A contribution to the coordination chemistry of 2,3,5,6-tetrakis(alpha-pyridyl)pyrazine (TPP): Synthesis, spectroscopy, electrochemistry, and density-functional study of {[MO(CO)(4)](2)(mu-TPP)}

A contribution to the coordination chemistry of 2,3,5,6-tetrakis(alpha-pyridyl)pyrazine (TPP): Synthesis, spectroscopy, electrochemistry, and density-functional study of {[MO(CO)(4)](2)(mu-TPP)}

Autor Bitzer, R. S. Google Scholar
Pereira, R. P. Google Scholar
Rocco, A. M. Google Scholar
Lopes, JGS Google Scholar
Santos, P. S. Google Scholar
Nascimento, MAC Google Scholar
Filgueiras, CAL Google Scholar
Instituição Universidade Federal do Rio de Janeiro (UFRJ)
Universidade Federal de São Paulo (UNIFESP)
Resumo The reaction between CiS-[Mo(CO)(4)(Piperidine)(2)] and 2,3,5,6-tetrakis(alpha-pyridyl)pyrazine (TPP) in the 3:1 (Mo:TPP) stoichiometric ratio afforded the organobimetallic compound {[Mo(CO)(4)](2)(mu L-TPP)} (1) in 89% yield. This complex has been characterized by elemental and thermogravimetric analyses, vibrational (FT-IR and FT-Raman) and electronic spectroscopy, and H-1 and C-13-CP/MAS NMR spectroscopy. NMR data have revealed that TPP coordinates to each metal at two adjacent pyridine nitrogen atoms, according to a rare bis-bidentate chelating mode. the cyclic voltammogram of 1 in DMF has shown an irreversible metal-based oxidation at +0.77 V versus SCE. A DFT/B3LYP study of two plausible molecular structures for 1 has been carried out in vacuum using the LACV3P(d,p) and LACV3P++(d,p) basis sets. This theoretical study has pointed to the structure with the MO(CO)4 moieties on opposite sides with respect to the pyrazine ring (trans isomer - C-2h symmetry) as the most stable one. the vibrational frequencies of the trans structure have been calculated at the B3LYP/LACV3P(d,p) level and compared with the FT-IR and FT-Raman spectra of 1. An excellent agreement between experimental and calculated frequencies was obtained. (c) 2006 Elsevier B.V. All rights reserved.
Palavra-chave density functional theory
bimetallic complexes
molybdenum
nitrogen heterocyclic ligand
tetra(alpha-pyridyl)pyrazine
TPP
Idioma Inglês
Data de publicação 2006-04-15
Publicado em Journal of Organometallic Chemistry. Lausanne: Elsevier Science Sa, v. 691, n. 9, p. 2005-2013, 2006.
ISSN 0022-328X (Sherpa/Romeo, fator de impacto)
Publicador Elsevier B.V.
Extensão 2005-2013
Fonte http://dx.doi.org/10.1016/j.jorganchem.2005.12.055
Direito de acesso Acesso restrito
Tipo Artigo
Web of Science WOS:000236929300026
Endereço permanente http://repositorio.unifesp.br/handle/11600/28849

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