José G. López-Cortés

Ferrocenylselenoamides: Synthesis, Characterization and Cytotoxic Properties

A new series of ferrocenyl selenoamides 7-11 (FcSeNH(CH(2))(n)CH(2)(R)OH, n = 1, 2, 3, R = H, Me, Ph) were prepared in good yields by selenative demetalation of Fischer aminocarbene complexes. The crystal structures of 7 [FcSeNH(CH(2))(2)OH] and 19 [PhSeNH(CH(2))(2)OH] reveal their capability to form intermolecular hydrogen bonding in solid state. Results of SRB assays show that these new selenium compounds have a good anticancer potency superior to tamoxifen and cisplatin, with IC(50) values ranging from 4.5 to 13.32 μM against human breast cancer cell lines. A preliminary model to explain the structure-cytotoxic activity relation is proposed where different structural parameters such as the alkyl chain length, the presence of bulky groups in the same chain, the effect of hydroxyl group, and also the role of ferrocene moiety are included as being responsible for the cytotoxic response.

Infrared irradiation assisted both the synthesis of (Z)-(aminomethyl)(aryl)phenylhydrazones via the Mannich coupling reaction and their application to the palladium-catalyzed Heck reaction

The Mannich coupling reaction between arylhydrazones, formaldehyde and a secondary amine to generate the ( Z)-(aminomethyl)(aryl)phenylhydrazones 1a–h assisted by infrared irradiation (IR) under solvent-free conditions is herein reported, and the catalytic potential of compounds 1a–h in the palladium-catalyzed and IR-assisted Heck coupling reaction is also evaluated. Coupling products are obtained in high yields and short reaction times. We show the advantages of this new alternative to promote both Mannich and Heck coupling reactions.

Ferrocene amphiphilic D–π–A dyes: synthesis, redox behavior and determination of band gaps

We report the synthesis of a series of ferrocene amphiphilic donor–π–acceptor dyes, with the general formula (Fc-CHCH-HetNC16H33)+ X− [where: Fc behaves as the donor group, a double bond as the π bridge, and 2-,4-pyridinium and 4-quinolinium as the potent acceptor groups (2a–b and 4, X = Br− or BF4−)], in good overall yields. Together with their neutral counterparts (6a–b and 7), the photophysical and electrochemical properties of these compounds were investigated by means of UV-Vis spectroscopy and cyclic voltammetry. The optical and electrochemical band gaps of these dyes were calculated, which indicated that 4 has the lowest bandgap value. Time-dependent DFT calculations indicate that the lowest energy absorption band displayed for these compounds has mainly metal-to-ligand charge transfer character, with the HOMO–LUMO electronic transition being the main contribution.

Nanostructured Thin Films Obtained from Fischer Aminocarbene Complexes

The synthesis of four amphiphilic organometallic complexes with the general formula RC = M(CO)5NH(CH2)15CH3, where R is a ferrocenyl 2(a-b) or a phenyl 4(a-b) group as a donor moiety and a Fischer carbene of chromium (0) or tungsten (0) as an acceptor group, are reported. These four push-pull systems formed Langmuir (L) monolayers at the air-water interface, which were characterized by isotherms of surface pressure versus molecular area and compression/expansion cycles (hysteresis curves); Brewster angle microscopic images were also obtained. By using the Langmuir–Blodgett (LB) method, molecular monolayers were transferred onto glass substrates forming Z-type multilayers. LB films were characterized through ultraviolet-visible spectroscopy, atomic force microscopy and X-ray diffraction techniques. Results indicated that films obtained from 2b complex [(Ferrocenyl)(hexadecylamine)methylidene] pentacarbonyl tungsten (0) are the most stable and homogeneous; due to their properties, these materials may be incorporated into organic electronic devices.

Electronic Effects on the Reactivity of Cross-Conjugated Carbonyl Systems with Fe 2 (CO) 9

Neste trabalho foram estudados os efeitos eletronicos induzidos por p-substituintes no anel fenilico de diversos compostos carbonilicos conjugados [4-p-R-fenil-1-(1,3-ditiolano-2-ilideno)3E-buteno-2-ona, onde R=NO 2 , Cl, Br, OMe, NEt 2 (2-6)], e sua reatividade frente a Fe 2 (CO) 9 usando o diagrama de Hammett. A estrutura dos compostos (3 e 4b) foi totalmente estabelecida por analise de difracao de raio-X. The electronic effects induced by p-substituents on the phenyl ring of several novel crossconjugated carbonyl compounds [4-p-R-phenyl-1-(1,3-dithiolane-2-ylidene)-3E-butene-2-one, where R= NO 2 , Cl, Br, OMe, NEt 2 (2-6),] and their reactivity towards Fe 2 (CO) 9 have been studied using a Hammett plot. The structure of two compounds (3 and 4b) was fully established by X-ray diffraction analysis.