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Two donor-acceptor copolymers containing perylene diimide and oligothiophenes linked through triple bonds have been designed and synthesized by palladium catalyzed Sonogashira coupling reaction. The introduction of the triple bond spacer between the electron-acceptor perylene moieties and the electron donating oligothiophene moieties produces an extended conjugation along the main chain, and produces soluble and high molecular weight copolymers. The thermal, optical and electrochemical properties of these copolymers were examined. The HOMO-LUMO energy levels of these copolymers, along with the photoinduced charge transfer process, probed by photoluminescence quenching and by FTIR photoinduced absorption spectroscopy, in blends with poly(3-hexylthiophene) (P3HT), indicate that they are suitable materials for application as electron acceptor and n-type components in bulk heterojunction solar cells with P3HT.

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Conducting textiles were prepared embedding polypyrrole in natural and man made cellulose-based fibres, such as cotton, viscose, cupro and lyocell, by means of in situ polymerisation. Chemical vapour phase deposition of polypyrrole is a suitable process to produce electro-conductive composites in two steps: a) fabric impregnation with an aqueous solution of oxidant and dopant and subsequent drying; b) exposition to pyrrole vapour and polymerisation. Comparative morphological and structural analysis was carried out on the conducting viscose prepared with both vapour-phase and liquid-phase processes and some significant differences in the structural, calorimetric and electrical properties were pointed out, due to the different methods of preparation. The fabrics show a high uniform polypyrrole coating on the fibre surface, with its partial penetration inside the amorphous zones of fibre bulk. WAXD analysis shows that the conducting fabrics preserve the crystalline structure of the cellulose matrix, while SAXS results evidence the presence of a nanoparticle dispersion of polypyrrole in the cellulose matrix. polypyrrole-cellulose conducting composites have a particularly wash and light-fast consistence as shown by the tests performed.

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Poly (dithienothiophene)s (PDTTs), low band-gap conjugated polymers with poly thiophene-like chain where an aromatic thienothiophene moiety is fused to each thiophene ring, were studied using Raman spectroscopy, photoinduced infrared absorption, as well as attenuated total reflection Fourier transform infrared (ATR-FTIR) and electron spin resonance (ESR) spectroelectrochemistry. The spectroelectrochemical studies were performed in situ during p- and n-doping (electrochemical oxidation and reduction, respectively). Raman lines of the pristine polymers are compared to infrared active vibration (IRAV) bands due to the charge carriers injected by the electrochemical doping processes or by illumination. The different pi-electron distribution along the polythiophene-like chain, which determines the different band-gap sizes, also account for the different lattice relaxations and vibrational behaviors shown by these polymers. By means of in situ ESR spectroscopy, the formation of paramagnetic positive and negative charge carriers with unusually high g-factors could be proved.

Poly(dithienothiophene)s (PDTTs), low band-gap conjugated polymers with polythiophene-like chain where an aromatic thienothiophene moiety is fused to each thiophene ring, were studied using Raman spectroscopy, photoinduced infrared absorption, as well as attenuated total reflection Fourier transform infrared (ATRFTIR) and electron spin resonance (ESR) spectroelectrochemistry. The spectroelectrochemical studies were performed in situ during p- and n-doping (electrochemical oxidation and reduction, respectively). Raman lines of the pristine polymers are compared to infrared active vibration (IRAV) bands due to the charge carriers injected by the electrochemical doping processes or by illumination. The different ð-electron distribution along the polythiophene-like chain, which determines the different band-gap sizes, also account for the different lattice relaxations and vibrational behaviors shown by these polymers. By means of in situ ESR spectroscopy,the formation of paramagnetic positive and negative charge carriers with unusually high g-factors could be proved

Ultraviolet absorption and Circular Dichroism spectra in the region 300- 700 nm for highly regioregular samples of Poly{3[(S)-2-methylbutyl]- thiophene} are reported for solutions in good and poor solvents, at variable temperature, and for films in various conditions. In the latter case novel CD data up to the melting temperature provide some hints for the self-assembling process towards supramolecular organization. UV- visible and CD data are also reported on the related polymer Poly{3,4-di [(S)-2-methylbutyl]-thiophene}.

