Nanotube composites consisting of metal nanoparticles and polythiophene from electropolymerization of terthiophene-functionalized metal (Au, Pd) nanoparticles

Thiophene-Based Trimers and Their Bioapplications: An Overview

Certainly, the success of polythiophenes is due in the first place to their outstanding electronic properties and superior processability. Nevertheless, there are additional reasons that contribute to arouse the scientific interest around these materials. Among these, the large variety of chemical modifications that is possible to perform on the thiophene ring is a precious aspect. In particular, a turning point was marked by the diffusion of synthetic strategies for the preparation of terthiophenes: the vast richness of approaches today available for the easy customization of these structures allows the finetuning of their chemical, physical, and optical properties. Therefore, terthiophene derivatives have become an extremely versatile class of compounds both for direct application or for the preparation of electronic functional polymers. Moreover, their biocompatibility and ease of functionalization make them appealing for biology and medical research, as it testifies to the blossoming of studies in these fields in which they are involved. It is thus with the willingness to guide the reader through all the possibilities offered by these structures that this review elucidates the synthetic methods and describes the full chemical variety of terthiophenes and their derivatives. In the final part, an in-depth presentation of their numerous bioapplications intends to provide a complete picture of the state of the art.

Synthesis of nanoparticle/ligand composite thin films by sequential ligand self assembly and surface complex reduction

Nanocomposite thin films consisting of ligand-connected metal nanoparticles were deposited by iteration of ligand assembly, surface complex formation and reduction. This novel and convenient approach combines characteristics of the layer-by-layer (LbL) and the successive ion layer adsorption and reaction (SILAR) techniques. In contrast to classical LbL assembly, the nanoparticle formation is performed in situ, avoiding separate reduction, protection and attachment steps. To demonstrate the versatility of the approach, different metal precursors (Pd, Ag and Au salts) and linkers (1,2-ethanedithiol, 1,4-benzenedithiol and polythiol) were applied. The formation of dithiol-linked nanoparticle films was confirmed by TEM and XPS. By combining the deposition protocol with ion track etched polycarbonate templates, nanotubes and nanowires with high aspect ratios of up to 300 could be fabricated.

Hybridization of inorganic nanoparticles and polymers to create regular and reversible self-assembly architectures

Inorganic nanoparticles (NPs) with diversified functionalities are promising candidates in future optoelectronic and biomedical applications, which greatly depend on the capability to arrange NPs into higher-order architectures in a controllable way. This issue is considered to be solved by means of self-assembly. NPs can participate in self-assembly in different manners, such as smart self-organization with blended molecules, as the carriers of host molecules for assembly and disassembly with guest molecules, as netpoints to endow the architectures specific functionalities, and so forth. To enhance the structural stability of the as-prepared assembly architectures, polymers have been utilized to create NP-polymer composites. Meanwhile, such a strategy also demonstrates the possibility of integrating the functionalities of NPs and/or polymers by forming regular architectures. The emerging interest in the current optoelectronic and biological areas strongly demands intelligent nanocomposites, which are produced by combination of the excellent functionalities of NPs and the responsiveness of polymers. On the basis of the recent progress in fabricating NP-polymer composites, this critical review summarizes the development of new methods for fabricating regular self-assembly architectures, highlights the reversible assembly and disassembly behavior, and indicates the potential applications.

Synthesis of chiral hybrid nanotubes of magnetite nanoparticles and conducting polymers

New chiral magnetite nanoparticles with a polymerizable group produced polymer composite films on an electrode surface and the hybrid nanotubes of magnetite nanoparticles and polythiophene from their template-based electropolymerization.

Synthesis of heterosegment-junctioned hybrid nanotubes of polythiophene and heterometallic nanoparticles by sequential template-based electropolymerization

New heterosegment-junctioned hybrid nanotubes of polythiophene and heterometallic nanoparticles (Pd, Au NPs) have been synthesized by sequential electropolymerization of terthiophene-modified Pd and Au NPs in a nanoporous template.

Electronic structures of bis- and monothiophene complexes with Fe, Co, Ni: a density functional theory study

A density functional theory study for the bis- and monothiophene complexes of Fe, Co, and Ni (MT2 and MT, T = thiophene, M = Fe, Co, Ni) was performed to understand their coordination geometries, bonding properties, vibration spectra and singlet excited state spectra. The typical metal coordination exists in the complexes. The Fe-thiophene coordination has the highest stability, with Ni-thiophene being the second highest, and Co-thiophene the lowest. Bisthiophene complexes of Co and Ni prefer to homolytically dissociate to their monothiophene ones and free thiophene. Frequency calculation shows that the ligand-M-ligand asymmetric stretching vibration in bisthiophene complexes shows a strong absorption, at 435.2, 495.7, and 383 cm(-1) for Fe(eta4-T)2, Co(eta2-T)2 and Ni(eta2-T)2, respectively. The M-S stretching vibration in monothiophene complexes shows a strong absorption in the far-infrared region, at 209, 156, and 150 cm(-1) for Fe(eta4-T), Co(eta4-T) and Ni(eta5-T), respectively. The excited state spectra indicate that the characteristic absorption wavelengths of the complexes have a red shift of more than 12.40 eV compared to free thiophene, at 3.54, 1.64, 3.83, 2.75, 1.43, and 2.58 eV for Fe(eta4-T)2, Co(eta2-T)2, Ni(eta2-T)2, Fe(eta4-T), Co(eta4-T), and Ni(eta5-T), respectively.

Metallization of a thiol-terminated organic surface using chemical vapor deposition

The deposition and the subsequent decomposition of an organometallic precursor, (eta (3)-allyl)(eta (5)-cyclopentadienyl)palladium [Cp(allyl)Pd], on an organic surface exposed by self-assembled monolayers (SAM) was studied using X-ray photoelectron spectroscopy (XPS) and infrared reflection absorption spectroscopy (IRRAS). The interfacial chemical reactions of the vapor-deposited metal precursor with the pendant thiol group of the SAMs made from oligophenyldithiols, which are either prepared directly (terphenyldimethyldithiol, TPDMT) or by a deprotection route from SAMs formed by a monoacylated derivative of biphenyldimethyldithiol (dep. BPDMAc-1) have been studied in detail. When the TPDMT-SAMs were exposed to Cp(allyl)Pd vapor, a Pd (2+)/allyl-terminated SAM surface was obtained (to a lower extent this was also the case for dep. BPDMAc-1 SAMs), which was stable against exposure to H 2 gas. Reduction to Pd (0) by H 2 was only observed when small amounts of Pd (0) were already present, for example, after prolonged exposure to the precursor. The catalytic activity of the small Pd (0) particles also caused a decomposition of the SAMs upon exposure to air.