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Novel coordination polymers embedding electroactive moieties present a high interest in the development of porous conducting materials. While tetrathiafulvalene (TTF) based metal-organic frameworks were reported to yield through-space conducting frameworks, the use of S-enriched scaffolds remains elusive in this field. Herein is reported the employment of bis(vinylenedithio)-tetrathiafulvalene (BVDT-TTF) functionalized with pyridine coordinating moieties in coordination polymers. Its combination with various transition metals yielded four isostructural networks, whose conductivity increased upon chemical oxidation with iodine. The oxidation was confirmed in a single-crystal to single-crystal X-ray diffraction experiment for the Cd(II) coordination polymer. Raman spectroscopy measurements and DFT calculations confirmed the oxidation state of the bulk materials, and band structure calculations assessed the ground state as an electronically localized antiferromagnetic state, while the conduction occurs in a 2D manner. These results are shedding light to comprehend how to improve through-space conductivity thanks to sulfur enriched ligands., This work was supported in France by the CNRS and the University of Angers (PhD funding to F.S.). N.A. and I.O. thank the Narodowa Agencja Wymiany Akademickiej – NAWA (Poland, BPN/BFR/2021/1/00001/U/00001) and the French Ministry of Foreign Affairs and the French Ministry of Education and Research (France, PHC Project 48119PG) for financial support through the bilateral Polonium project. The work in Poland was supported within the Statutory Activities of the Institute of Molecular Physics Polish Academy of Sciences and partially supported at Poznan University of Technology by the Research Project of the Polish Ministry of Education and Science 0511/SBAD/2251. Work in Spain was supported by MICIU through Grants PGC2018-096955-B-C44 and PGC2018-093863-B-C22, and Generalitat de Catalunya (2017SGR1506 and 2017SGR1289). E.C. acknowledges support of the Spanish MICIU through the Severo Ochoa FUNFUTURE (CEX2019-000917-S) Excellence Centre distinction and P. A. from the Maria de Maeztu Units of Excellence Program (MDM-2017-0767)., With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).

We report structural, transport, and optical properties and electronic structure calculations of the δ'-(BEDT-TTF)

In this paper results of a study of mechanical, optical and electrical properties of thin films made of multiwall carbon nanotubes (MWCNT) of various types were reported. The MWCNT films were obtained on quartz substrates using the Langmuir-Schaefer (LS) method. A gradual increase in transmittance was recorded with decreasing diameters of MWCNT used. Moreover, a blue shift of the π-plasmon band position was observed with increasing MWCNT diameter. In all tested films, anisotropy of electrical surface resistivity was revealed, which was more pronounced for MWCNT of low diameters, except for the MWCNT sample of the smallest diameters. Results of oscillatory barrier measurements of various MWCNT films at the air water interface were used to calculate the complex compression and shear moduli. It is worth emphasizing that the values of these moduli were obtained for the first time for carbon nanotubes films. Moreover, the obtained results allowed identification of the main factor blocking the alignment process, which turned out to be the shear loss tangent.

The Langmuir and Langmuir-Blodgett techniques have been widely used for nearly a century for the production of molecular thin layers with controlled packing and intermolecular distances. Unfortunately, the Langmuir layers of non-amphiphilic molecules have unstable and unrepeatable parameters. The addition of chemical compounds such as liquid crystals can stabilize and prevent aggregation in the Langmuir layer. The aim of the study was to obtain and characterize Langmuir and Langmuir-Blodgett layers of selected dithiophene diketopyrrolopyrrole (DPP) derivatives and to improve their parameters by forming mixtures with 4‑octyl‑4′‑cyanobiphenyl (8CB). Two DPPs with alkyl chains symmetrically and asymmetrically attached to pyrrole unit were chosen for the investigation. The Langmuir layer of the asymmetrical DPP was unstable over time. For the symmetrically functionalized DPP, after transferring onto solid substrates, agglomerates formation was clearly seen. For DPPs/8CB mixtures, a significant improvement in stability over time was achieved. The confocal microscopy investigation revealed almost complete removal of agglomerate structures in the symmetrical DPP with 8CB. The results proved the miscibility of components at air/water interface and the stabilizing effect of 8CB on DPPs layers. Furthermore, the addition of 8CB forces DPP J-type aggregation in the Langmuir film. Above all, the stable layers with repeatable parameters, made of indistinctly amphiphilic DPP dyes, were shown to form at the air/water interface and on solid substrates.

