Search Results (21)

Anodic aluminum oxide (AAO) is a promising material for sensor applications due to its unique nanoporous structure and high surface area. This study investigates enhancing AAO’s sensing capabilities by incorporating carbyne-enriched nanomaterials. This research aimed to create a novel surface acoustic wave (SAW) sensor with improved performance characteristics. AAO films were fabricated using a two-step anodization process, followed by carbyne-enriched coating deposition via ion-assisted pulse-plasma deposition. The dielectric properties of the resulting composite material were characterized using impedance spectroscopy, while the sensing performance was evaluated by exposing the sensor to various ethanol concentrations. The results showed a significant increase in capacitance and dielectric permittivity for the carbyne-filled AAO compared to pristine AAO, along with a 5-fold improvement in sensitivity to ethanol vapor. The increased sensitivity is attributed to the synergistic combination of the AAO’s high surface area and the carbyne’s unique electrical properties. This work demonstrates the successful fabrication and characterization of a novel high-sensitivity gas sensor, highlighting the potential of carbyne-enriched AAO for advanced sensor applications. Full article

We conducted a joint synthetic, spectroscopic and computational study to explore the reactivity towards cyanide (from Bu₄NCN) of a series of dinuclear complexes based on the M₂Cp₂(CO)₃ scaffold (M = Fe, Ru; Cp = η⁵-C₅H₅), namely [M₂Cp₂(CO)₂(µ-CO){µ,η¹:η²-CH=C=CMe₂}]BF₄ (1Fe-Ru), [Ru₂Cp₂(CO)₂(µ-CO){µ,η¹:η²-C(Ph)=CHPh}]BF₄ (2Ru) and [M₂Cp₂(CO)₂(µ-CO){µ-CN(Me)(R)}]CF₃SO₃ (3Fe-Ru). While the reaction of 1Fe with Bu₄NCN resulted in prevalent allenyl deprotonation, preliminary CO-NCMe substitution in 1Ru enabled cyanide addition to both the allenyl ligand (resulting in the formation of a h¹:h²-allene derivative, 5A) and the two metal centers (affording 5B1 and 5B2). The mixture of 5B1-2 was rapidly converted into 5A in heptane solution at 100 °C, with 5A being isolated with a total yield of 60%. Following carbonyl-chloride substitution in 2Ru, CN⁻ was incorporated as a terminal ligand upon Cl⁻ displacement, to give the alkenyl complex 6 (84%). The reactivity of 3Fe and 3Ru is strongly influenced by both the metal element, M, and the aminocarbyne substituent, R. Thus, 7aRu was obtained with a 74% yield from cyanide attack on the carbyne in 3aRu (R = Cy, cyclohexyl), whereas the reaction involving the diiron counterpart 3aFe yielded an unclean mixture of the metastable 7aFe and the CO/CN⁻ substitution product 8aFe. The cyano-alkylidene complexes 7aRu (R = Cy) and 7bFe (R = Me) underwent CO loss and carbene to carbyne conversion in isopropanol at 60–80 °C, giving 8aRu (48%) and 8bFe (71%), respectively. The novel compounds 5A, 5B1-2, 6 and 7aRu were characterized by IR and NMR spectroscopy, with the structure of 7aRu further elucidated by single crystal X-ray diffraction analysis. Additionally, the DFT-optimized structures of potential isomers of 5A, 5B1-2 and 6 were calculated. Full article

The response characteristics of carbyne-enriched surface-acoustic-wave (SAW)-based gas sensors utilizing meander and rectangular microheater topologies were investigated to assess their desorption and recovery properties. Comparative analysis of contact resistance and interface capacitance before and after heating revealed minimal deviation in contact resistance, signifying strong thermal stability in the carbyne-enriched layer. However, the interface capacitance varied with the microheater size. Our analysis reveals that a small meander microheater configuration (line width: 300 µm) facilitates efficient sensor recovery at ethanol concentration measurements in the range of 180–680 ppm, maintaining a low deviation in time delay across different concentrations (~2.3%), resulting in a narrow hysteresis and linear sensor response. Conversely, the large meander microheater (line width: 450 µm) and rectangular dense microheater induce irreversible changes in the sensing structure, leading to a widened hysteresis at higher concentrations and increased power consumption. Recovery patterns display substantial deviations from initial values at different concentration levels. Higher concentrations exhibit broader hysteresis, while lower concentrations show narrower hysteresis loops, compared to the small meander microheater. The study offers insights into desorption rates, power consumption variations, and recovery behaviors related to different microheater configurations. It demonstrates the importance of microheater topology selection in tailoring recovery properties and response characteristics, contributing to the advancement of carbyne-based sensor technology. Full article

