In this article we highlight, by means of selected examples drawn from work performed in our or other laboratories, the features of some classes of fluorinated conjugated materials and their use in electronic devices such as electroluminescent diodes or field effect transistors. A variety of fluorinated conjugated systems, either molecular or polymeric, such as poly(phenylenevinylene)s, poly(phenyleneethynylene)s, polythiophenes, polyphenylenes, are dealt with. Attention is also focused on a different class of electroluminescent compounds, represented by the cyclometalated iridium complexes with various forms (mer and fac). In particular, fluorine atoms lower both the HOMO and LUMO energy levels. Consequently, the electron injection is made easier, the materials display a greater resistance against the degradative oxidation processes and organic n-type or ambipolar semiconducting materials may result. Moreover, the C-H...F interactions play an important role in the solid state supramolecular organization, originating a typical pi-stack arrangement which enhances the charge carrier mobility.

Organic thin-film transistor sensors have been recently attracting the attention of the plastic electronics community for their potential exploitation in novel sensing platforms. Specificity and sensitivity are however still open issues: in this respect chiral discrimination-being a scientific and technological achievement in itself--is indeed one of the most challenging sensor bench-tests. So far, conducting-polymer solid-state chiral detection has been carried out at part-per-thousand concentration levels. Here, a novel chiral bilayer organic thin-film transistor gas sensor--comprising an outermost layer with built-in enantioselective properties-is demonstrated to show field-effect amplified sensitivity that enables differential detection of optical isomers in the tens-of-parts-per-million concentration range. The ad-hoc-designed organic semiconductor endowed with chiral side groups, the bilayer structure and the thin-film transistor transducer provide a significant step forward in the development of a high-performance and versatile sensing platform compatible with flexible organic electronic technologies.

Homoleptic Ir(Fnppy)3 and heteroleptic (Fnppy)2Ir(acac) complexes (n = 3: F3ppy =\ud 2-(39,49,69-trifluorophenyl)pyridine; n = 4: F4ppy = 2-(39,49,59,69-tetrafluorophenyl)pyridine;\ud acac = acetylacetonate) have been synthesized and their spectroscopic properties investigated. The\ud homoleptic complexes exist as two stereoisomers, facial (fac) and meridional (mer), that have been\ud isolated and fully characterized. Their electrochemical and photophysical properties have been\ud studied both in solution and in the solid state and electroluminescent devices have been fabricated.\ud The emissive layers in devices have been obtained mixing the iridium complexes with a PVK\ud [poly(9-vinylcarbazole)] host matrix, in the presence of the electron carrier Bu-PBD [2-(4-\ud biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole]. The application of a voltage (5.0–6.5 V)\ud between the electrodes of devices leads to electro-generated blue luminescence which has similar\ud energy to the solution emissions. Interestingly, the stability of the devices made with the\ud homoleptic fluorinated iridium complexes strongly depends on the stereochemistry of these\ud phosphors and high (up to 5.5%) external quantum efficiencies for the fac complexes are\ud measured

Results of special interest in the field of organometallic\ud chemistry directed towards the synthesis of conjugated\ud oligomers and polymers are reviewed. Methodologies\ud widely employed in the synthesis of well-defined molecules\ud and based on the transition metal catalyzed coupling\ud reactions of various organometallic (B, Sn, Si, Mg and Zn)\ud reagents have been more recently extended to build up polyor\ud oligo-meric conjugated molecular architectures.\ud Although the focus of the present work is on transition\ud metal cross-coupling or homo-coupling processes, other\ud useful organometallic routes, such as metathesis reactions\ud and acetylene polymerization, have also been dealt with.\ud Owing to their higher versatility with respect to the nonorganometallic\ud processes commonly used for the synthesis\ud of these materials, the approaches presented allow the\ud realization of more complex molecular structures, which are\ud nowadays required in many electronic and optoelectronic\ud applications. The use of organometallic strategies has been\ud discussed from a synthetic organic chemist’s point of view,\ud and advantages and limitations of the different\ud methodologies reviewed have been highlighted. Some\ud attention has also been paid to the properties of the resulting\ud materials and to their dependence on the procedure\ud followed and the framework obtained

Bequeme Routine: Mehrlagige dünne Polymerfilme wurden durch Elektrophorese auf in Agarose immobilisierten Partikeln angeordnet. Anschließendes Entfernen des Kerns führte zu robusten Kapseln mit unterschiedlichen Polymerzusammensetzungen (siehe Fluoreszenzbild). Dieser Ansatz ermöglicht den vielseitigen und routinemäßigen Aufbau von nano‐ und mikroskaligen Kapseln sowie beschichteten Partikeln in sehr wenigen Prozessschritten.

Self-assembled monolayers (SAMs) derived of 4-methoxy-terphenyl-3'',5''-dimethanethiol (TPDMT) and 4-methoxyterphenyl-4''-methanethiol (TPMT) have been prepared by chemisorption from solution onto gold thin films and nanoparticles. The SAMs have been characterized by spectroscopic ellipsometry, Raman spectroscopy and atomic force microscopy to determine their optical properties, namely the refractive index and extinction coefficient, in an extended spectral range of 0.75-6.5 eV. From the analysis of the optical data, information on SAMs structural organization has been inferred. Comparison of SAMs generated from the above aromatic thiols to well-known SAMs generated from the alkanethiol dodecanethiol revealed that the former aromatic SAMs are densely packed and highly vertically oriented, with a slightly higher packing density and a absence of molecular inclination in TPMT/Au. The thermal behavior of SAMs has also been monitored using ellipsometry in the temperature range 25-500 degrees C. Gold nanoparticles functionalized by the same aromatic thiols have also been discussed for surface enhanced Raman spectroscopy applications. This study represents a step forward tailoring the optical and thermal behavior of surfaces as well as nanoparticles.

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2,5-Dialkoxypoly(p-phenyleneethynylene) (3) functionalized with N-t-BOC-L-phenylalanine molecules was synthesized by Pd-catalyzed reaction of dioctyloxybis[(trimethylsilyl) ethynyl] benzene (1) with aromatic diiodide 2 linked to two amino acid units by six carbon atoms alkoxy chains. Optical properties were investigated both in solution and in the solid state (as thin films) by absorption, fluorescence and chiroptical spectroscopies (CD and CPL). Polymer 3, that represents one of few fully characterized dialkoxy-substituted PAEs, is also the first example of a poly(aryleneethynylene) (PAE) with amino acidic chiral pendants