The (N-Xy-Qn)(TCNQ)

Two diketopyrrolopyrrole derivatives (DPPs) with spatial substituents (di-tert-butylbenzyl groups) and alkyl chains have been synthesized and investigated using DFT and TD-DFT calculations, vibrational (IR and Raman), electronic (absorption, fluorescence) spectroscopies, and electrochemical methods. Moreover, the creation of Langmuir layers was also investigated. The most of spectral investigations show only small differences between the investigated species as well as the electrochemical data. The electronic spectra show a small shift of the Soret and Q bands while the vibrational spectra in comparison with DFT calculation results suggest the presence of additional interactions involving the thiophene rings in one of the samples. The significant difference is observed in the formation of Langmuir layers of the mentioned molecules. The DPPs with spatial substituents form more densely packed layer in comparison with alkyl chain-substituted DPPs. Moreover, substitution with di-tert-butylbenzyl groups enhances the fluorescence quantum yields (up to 0.77) and slightly prolonging the fluorescence lifetimes (to over 5 ns). Spectroscopic studies of varied polarity solutions indicates J type aggregation of DPPs.

The Multiwalled carbon nanotube (MWCNT) thin films has been formed on PVC substrate using Langmuir-Blodgett technique as highly promising material for optoelectronics. The layers were annealed at 367 K which has led to significant electrical resistance decrease. The resistance of the obtained layer was investigated in wide temperature range showing the dependence significantly different from that observed for the layers created using CNTs of smaller diameter. The reason of the unusual conductivity temperature dependence is most probably the difference in thermal expansion coefficients of MWCNTs and the polymer combined with relatively high stiffness of the nanotubes with such large diameter.

To determine the energy gaps of four commercially available phthalocyanines spectroscopic and electrochemical studies were carried out. A studied dyes were investigated in solutions, 2D Langmuir layers in water–air interface and form of thin films deposited onto solid substrates. Experimental studies were complemented by DFT calculations performed for isolated molecule and molecule interacting with solvents. Conducted studies allowed to deduce the influence of molecular structure on energy gaps of phthalocyanine. Great compatibility of experimental results and DFT calculations was observed. It was found that the MP2 method results with values of molecular orbitals energies strongly differing from DFT results. The MP2 method results were divergent with experimental results.

The diketopyrrolopyrrole derivatives with long alkyl chains were synthesised and spectrally characterised. Experimental spectroscopic techniques were supplemented by the DFT calculations of equilibrium geometries, normal mode frequencies and time-dependent DFT simulated UV–vis spectra. Comparison between the symmetrical and unsymmetrical substitution of alkyl chains resulted in some changes like bathochromic shift of absorption, excitation and emission spectra, significant reduction of molar absorption coefficient in UV–vis range, increase of fluorescence quantum yield, and slight increase of fluorescence lifetimes. The influence of the length of the alkyl chain on the properties of material was also discussed. The experimental spectroscopic data together with the calculated results show that presence of the alkyl substituent at the nitrogen atom influences more on the properties of the investigated DPPs than the length of attached chain.

Thin films of randomly dispersed carbon nanotubes make highly promising material for transparent electrode applications. Knowing and understanding the nature of the films conductivity is crucial for improvement of their electrical properties. In the paper we present our investigation of electrical conductivity of single wall and multiwalled carbon nanotube (SWCNT and MWCNT) thin films deposited on a polymeric substrate by Langmuir-Schaefer technique. The conductivity of the films is consistent with the Variable Range Hopping (VRH) model. Moreover, remarkable differences in SWCNT and MWCNT films conductivity are observed. A significant impact of the thin film annealing and its temperature history on the conductivity properties is shown. The study of the carbon nanotubes layers transferred on polymeric substrate was undertaken in view of the films possible applications in flexible transparent electrodes. The VRH conductivity in carbon nanotube Langmuir-Schaefer layer is reported for the first time.

We present single-crystal x-ray diffraction measurements, optical investigations, and electronic structure calculations for the organic charge-transfer salt ${\ensuremath{\beta}}^{\ensuremath{'}}$-(BEDT-TTF)${}_{2}{\mathrm{CF}}_{3}{\mathrm{CF}}_{2}{\mathrm{SO}}_{3}$ synthesized by electrocrystallization. Electronic structure calculations confirm the quasi-one-dimensional behavior of the compound and optical conductivity measurements reveal the dimer-Mott insulating nature of the system. The splitting of the charge-sensitive ${\ensuremath{\nu}}_{2}$ mode in Raman spectra demonstrates the onset of an interlayer charge-ordered phase below 25 K, also suggested by the crystal structure considerations. This transition is accompanied by clear signatures of a lattice distortion in the BEDT-TTF donor layer, as shown by a splitting of the vibrational ${\ensuremath{\nu}}_{3}$ mode in infrared spectra. At the same time, the sharp redshift of the ${\ensuremath{\nu}}_{1}$ mode involving the BEDT-TTF ethylene groups strongly suggests a significant modification of the hydrogen-type bonding present between the BEDT-TTF donor layer and the ${\mathrm{CF}}_{3}{\mathrm{CF}}_{2}{\mathrm{SO}}_{3}^{\ensuremath{-}}$ anion layer. These observations point to a subtle interplay of charge and lattice degrees of freedom at the phase transition.

