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This article describes the synthesis, characterization and DNA-binding assays of a series of oxadiazoles derived from ( E )-3-ferrocenylacrylic acid. The compounds were obtained in satisfactory yields and characterized by NMR and high resolution mass spectrometry analysis. Additionally, the X-Ray characterization of compound 8a was investigated. A series of ferrocenylethenyl-substituted 1,3,4-oxadiazolyl-1,2,4-oxadiazoles was prepared and studied by UV-visible and electrochemical techniques. The characteristic signals of the redox-active ferrocene/ferrocenium couple were monitored, which allowed verification of the influence of electron-withdrawing oxadiazole heterocycles and their dependence on the 1,2,4-oxadiazole substituent. Also, DNA-binding experiments were performed by UV-vis and emission titrations with ct-DNA. [ABSTRACT FROM AUTHOR]

Host–guest interactions between ferrocene (Fc) and its derivatives containing electron donating and electron withdrawing substituents viz., 2-ferrocenyl benzoxazole (FcOz) or 2-ferrocenyl benzothiazole (FcTz) and cucurbit [7]uril (CB[7]) host have been analyzed employing density functional theory incorporating various exchange correlation functionals. Electronic structures of these complexes reveal the encapsulation of ferrocene ring within the CB[7] container with the benzoxazole or benzothiazole substituent interacting with host portals via C = O ⋯ H interactions. Further the M06-2X based calculations show stronger host–guest binding compared to those predicted from wB97x, PBE0 and B3LYP functionals. The contributions of electrostatic and other dispersive interactions toward such binding have been assessed. The 1 H NMR chemical shifts from the gauge independent atomic orbital (GIAO) theory using different functionals demonstrated that subtle changes in δ H signals of cyclopentadienyl protons and those encapsulated in the CB[7] cavity in water are better reproduced by the wB97x functional. Calculated infrared spectra revealed that the complexation is accompanied by frequency shift of the C–N stretching in benzoxazole or benzothiazole ring, and the characteristic methine and carbonyl vibrations of CB[7]. The direction of such frequency shifts has been explained from the natural bond orbital analyses and ‘Quantum Theory of Atoms in Molecules’ approach. Time dependent density functional theory calculations further demonstrated that substitution on the cyclopentadienyl ring brings a bathochromic shift of the ~ 200 nm band in the electronic spectra for the unsubstituted Fc-CB[7] complex. Furthermore, FcOz@CB[7] or FcTz@CB[7] complexes exhibit low energy absorption band at ~ 480 nm in its electronic spectra as a result of intramolecular charge transfer from 3d orbitals of Fe to π* orbitals of benzothiazole or benzoxazole, unlike that in the Fc@CB[7] complex. [ABSTRACT FROM AUTHOR]

A series of structurally novel organometallic compounds ( 3a – g ) based on 1-biaryl-3-ferrocenylprop-2-en-1-one, were synthesized by the Suzuki-Miyaura cross-coupling reaction for applications as nonlinear optical (NLO) and liquid crystal (LC) materials. Notably, a single crystal of this class of compounds was obtained for the very first time, and it was found that the two phenyl rings of the chalconyl group were nearly coplanar to one of the cyclopentadienyl rings of ferrocene. Due to the high degree of conjugation, all the chalcone analogues of ferrocenyl biaryl derivatives displayed strong second harmonic generation (SHG) response (0.45–0.60 × 10 −30 esu, 3–4 times greater that of potassium dideuterophosphate (KDP)). The density functional theory (DFT) was employed to calculate the main molecular orbital energies and compositions of 3d , based on its crystallographic structure. Compound 3d was found to exhibit excellent NLO properties due to its low E gap and superior charge transfer ability within the conjugated system. This work presents a new approach for the preparation of this class of ferrocenyl biaryl derivatives, which may have potential applications as NLO materials. [ABSTRACT FROM AUTHOR]

Abstract: Novel slender hydrophobic ferrocenyl molecules (1–9) synthesized by efficient one-pot method in global high yields having poor aqueous solubility are driving molecules in formation of inclusion complexes with β-CD to self-assemble into vesicles in water. These vesicles were observed by TEM and confirmed by DLS, SEM and AFM for the first time. According to the complex stoichiometry and stability constant by UV, the one-head and one-tail “tadpole-like supramolecular amphiphiles” based on these inclusion complexes between driving molecules and β-CD were firstly assumed to construct these vesicles. Effects of chain length in driving molecules on formation of vesicles were estimated for the first time. The response of these vesicles to an oxidizing agent was also discussed. This work promotes to establish complete theoretical system of “supramolecular amphiphiles” and paves the way to combine supramolecular host–guest chemistry and membrane chemistry for potentially functional applications such as biomaterials for the separation of bacteria. [Copyright &y& Elsevier]

New ferrocenyl derivatives (a β-ketoester and a β-diester) were synthesised and linked to fullerene C60, with the aim to elucidate factors involved in intramolecular electronic communication. These are the first examples of fullerene functionalised with ferrocenes via the cyclopropanation reaction. The resulting dyads were characterised. [Copyright &y& Elsevier]

Excited-state study of amino-ferrocenyl porphyrin derivatives • Excited state and intersystem crossing mechanism for amino-ferrocenyl porphyrins were investigated. • NLO properties of amino-ferrocenyl substituted porphyrins were investigated. • Z-Scan technique was explored in the amino-ferrocenyl porphyrins derivatives. • Aliphatic chain spacers size not affected the associated electronic transitions and properties. The spectroscopic study and characterization of mono-(amino-ferrocenyl) porphyrins has increased during the last years. These molecules can be synthesized in such a way that their linear and nonlinear optical parameters are modulated, opening the possibility for new applications, such as in photodynamic therapy. In this work, we perform a spectroscopic characterization of a group of five free-base porphyrins, three of them having a C 6 F 4 group attached to an amino-ferrocene moiety through a −NH(CH 2) n NH− spacer, in which n = 2, 4 or 6. These three molecules differ by the size of the aliphatic chain. For this study, we employ linear as well as nonlinear optical spectroscopic techniques, such as the Z-Scan and time resolved fluorescence. Decay times, absorption cross-sections and quantum yields were determined, and the results suggest that, for this group of molecules, the differences in the aliphatic chain sizes joining the ferrocenyl unit to the C 6 F 4 group at the para -position aryl ring do not influence significantly the optical parameters. Further, DFT calculations confirm that the UV–vis absorbance and the associated electronic transitions are not affected by the size of the aliphatic chain spacers. Thus, it is possible to state that these molecules can interact with biomolecules through the ferrocene unit while keeping their optical properties unchanged. [ABSTRACT FROM AUTHOR]