. Received 29 April 2017; accepted 13 July 2017; online 20 July 2017. We thank Professor Adam Johnson (Harvey Mudd College) for helpful discussions. This work was funded by the Department of Chemistry at Harvey Mudd College, the Hixon Center for Sustainable Environmental Design at Harvey Mudd College through its Rasmussen Summer Research Fund (to CY), the Rose Hills Foundation (to IL), and the Harris Family Research Fellowship in Chemistry honoring Professor Emeritus Philip C. Myhre (to RG). This work used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation grant No. ACI-1548562.Attached Files
Published - yp3138.pdf
Supplemental Material - sendsupfiles.pdf
Supplemental Material - sendsupfiles.txt
Supplemental Material - yp3138.cif
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Additional details
- Eprint ID
- 79269
- DOI
- 10.1107/S2053229617010397
- Resolver ID
- CaltechAUTHORS:20170721-105932439
- Harvey Mudd College
- Rose Hills Foundation
- Harris Family Research Fellowship
- ACI-1548562
- NSF
- Created
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2017-07-21Created from EPrint's datestamp field
- Updated
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2021-11-15Created from EPrint's last_modified field