International audience; Electrocrystallization of TMTTF (tetramethyltetrathiafulvalene) in the presence of the dianionic [Pt(qS)(2)](2-)platinum complex (qS: 5-sulfo-8-quinolinol) afforded simultaneously two phases. Phase A with isolated dicationic (TMTTF)(2)(2+)species is fully insulating and characterized by C-H hydrogen bonds with the anionic sulfonate moieties. Phase B is a mixed valence salt formulated as (TMTTF)(3)[Pt(qS)(2)]. It is organized into strongly trimerized chains, with a notably higher conductivity (sigma(RT)= 4 x 10(-5)S cm(-1)). The charge distribution within the TMTTF trimers has been evaluated from the intramolecular bond distances, and IR and Raman spectra, converging all to a +0.5/+1/+0.5 motif, which is not modified at lower temperatures. Spectroscopic studies of such trimeric structures are scarce and the doublet (or triplet) structure expected in the IR of trimers is clearly identified here in the EMV-activated nu(8)(a(g)) mode associated with the totally symmetric vibration of methyl groups, in relation to the weak C-HMIDLINE HORIZONTAL ELLIPSISO hydrogen bonds between the radical cation and the dianionic [Pt(qS)(2)](2-)platinum complex.

International audience; Combination of DFT calculations and solid-state temperature-dependent infrared spectroscopy has confirmed that the central core of recently developed bipyrimidine-based mesogens is not flat, i.e. do not adopt a disc shape, inside the columnar liquid-crystalline phase. For this purpose, the intensities and the frequency shifts of the most sensitive C–N and C–C bands of the central bipyrimidine core have been studied as a function of the temperature and of the dihedral angle. The results support the reported packing model in which the molecules are interdigitated alternatively along their long axis and their short axis to form columns inside the mesophase.

Anti-Stokes luminescence of up-converting nanocrystals SrF2:Yb3+,Er3+ can be used as a high pressure optical sensor alternative to the ruby fluorescence-scale. In nanocrystalline SrF2:Yb3+,Er3+, high pressure reversibly shortens the emission lifetimes nearly linearly up to 5.29 GPa at least. Its advantage is the use of NIR (≈980 nm) radiation, highly penetrable for many materials. The shortening of up-conversion lifetimes has been attributed mainly to the changes in energy transfer rates, caused by decreased interatomic distances and increased overlap integrals between 4f electrons and the valence shells of ligand ions. The origin of high-pressure effects on the luminescence intensity, band ratio and their spectral position has been explained by the increased interactions and distortions of the crystal-field symmetry around the emitting ions in the compressed structure.

This paper examines photophysical properties of an unsymmetrical zinc phthalocyanine substituted with a terminal alkynyl group. The studies were concentrated on absorption (in the UV–vis–IR range) and fluorescence (steady-state and time resolved) in chloroform of unsymmetrical 9(10), 16(17), 23(24)-tri-tert-butyl-2-(pent-4-yloxy)phthalocyaninato zinc(II) of different concentrations. Moreover, dye photodegradation studies were also done. Besides, a laser-induced optoacoustic spectroscopy was also used to determine thermal deactivation as well as singlet oxygen generation yield. The Langmuir layers of the dye were formed and the in-situ absorption technique was applied to follow ability of the dye to aggregate formation. The experimental data were supported by the quantum chemical calculations with the use of the time-dependent density functional theory (TD-DFT) to obtain information on the distribution of electron density and electronic transitions in the molecular systems. The spectroscopic results of the unsymmetrical zinc phthalocyanine were confronted with the data of the symmetric zinc phthalocyanine.

