TY - JOUR
T1 - Comparing spectroscopic and electrochemical properties of complexes of type Cp'M(η3-C3H5)(CO)2 (Cp' = Cp, Ind, Flu)
T2 - A complementary experimental and DFT study
AU - Gonçalves, Isabel S.
AU - Veiros, Luís F.
AU - Gamelas, Carla A.
AU - Cabrita, Clara
AU - Calhorda, Maria José
AU - Geraldes, Carlos F. G. C.
AU - Green, Jennifer
AU - Packham, Ellen
AU - Drew, Michael G. B.
AU - Félix, Vitor
AU - Santos, António Gil de Oliveira
AU - Romão, Carlos C. R. Crispim
N1 - We thank the Fundacao para a Ciencia e Tecnologia, Portugal, for financial support (Projects UID/QUI/00100/2013 and UID/MULTI/00612/2013). We are grateful to the Fundacao para a Ciencia e Tecnologia (FCT), QREN, Fundo Europeu de Desenvolvimento Regional (FEDER), COMPETE, and the European Union, for the Associate Laboratory CICECO FCOMP-01-0124-FEDER-037271 (FCT ref. PEst-C/CTM/LA0011/2013) and FCOMP-01-0124-FEDER-029779 (FCT ref. PTDC/QEQ-SUP/1906/2012). The nuclear magnetic resonance spectrometers are part of the National NMR Network and were purchased in the framework of the National Program for Scientific Re-equipment, contract REDE/1517/RMN/2005, with funds from POCI 2010 (FEDER) and Fundacao para a Ciencia e a Tecnologia. We thank Elke Hunstock for preliminary calculations.
PY - 2015/8/10
Y1 - 2015/8/10
N2 - Abstract A series of allyl complexes of the general formula [Cp'Mo(η3-C3H5)(CO)2], where Cp' = Cp, CpMe, Cp∗, Ind, IndMe, IndMe2, Flu, and three tungsten analogues, has been prepared and characterized by 1H, 13C, and 95Mo NMR, cyclic voltammetry, and the structure of [IndMo(η3-C3H5)(CO)2] was determined by X-ray single crystal analysis. Two conformers, corresponding to the two extreme orientations of the allyl ligand (endo and exo), have been identified in solution by 1H and 95Mo NMR for all the complexes, except for [FluMo(η3-C3H5)(CO)2], which only presents an exo conformation in solution. A 95Mo NMR investigation also shows the influence of electron donor capability of the Cp' ligands on the 95Mo chemical shifts of the Mo center. He I and He II photoelectron spectra probe the electron richness of the metal center and the electronic structure of the complexes. Cyclic voltammetry studies show one oxidation process, which is only reversible for the Cp derivatives. DFT calculations provided a reliable way to determine ionization energies, and reflected very well the trends of the other properties, from the 95Mo NMR chemical shifts, to vibration frequencies, and oxidation potentials.
AB - Abstract A series of allyl complexes of the general formula [Cp'Mo(η3-C3H5)(CO)2], where Cp' = Cp, CpMe, Cp∗, Ind, IndMe, IndMe2, Flu, and three tungsten analogues, has been prepared and characterized by 1H, 13C, and 95Mo NMR, cyclic voltammetry, and the structure of [IndMo(η3-C3H5)(CO)2] was determined by X-ray single crystal analysis. Two conformers, corresponding to the two extreme orientations of the allyl ligand (endo and exo), have been identified in solution by 1H and 95Mo NMR for all the complexes, except for [FluMo(η3-C3H5)(CO)2], which only presents an exo conformation in solution. A 95Mo NMR investigation also shows the influence of electron donor capability of the Cp' ligands on the 95Mo chemical shifts of the Mo center. He I and He II photoelectron spectra probe the electron richness of the metal center and the electronic structure of the complexes. Cyclic voltammetry studies show one oxidation process, which is only reversible for the Cp derivatives. DFT calculations provided a reliable way to determine ionization energies, and reflected very well the trends of the other properties, from the 95Mo NMR chemical shifts, to vibration frequencies, and oxidation potentials.
KW - 95Mo NMR
KW - Allyl complexes
KW - DFT calculations
KW - Molybdenum
KW - PES spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=84938996548&partnerID=8YFLogxK
U2 - 10.1016/j.jorganchem.2015.04.001
DO - 10.1016/j.jorganchem.2015.04.001
M3 - Article
AN - SCOPUS:84938996548
SN - 0022-328X
VL - 792
SP - 154
EP - 166
JO - Journal of Organometallic Chemistry
JF - Journal of Organometallic Chemistry
M1 - 18984
ER -