Synthesis and electrochemical studies of η5-monocyclopentadienylruthenium(II) complexes with substituted thiophene nitrile ligands. Crystal structure of [Ru(η5-C5H5)(dppe)(NC{SC4H2}2NO2)][PF6]

Benzo[c]thiophene Chromophores Linked to Cationic Fe and Ru Derivatives for NLO Materials: Synthesis Characterization and Quadratic Hyperpolarizabilities

“…The resonances are in the range usually observed for monocationic ruthenium(II) and iron(II) complexes. The same general behaviour of the NMRresonanceshasbeenobservedpreviouslyinrelatedoligothiophene iron(II) [14] and ruthenium(II), [13] and 1,2-di(2-thienyl)ethene iron(II) and ruthenium(II) [12] complexes. The optical absorption spectra of the complexes at concentrations of 1.0 ϫ 10 -5 m were recorded in chloroform and DMF.…”

“…The optimized structures and selected structural data can be found in the Supporting Information. The angles and bond lengths are consistent with experimental crystal data for the parent iron(II) [12] and ruthenium(II) [13] thiophene derivatives and other η 5 -monocyclopentadienylmetal complexes. [15,38,39] After the geometry optimizations, the electronic spectra were simulated by means of TD-DFT calculations.…”

“…The complexes are fairly stable towards oxidation in air and to moisture both in the solid state and in solution. The compounds were characterized by analytical data, FTIR and 1 H, 13 C and 31 P NMR spectroscopy, which supported the proposed formulations. Relevant spectroscopic data are presented in Table 1.…”

“…The magnitude of this π-back-donation is thus higher for the iron(II) compound, as expected considering the better π-donating ability of the iron(II) moiety. The benzo[c]thiophene derivatives described here show more effective π-back-donation than those possessing terthiophene units with an acceptor nitro end-group in related oligothiophene iron(II) [14] and ruthenium(II) [13] complexes. Moreover, less effective π-back-donation was found in comparison with parent 1,2-di(2-thienyl)ethene iron(II) and ruthenium(II) [12] complexes, which possess one vinylidene unit between the two thiophene rings.…”

“…Among the organometallic compounds presenting this structural feature, our group and others have carried out systematic studies on η 5 -monocyclopentadienylmetal complexes with benzene or oligothiophene conjugated chains coordinated to the metal centres through nitrile or acetylide linkages. [8,[12][13][14][15][16][17][18] In particular, very efficient NLO responses were found when strong electron donors such as iron and ruthenium organometallic moieties were coupled with strong electron acceptors like NO 2 .…”