Single polymer composites are special type of composite made solely of one polymer. They are characterized by promising mechanical properties but the manufacturing process is very difficult to scale to mass production. In this paper a method of testing polymer fibers and single polymer composites was developed. The method provides fast and nondestructive detection of structural defects in fibers and delamination in single polymer composites, therefore it can be applied to quality control of the fibers as well as composites. The method based on the laser scanning confocal microscopy, that uses laser to scan the surface of the specimen and detect light of wavelength longer than laser beam. The results show that the luminescence occur only in the defected or delaminated spots of the sample. Raman and IR spectroscopies were used to analyze the source of the luminescence. The study indicates that the influence of impurities, additives and effects of chemical degradation of polymer doesn’t lead to luminescence of the specimen. As the explanation of the effect mechanical stress assisted photoluminescence was proposed.

The crystal structure of a binuclear mono­carboxyl­ato dirhenium(III) complex with a fulvalene derivative is reported. This compound represents a radical cation salt containing a cluster unit with rhenium–rhenium quadruple bond., The asymmetric unit of the title salt, (C10H8S8)[Re2Br6(CH3COO)]·0.5C2H3Cl3, contains one bis­(ethyl­enedi­thio)­tetra­thia­fulvalene (ET) radical cation, one μ2-acetato-bis­[tri­bromido­rhenate(III)] anion and a 1,1,2-tri­chloro­ethane mol­ecule with half-occupancy disordered about a twofold rotation axis. The tetra­thia­fulvalene fragment adopts an almost planar configuration typical of the ET radical cation. The C atoms of both ethyl­enedi­thio fragments in the cation are disordered over two orientations with occupancy factors 0.65:0.35 and 0.77:0.23. In the anion, six Br atoms and a μ2-acetate ligand form a strongly distorted cubic O2Br6 coordination polyhedron around the Re2 dinuclear centre. In the crystal, centrosymmetrically related ET cations and Re2O2Br6 anions are linked into dimers by π–π stacking inter­actions [centroid-to-centroid distance = 3.826 (8) Å] and by pairs of additional Re⋯Br contacts [3.131 (3) Å], respectively. The dimers are further packed into a three-dimensional network by non-directional inter­ionic electrostatic forces and by C—H⋯Br and C—H⋯S hydrogen bonds. The disordered 1,1,2-tri­chloro­ethane mol­ecules occupy solvent-accessible channels along the b axis.

This review paper is focused on the research of molecular mechanisms occurring in porphyrin-like systems such as porphyrins, phthalocyanines, and corroles as well as in chromophore-semiconductor quantum dot (QD-CdSe/ZnS) or corrole-fullerene (C60) as electron-donor-acceptor unites. The basic spectroscopic investigations describe properties of materials in organic solutions in the ultraviolet, visible, and infrared ranges and in a form of Langmuir and Langmuir–Blodgett molecular nanolayers to get knowledge on photophysics of dyes and the influence of QD and C60 on the electron redistribution within the molecular structures. The studies also allowed to explain the impact of solvent on the spectroscopic properties of corroles and on the redistribution of the π-electrons in the excited state. The fluorescence studies very evidently showed strong interaction between chromophores and C60 or QD and clearly demonstrated the strong donor-acceptor nature of the phthalocyanines-quantum dot and the corrole-fullerene dyad. In addition, spectroscopic studies in polarized light allowed determining molecular arrangement of the chromophore molecules in the Langmuir–Blodgett layers with respect to solid substrates. The computer calculations (TD-DFT theory) confirmed the experimental results, in particular the redistribution of the π-electrons in the excited state and the location of HOMO and LUMO levels. The DFT calculations let also to evaluate the reorganization energy values for the set of free-base corroles and C60 fullerene. In this review, it was shown the electron-donor-acceptor character of the systems composed of: porphyrin-quinone, phthalocyanines-QD, corroles-C60 dyads. It has been demonstrated potential capabilities of the photoactive organic materials with QD and fullerene in the future applications in many areas of optoelectronic and in the process of converting solar energy into electric energy in solar cells.

This paper examines the influence of aprotic solvents on the spectroscopic properties as well as the energy deactivation of two free-base corrole dyes substituted with C6F5 and/or 4-NO2C6H4 groups. Absorption, fluorescence and laser-induced optoacoustic spectroscopy have been used to follow the singlet and triplet states of fluorine corroles belonging to the A2B and A3 type in toluene (TL), chloroform (CL), dimethylformamide (DMF), dimethyl sulfoxide (DMSO) and also in solvent mixtures. Changes in the absorption and fluorescence spectra are influenced by the type of solvent mixture. The fluorescence behaviors of the two investigated corroles were extremely different - fluorescence of the nitro-corrole in TL is dramatically quenched in the presence of DMF. In contrast, fluorescence quenching of fluorine corroles in DMF-TL mixtures is substantially weakened. Absorption, fluorescence, triplet population as well as singlet oxygen generation parameters are evaluated. The spectral experimental data are supported by quantum chemical calculations - time-dependent density functional theory (TD-DFT) and cyclic voltammetry experiments. The presented results are discussed from a viewpoint of aggregation, tautomerization, and deprotonation effects occurring in the corroles.