Chiral polyalkylthiophenes are noncentrosymmetric organic materials which can be used both in second harmonic-generation devices and in polarized light emitting diodes. In this work we present the synthesis and the characterization of a polyalkylthiophene with a chiral center very close to the conjugated backbone: poly(3-[(S)-2-methylbutyl]thiophene) (PMBT). Circular dichroism (CD) measurements have been carried out to ascertain the chirality of these materials. The CD spectra show intense signals both in mixed solvents and in the solid state. The strong Cotton effect can be associated to a highly ordered aggregated phase whose nature is still under investigation. We also present the photo and electroluminescence characterization of single layer light emitting diode (LED) with the following configuration: ITO (Tin Indium Oxide)/PMBT/Al.

The processability and the solubility of organic materials are important in the fabricatiopn of photoelectric cinversion devices. Polydithienothiophene (PDTT)that exhibit low energy gap are promising materials pfo this application. The synthesis and the electrochemical characterization of soluble PDTT copolymers is presented By comparing electrochemical and optical data we provide information on the ionization potential and electrocic affinity of these materials.

A spectroscopical study of composites made with a new conjugated polymer, polydithienothiophene, and nanocrystalline TiO2 is carried out by optical absorption, photoluminescence and steady state photo-induced absorption spectroscopy. Sinter ed nanoporous TiO films have been stained by dipping the inorganic semiconductor films into dithienothiophene polymer solutions. The optical absorption spectra indicate that this polymer is well absorbed into nanoporous TiO films, showing a remarkable interaction with the inorganic semiconductor as compared to other alkyl substituted thiophene based conjugated polymers.Thephotoluminescence quenching and the steady state photo-induced absorption spectra evidence that TiO acts as an efficient electron acceptor toward the polymer in the excited state.These features indicate that this conjugated polymer is a promising material to develop new hybrid organicyinorganic photovoltaic cells.

Polyalkylthiophenes bearing enantiomerically pure side chains are noncentrosymmetric materials that can be used in polarized photo- and electroluminescence areas and enantioselective sensing. In this work we present the characterization of a polyalkylthiophene with a chiral center very close to the conjugated backbone: poly-3-(S)-2-methylbutylthiophene (PMBT). Differential scanning calorimetry and X-ray diffraction measurements have been performed to characterize the thermal transitions and the structural organization of this polymer. Thin films of PMBT exhibit interesting thermochromism phenomena that affect absorption, emission, and circular dichroism properties. The influences of both the film processing and the thermal treatment on the conjugated polymeric chains have been studied by UV-visible, FTIR, and Raman spectroscopies. Thermochromism has been monitored by in situ electronic absorption, circular dichroism, and photoluminescence experiments. Electroluminescence properties and the electrical characterization of a single-layer lightemitting diode are also presented. The optical and structural changes induced by the temperature are discussed in terms of the peculiar three-dimensional order found for this polymer with respect to other poly-3-alkylthiophenes.

The electrical and photoelectrical characteristics of sandwich-type devices based on regioregular head-to-tail poly(3-alkylthiophenes) have been investigated and compared with those obtained with regiorandom polymers. Better performances have been achieved in sandwich-type devices made with regioregular polymers having a short alkyl substituent. A spectroscopic and morphological investigation of the materials have been also done.

(S)-(+)-1-bromo-2-methylbutane was investigated using vibrational circular dichroism (VCD). Experimental absorption and VCD spectra of (+)-1-bromo-2- methylbutane in CDCl3 solution were recorded in the 2000-900 cm-1 region, and they were compared with the ab initio predictions of absorption and VCD spectra obtained with density functional theory using the B3LYP/6- 31G* basis set for (S)-1-bromo-2-methylbutane. This comparison indicates that (+)-1-bromo-2-methylbutane is of the (S)configuration and exists in several conformations. The results obtained for (S)-(+)-1-bromo-2- methylbutane are also compared to those for (S)-(+)-3-(2-methylbutyl) thiophene, which indicates that the predominant conformations are influenced by the substitution of bromine with thiophene ring.

