O–H and (CO)N–H bond weakening by coordination to Fe(ii)

Autor: Noelia Fuentes, Diego J. Cárdenas, Luis Crovetto, Luis Lezama, Víctor Blanco, Juan M. Cuerva, Sandra Resa, Alba Millán, M. Luisa Marcos, Araceli G. Campaña, Duane Choquesillo-Lazarte
Přispěvatelé: Ministerio de Economía y Competitividad (España), Junta de Andalucía, European Commission, Consejo Superior de Investigaciones Científicas (España)
Rok vydání: 2019
Předmět:
Zdroj: Digital.CSIC. Repositorio Institucional del CSIC
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ISSN: 1477-9234
1477-9226
DOI: 10.1039/c8dt04689a
Popis: New N,N′-dimethyl-N,N′-bis(2-pyridylmethyl)-ethane-1,2-diamine derivatives bearing covalently linked OH and (CO)NH groups have been synthesized. The coordination of those pendant hydroxyl/amide groups to a Fe(ii) metal center is demonstrated both in solution, even in the presence of chloride as the counterion, and in solid state, by means of X-ray diffraction crystal structures. As a result of this coordination, the experimental bond dissociation free energies (BDFE) of O-H and (CO)N-H bonds are remarkably diminished down to 76.0 and 80.5 kcal mol respectively, which is also in agreement with DFT-based theoretical calculations. These BDFE values are in the range of commonly used hydrogen-atom donor reagents. The strategy presented here allows an unequivocal evaluation of the influence of metal coordination in X-H bond weakening in organic solvents which could be easily extended to other metal centers.
We thank the Ministerio de Economía y Competitividad (MINECO, Spain) (CTQ2014-53598-R) and Junta de Andalucía (FQM2012-790). S. R. thanks the MECD for FPU predoctoral fellowship. A. M. and A. G. C. thank the MINECO for IJCI-2016-27793 and RyC-2013-12943 contracts.
Databáze: OpenAIRE