An improved Langmuir method is described and applied to produce transparent, conductive and flexible single layer of multiwall carbon nanotubes. This paper presents properties of multiwall carbon nanotubes spread on water subphase and in a form of Langmuir–Schaefer layers on a quartz plate and on flexible polymeric foil. The results show very high homogeneity of the monolayers on a very large area obtained with the use of the proposed modified Langmuir method and indicate their relatively high radiation transmission and electrical conductivity. Laser scanning confocal and scanning electron microscopic images of the layers are presented. The microscopic visualization of the nanolayers is supported by spectroscopic studies (transmittance, photoacoustics) in the range from ultraviolet to mid-infrared. Moreover, electric measurements (current versus voltage characteristics) of the carbon material on the polymeric foil are presented. The obtained results of the investigated multiwall carbon nanotubes are discussed in a view of potential application in optoelectronics.

Experimental and theoretical studies on the structure and spectroscopic properties of the new Co(II) complexes [CoL1(NCS)2] (1) and [CoL2(NCS)2]·DMF (2), where L1 = N,N-bis(3,5-dimethylpyrazol-1-ymethyl)amine and L2 = N,N,N-tris(3,5-dimethylpyrazol-1-ylmethyl)amine, have been reported. The two N-scorpionate complexes were obtained in a one pot synthesis from a system containing zerovalent cobalt, 1-hydroxymethyl-3,5-dimethylpyrazole and NH4NCS, in the presence of MoO3 (1) and ZnCl2 (2). The most essential feature was the in situ formation of the two new multipodal organic ligands L1 and L2 in a condensation reaction between the starting ligand (1-hydroxymethyl-3,5-dimethylpyrazole) and ammonia. The crystal structures and electronic (UV–Vis), infrared (IR) and Raman spectra of the isolated complexes have been analyzed and discussed. The combined use of experiments and computations allowed a firm assignment of the majority of the observed electronic and vibrational transitions. Moreover, theoretical (DFT) calculations at the B3LYP/6–31G and B3LYP/LanL2DZ levels have been carried out to investigate the geometry of 1 and the in situ obtained ligands L1 and L2. Both experimental and theoretical methods provided results of reasonable compatibility.

The investigation presented in this paper deals with new free-base corroles substituted with different peripheral groups. These aromatic macrocycles were efficiently synthesized by a [2+1] approach from dipyrromethanes. Moreover, the basic spectroscopic studies of the dyes in chloroform were conducted, and the UV-Vis absorption, fluorescence and ESR parameters were estimated. The experimental data were supported by quantum chemical calculations. The presence of monomeric dye structures is concentration independent (10(-6)-10(-4) M), as expected for dyes in a solvent of low polarity, and rules out aggregate formation of corroles dissolved in chloroform. The excitation emission and fluorescence life-time values confirm the monomeric structure of the corroles. The spectra were compared with the time-dependent density functional theory (TD-DFT) results for the HOMO-LUMO states. The ESR examinations strongly show that for any type of studied fluorine corrole an unpaired electron is localized on the corrole macroring but not on the substituents both before and after light illumination. Laser illumination creates additional radicals, however with different effectiveness depending on the sample.

The optical, electro-physical and magnetic properties of the radical-anionic salt of the so-called simple composition – (N–CH3-2-NH2-5Cl-Py)(TCNQ) were investigated, (N–CH3-2-NH2-5Cl-Py – N-methyl-2-amine-5-chloro-pyridine). Raman’s scattering spectra and infrared reflection spectra are very similar to quasi-one-dimensional salts based on TCNQ. However, in our case, almost isolated π-dimers (TCNQ)22− are used instead of columns built with TCNQ. Supramolecular contacts involving the amine-cation group combine dimers into infinite chains and thereby reduce the local symmetry of the molecules TCNQ to C2h. These peculiarities of the structure may be the cause of this extraordinary behaviour and the manifestation of vibronic-interaction. The salt is a semiconductor, the temperature dependence of the electrical conductivity is subordinated to the Variable Range Hopping model. According to the ESR data, the salt exhibits weak antiferromagnetic properties.

Correction for ‘The influence of diameter of multiwalled carbon nanotubes on mechanical, optical and electrical properties of Langmuir–Schaefer films’ by Karol Rytel et al., Phys. Chem. Chem. Phys., 2020, DOI: 10.1039/d0cp03687k.