Potentially bio-active 2-benzazepine, 2-benzazocine, isoquinoline derivatives were selectively synthesized from N-alkyl, N-(o-iodobenzyl)-3-butenamides and a catalytic amount of palladium complexes. The regiochemistry of the annulation leading to seven/eight- or six-membered ring formation can be completely determined varying medium polarity by the addition of water

Ultraviolet absorption and Circular Dichroism spectra in the region 300-700 nm for highly regioregular samples of Poly{3[(S)- 2-methylbutyll-thiophene] are reported for solutions in good and poor solvents, at variable temperature, and for films in various conditions. In the latterc asen ovel CD datau p to the melting temperaturep rovide some hints for the self-assemblingp rocesst owards supramolecularo rganization. UV-visible and CD data are also reported on the related polymer Poly{3 ,4-di[ (S) -2-methylbutyl]- thiophene].

Information on doping- and photoinduced phenomena and processes in materials used in organic polymeric photovoltaic systems (plastic solar cells) can be obtained using infrared spectroscopy. The methods and results for the identification of doping- and photoinduced charge carriers, investigation of charge carriers in electrochemical systems, and studies on degradation processes are shown.

Attenuated total reflection Fourier transform infrared studies of the electrochemical redox processes of poly-(dithieno[3,4-b:2¢,3¢-d]thiophene) (pDTT3), a low band gap conjugated polymer with a “polythiophene-like” backbone, where an aromatic moiety is fused to each thiophene ring, are reported. Vibrational spectroscopic studies are performed in situ during electrochemical oxidation (p-doping) and reduction (n-doping). Infrared active vibration bands due to charge carriers injected to the polymer chain are compared to photoinduced IR bands and to Raman spectra of the neutral polymer. The similar spectral features, observed during p- and n-doping processes, indicate a high charge carrier delocalization for both signs of carriers. Furthermore, the spectral evidence of the strong involvement of the fused aromatic rings to the ð-electronic structure of this low band gap polymer has been obtained.

A series of dichloro bridged arylbicycloheptylpalladium complexes have been synthesized and characterized by means of NMR spectroscopy. The compound [(C15H19)PdCl]2 with ortho and para methyl substituents at the arene has been characterized by means of X-ray diffraction techniques. The C-ipso atom of the arene lies almost at the fourth planar coordination site of the metal [Pd-Cipso = 2.22(1)Å (ave.)] and, due to the arene's tilting, the substituted Cortho atom is relatively close to the metal atom [2.54(1)Å (ave)]. The coordinated Cipso Cortho linkage, in a seemingly dihapto coordination, is anti with respect to the CH2 bridge of the bicycloheptyl unit. Variable temperature NMR experiments for the para substituted dimer 9 reveal restricted rotation of the two aryl groups about the corresponding C Cipso bonds (less then 17 kcal mol-1). DFT-B3LYP calculations have been carried out on the known and similar monomer (phenylbicycloheptenyl)Pd(PPh3)I, 4, and its related substituted derivatives. The essential results are: i) the potential energy surface for twisting the phenyl ring away from the symmetric eta1 coordination in 4 is very flat (DeltaE < 1 kcal mol-1) whereas an Atom In Molecules analysis excludes the existence of an actual Pd C-ortho bond in the seemingly eta2–type conformer. ii) complete rotation of the unsubstituted phenyl ring is not facile but feasible. A significant strain affects the transition state structure featuring a Pd-HCaryl agostic-type bond. The calculated destabilization of 10.3 kcal mol-1, with respect to the ground state, can be compared to the experimental barrier of the dimer 9. iii) various methyl substituted derivatives of 4 have been optimized and their structural and energetic trends are discussed. An almost ideal eta1 coordination is shown by the anti conformer of the Cortho substituted complex due steric effects. For all of the other cases, a slipped eta2 coordination may be described. As a general conclusion, the unsaturated metal center receives pi electron density of the arene mainly through its C-ipso atom. The effect may be slightly improved if also the Cortho atom gets closer to the metal but, in no case, the slipped eta2 coordination seems to be crucial for the stability of the system.

Conjugated polymers with narrow band gap are promising candidates for symmetric electrochemical devices, such as electrochromics and redox supercapacitors, which involve the p- and n-doped state of the polymer. Polydithienothiophene materials which are prepared from isomer monomers show this characteristic. The copolymerisation of two dithienothiophene isomers leads to materials whose electronic properties depend on the monomer ratio. Optical and electrochemical characterizations of different copolymers are reported and discussed.