Three new anion-radical TCNQ salts with Zn and Ni 2,2′-bipyridine complexes and appropriate solvent were synthesized as well as structurally and spectrally investigated. Two of the salts show quasi-one dimensional organization of the anions and show distinct anisotropy of the polarized reflection spectra. Both infrared and Raman spectra were extensively investigated using various spectral methods and discussed. The origin of principal absorption IR bands as well as Raman scattering lines was explained according to our quantum chemical calculations.

New anion-radical TCNQ salts containing o-phenanthroline complex cations with metal ions and appropriate solvent molecules were structurally and spectrally investigated. Contrary to the majority of TCNQ salts the structure of the investigated salts do not contains anion-radical stacks. It was stated that anisotropy of Raman spectra is negligent whereas the form of IR absorption spectra suggests very weak electron–molecular vibrations couplings. On the other hand the IR spectra of the cations are dominated mainly by the vibrations of the phenanthroline ligands. The Raman spectra of the investigated salts are differentiated and are altogether unlike each other. Some bands of complex cations located between 1100 and 1650 cm−1 show particular character and can characterize metal–phenantroline cation.

Vibrational properties of two fullerene derivatives: C60TZ-OT-5 (1) and C60TH-3HX (2) have been studied using infrared absorption and Raman scattering spectroscopies. Additionally, quantum chemical calculations of the equilibrium geometry and normal mode vibrations of these functionalized fullerenes were performed. It was stated that despite of distinct structural differences between the investigated molecules, their experimental spectra are quite similar and correspond well with the calculated ones. The orientation of the molecules in the Langmuir–Blodgett films was evaluated.

Charge ordering in the quasi-one-dimensional organic conductors ${(\mathrm{TMTTF})}_{2}X\phantom{\rule{0.16em}{0ex}}(X=\mathrm{Sb}{\mathrm{F}}_{6},\mathrm{As}{\mathrm{F}}_{6},\mathrm{P}{\mathrm{F}}_{6})$ was studied by using Raman spectroscopy. In the charge-ordered phase three vibrational features related to the ring breathing mode ${\ensuremath{\nu}}_{10}({a}_{g})$ of neutral ($\mathrm{TMTT}{\mathrm{F}}^{0}$) and ionized ($\mathrm{TMTT}{\mathrm{F}}^{+0.5}$ and $\mathrm{TMTT}{\mathrm{F}}^{+1}$) are observed at about 503, 507, and $526\phantom{\rule{0.16em}{0ex}}\mathrm{c}{\mathrm{m}}^{\ensuremath{-}1}$, respectively. The bands of donor molecules with charge $+0.5e$ are assigned to ferroelectric domains while the bands of neutral and fully ionized molecules to domain walls. The shape of the band at about $526\phantom{\rule{0.16em}{0ex}}\mathrm{c}{\mathrm{m}}^{\ensuremath{-}1}$, attributed to the charged domain walls (molecules with charge $+1e$), reveals important differences between salts, i.e., indicates the presence of relaxor ferroelectricity which is well seen in ${(\mathrm{TMTTF})}_{2}\mathrm{P}{\mathrm{F}}_{6}$.

The application of ultraviolet, FT-IR and Raman spectra was proposed for identification studies of the newest penem analogs (doripenem, biapenem and faropenem). An identification of the newest penem analogs based on their separation from related substances was achieved after the application of first derivative of direct spectra in ultraviolet which permitted elimination of overlapping effects. A combination of experimental and theoretical studies was performed for analyzing the structure and vibrational spectra (FT-IR and Raman spectra) of doripenem, biapenem and faropenem. The calculations were conducted using the density functional theory with the B3LYP hybrid functional and 6-31G(d,p) basis set. The confirmation of the applicability of the DFT methodology for interpretation of vibrational IR and Raman spectra of the newest penem analogs contributed to determination of changes of vibrations in the area of the most labile bonds. By employing the theoretical approach it was possible to eliminate necessity of using reference standards which – considering the instability of penem analogs – require that correction coefficients are factored in.

The bichromophoric systems comprising of corrole and fullerene units and representing one of the rare cases of elaborate structures based on corrole have been studied with the use of photophysical methods. The dyad displays spectroscopic properties which are the superposition of the component spectra, indicating a very weak electronic coupling. Excitation of the corrole unit leads to charge redistribution. The results of UV–vis absorption and fluorescence and also fluorescence kinetics suggest the presence of charge separation. It was shown that light absorption of the corrole–fullerene dyad is better fitted to the sunlight spectrum than porphyrin. Electron paramagnetic resonance investigations suggest partial spin density redistribution at low temperature between corrole and fullerene in the dyad. Quantum chemical calculations support experimental results.

We present first systematic spectral studies of a new corrole–fullerene dyad and its components: modified corrole and suitable spacer. The infrared absorption and Raman scattering spectra were measured in polycrystalline samples, at room temperature. Quantum chemical calculation results were compared with the experimental IR and Raman spectra. An attribution of the strongest IR and Raman bands was proposed. It was found that the strongest excitations in the dyad are mainly related to the excitations of the modified corrole part with some influence from the spacer and fullerene parts.

The IR reflection–absorption spectra of Langmuir–Blodgett (LB) layers of the functionalized fullerenes: C 60 -fused N-methylpyrrolidine-5-(dodecyl)thiophene ( 1 ) and C 60 -fused N-methylpyrrolidine-5-(12-bromododecyl)thiophene ( 2 ) were investigated. It was shown that thin films of functionalized fullerenes are ordered and characteristic parts of the molecules are oriented. Their orientation was evaluated with a simple spectroscopic method. It was stated that bromine atom at the end of aliphatic chain of the sample 2 strongly influences the chain orientation. Similarly, the sulphur atom in the thiophene ring causes some bend of its plane.

A inexpensive and rapid isocratic LC method has been developed for the quantitative determination of tebipenem—a new β-lactam antibiotic. Stress degradation studies were performed on tebipenem in acidic (0.2 N hydrochloric acid) and basic (0.02 N sodium hydroxide) solutions, in a solution with oxidizing agent (3 % hydrogen peroxide), and in the solid state, during thermolysis and photolysis. For a chromatographic separation of tebipenem and its degradation products, a C-18 stationary phase and 12 mM ammonium acetate-acetonitrile (96:4 v/v) were used. A quantitative determination of tebipenem was carried out by using a PDA detector at 298 nm, with a flow rate of 1.2 mL min−1. The linear regression analysis for the calibration plots showed a good linear relationship (r = 0.999) in the concentration range 0.041–0.240 mg mL−1. The method demonstrated good precision (1.14–1.96 % RSD) and recovery (99.60–101.90 %). The limits of detection and quantitation were 9.69 and 29.36 μg mL−1, respectively. The analysis of tebipenem reactivity was supported by quantum chemical calculations based on the density functional theory (DFT). The analysis of the electron density of the HOMO and LUMO of tebipenem suggested the possibility of electron transport in the molecule during the degradation of bi-cyclic 4:5 fused penem rings.

New TCNQ salt [Fe(dipy) 3 ](TCNQ) 4 ·{(H 3 C) 2 CO} containing solvent molecules in the crystal structure was synthesized and characterized. The crystal structure can be described as formed from alternating [Fe(dipy) 3 ] 2+ cations and acetone molecules and two types of stacks of (TCNQ) 2 − dimers that are parallel one to another. Analysis of the vibrational IR absorption and Raman scattering spectra shows that the optical conductivity spectrum is highly anisotropic. It is characteristic for the salt under investigation that the bands attributed to [Fe(dipy) 3 ] 2+ cations are relatively strong. This effect is particularly distinct in the Raman scattering spectra.

The vibrational properties of two fullerene derivatives: C 60 -fused N -methylpyrrolidine-5-(12-bromododecyl)thiophenyl (C 60 TH-DcB) and its modification (C 60 TH-Dc) has been studied. The vibrational properties were determined using the Raman scattering and infrared absorption spectroscopies supported by the quantum chemical calculations. The difference between two investigated molecules is very subtle. In the C 60 TH-DcB there is a terminal bromine atom attached to the end of the alkyl chain, while in C 60 TH-Dc this one atom is absent. The differences in the experimental spectra of both molecules are rather small but clear and they correspond quite well with the calculation results. The quantum chemical calculations of the normal modes of vibration let us describe these fingerprints and assign them to the specific vibrations of various functional groups of the molecule.

The paper deals with thermodynamic and spectroscopic characterization of Langmuir layers of phthalocyanines substituted with different peripheral groups: copper(II) 2,9,16,23-tetra-tert-butyl-29H,31H-phthalocyanine, copper(II) 2,3,9,10,16,17,23,24-octakis(octyloxy)-29H,31H-phthalocyanine, copper(II) tetrakis(4-cumylphenoxy)phthalocyanine. The isotherms, compressibility and stability of the Langmuir layers are investigated. Molecular arrangement of the molecular skeleton on water substrate is also evaluated. The essential influence of the substituents attached to the phthalocyanine macroring on dye thermodynamic properties is shown. The in-situ absorption of the phthalocyanine monolayers and electronic absorption spectra of dye solution in chloroform support existence of aggregates which architecture depends on the dye molecular structure.

The electronic absorption spectra of fullerene–thiophene-derived dyads in the UV–vis range have been investigated and discussed taking into account the results of time-dependent density functional theory (TD-DFT) calculations. It was found that the strongest excitations in the dyads are mainly related to the excitations of the fullerene part with some influences from the thiophene-derived part and intramolecular charge transfer processes. The 3T–F dyad significantly differs from the others — the calculated HOMO–LUMO gap in this molecule is significantly lower than in other dyads. This difference is caused by the length of the oligomer and probably by the electron delocalization connected with that length.

The paper deals with spectral studies (IR absorption, IR reflection–absorption, Raman scattering, and electronic absorption) of Langmuir–Blodgett layers of selected fullerene–thiophene dyads; some information on preparation and properties of the layers are also given. The spectra were recorded with unpolarised and polarised light (p-polarisation and s-polarisation) to receive data on orientation of the dyads with respect to the solid substrate and on interaction of the dyads with gold substrates. The comparison of the dyad spectra suggests redistribution of charges in both moieties of the dyads after films deposition on the substrate. We have shown that the polarised reflection–absorption spectra of the thin films are strongly dependent on the light polarisation. From the analysis of the data on the basis of the results obtained from various spectral methods it was concluded that the Langmuir–Blodgett layers are ordered and some parts of the dyads are oriented.

The set of three new hydrogen bonding functionalized fullerenes containing amide (PCB-t-BA, PCB-n-BA, and MPCB-t-BA) was investigated using the infrared absorption and Raman scattering spectroscopies. Additionally, the quantum chemical calculations of the equilibrium geometry and normal mode vibrations of the molecules were performed. Role of hydrogen bonds (HB) in the investigated samples was under our particular attention. Bifurcated HB was suggested.

Spectral investigations of the new organic semiconductor of the formula (TMTSF)2[3,3′-Co(1,2-C2B9H11)2], were performed using Raman and quantum chemical simulation methods. The polarized Raman spectra of single crystals of the salt were recorded in the range 150–3100 cm−1. An assignment of the strongest vibrational Raman lines was proposed. The possibility of the presence of two rotamers of the Co anion has been discussed taking into account the DFT calculations and the experimental spectra of the reference material.

The group of six TCNQ salts with N -methyl derivatives of pyrazine, bearing up to four methyl groups in various pyrazine sites, was selected for the spectral studies. The influence of the spatial structure of the donors on the charge distribution on the acceptor as well as spectral features of adequate TCNQ salts were deduced. The stretching vibrations of the C C bonds (mode ν 4 ) were used for the evaluation of the charge density on the TCNQ − anions but the stretching vibrations of the C N bonds (mode ν 2 ) indicate a diversity of the neighborhood of TCNQ species. It was shown that for the salts containing nonequivalent TCNQ anions the band ν 2 is splitted; each component of the multiplet seen in the IR and Raman spectra represents various environment of the anion. On the other hand the splitted mode ν 4 indicates an existence of TCNQ − anions differently charged. Thus, it was shown that the spectral methods are suitable for indicating nonequivalence of the TCNQ in their salts.

New dyads of the fullerene C 60 with ethylenedioxythiophenyl ( EDOT ) and hexylthiophenyl ( HXT ) groups were investigated using the infrared absorption and Raman scattering spectroscopies. The experimental methods were supported by the quantum chemical calculations of the equilibrium geometry and normal mode vibrations of the dyads. Taking into account the results of normal modes calculations, the description of the observed absorption bands and Raman lines are proposed. It was shown, that change in molecular structure of the dye leads to specific changes in the IR spectra. Spectrally observed effects authorized us to state that infrared absorption spectroscopy can be successfully used for characterization of such complex molecular systems as thiophene–fullerene dyads.

Infrared and Raman investigations of two phases of bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) based organic conductors with the same CF3CF2SO3− anion: β′-(BEDT-TTF)2CF3CF2SO3 and δ′-(BEDT-TTF)2CF3CF2SO3, are shortly reviewed and compared with the most typical infrared properties of the family of (BEDT-TTF)2RR′SO3 organic conductors, where R = SF5, CF3, and R′ are CH2, CF2, CHF, CHFCF2, and CH2CF2. The role of the molecular structur and spatial organization of the counterions is discussed.