A convenient synthesis of [HB(HImMe)₃](PF₆)₂ (ImMe = N-methylimidazolyl) is decribed. This salt serves in situ as a precursor to the tris(imidazolylidenyl)borate Li[HB(ImMe)₃] pro-ligand upon deprotonation with ⁿBuLi. Reaction with [W(≡CC₆H₄Me-4)(CO)₂(pic)₂(Br)] (pic = 4-picoline) affords the carbyne complex [W(≡CC₆H₄Me-4)(CO)₂{HB(ImMe)₃}]. Interrogation of experimental and computational data for this compound allow a ranking of familiar tripodal and facially coordinating ligands according to steric (percentage buried volume) and electronic (ν_CO) properties. The reaction of [W(≡CC₆H₄Me-4)(CO)₂{HB(ImMe)₃}] with [AuCl(SMe₂)] affords the heterobimetallic semi-bridging carbyne complex [WAu(μ-CC₆H₄Me-4)(CO)₂(Cl){HB(ImMe)₃}]. Full article

Metallization for contacts in organic electronic nanodevices is of great importance for their performance. A lot of effects can appear at the contact/organic interface and modify the contact parameters, such as contact resistance, adhesive strength, and bonding ability. For novel materials, it is important to study the interactions with metal atoms to develop a suitable technology for contacts, fulfilling to the greatest extent the above-mentioned parameters. A novel material is carbyne, which is still under intensive research because of its great potential in electronics, especially for sensing applications. However, the most appropriate metallization strategy for carbyne-based devices is still unknown, so the interactions between carbyne and metal films should be studied to more precisely direct the development of the metallization technology, and to form contacts that are not limiting factors for device performance. Full article

Pulsed Laser Deposition (PLD) is a highly flexible experimental methodology for the growth of thin films of a broad variety of materials, based on the generation of laser-induced plasmas (LIP) with material ablated from a solid target and on the transfer of the ablated material to a substrate. This review is focused on carbon-based materials—specifically, diamond-like carbon (DLC), graphene and carbyne—and will both discuss the influence of the most critical experimental parameters on the obtained materials and present the experimental developments proposed in the recent literature to tailor the properties of the deposited films and optimize the standard PLD technique for production of various carbon-based materials. Full article

We report a broad theoretical study on [(PMe₃)₃MER]⁺ complexes, with M = Ni, Pd, Pt, E = C, Si, Ge, Sn, Pb, and R = Ar^Mes, Tbb, (Ar^Mes = 2,6-dimesitylphenyl; Tbb = C₆H₂-2,6-[CH(SiMe₃)₂]₂-4-^tBu). A few years ago, our group succeeded in obtaining heavier homologues of cationic group 10 carbyne complexes via halide abstraction of the tetrylidene complexes [(PMe₃)₃M=E(X)R] (X = Cl, Br) using a halide scavenger. The electronic structure and the M-E bonds of the [(PMe₃)₃MER]⁺ complexes were analyzed utilizing quantum-chemical tools, such as the Pipek–Mezey orbital localization method, the energy decomposition analysis (EDA), and the extended-transition state method with natural orbitals of chemical valence (ETS-NOCV). The carbyne, silylidyne complexes, and the germylidyne complex [(PMe₃)₃NiGeAr^Mes]⁺ are suggested to be tetrylidyne complexes featuring donor–acceptor metal tetrel triple bonds, which are composed of two strong π(M→E) and one weaker σ(E→M) interaction. In comparison, the complexes with M = Pd, Pt; E = Sn, Pb; and R = Ar^Mes are best described as metallotetrylenes and exhibit considerable M−E−C bending, a strong σ(M→E) bond, weakened M−E π-components, and lone pair density at the tetrel atoms. Furthermore, bond cleavage energy (BCE) and bond dissociation energy (BDE) reveal preferred splitting into [M(PMe₃)₃]⁺ and [ER] fragments for most complex cations in the range of 293.3–618.3 kJ·mol⁻¹ and 230.4–461.6 kJ·mol⁻¹, respectively. Finally, an extensive study of the potential energy hypersurface varying the M−E−C angle indicates the presence of isomers with M−E−C bond angles of around 95°. Interestingly, these isomers are energetically favored for M = Pd, Pt; E = Sn, Pb; and R = Ar^Mes over the less-bent structures by 13–29 kJ·mol⁻¹. Full article

Transistors made up of carbon nanotube CNT have demonstrated excellent current–voltage characteristics which outperform some high-grade silicon-based transistors. A continuously tunable energy barrier across semiconductor interfaces is desired to make the CNT-based transistors more robust. Despite that the direct band gap of the carbyne inside a CNT can be widely tuned by strain, the size of the carbyne cannot be controlled easily. The production of a monoatomic chain with more than 6000 carbon atoms is an enormous technological challenge. To predict the optimal chain length of a carbyne in different molecular environments, we have developed a Monte Carlo model in which a finite-length carbyne with a size of 4000–15,000 atoms is encapsulated by a CNT at finite temperatures. Our simulation shows that the stability of the carbyne@nanotube is strongly influenced by the nature and porosity of the CNT, the external pressure, the temperature, and the chain length. We have observed an initiation of the chain-breaking process in a compressed carbyne@nanotube. Our work provides much-needed input for optimizing the carbyne length to produce carbon chains much longer than 6000 atoms at ~300 K. Design rules are proposed for synthesizing ~1% strained carbyne@(6,5)CNT as a component in CNT-based transistors to tune the energy barriers continuously. Full article

Using laser-induced vaporisation to evaporate and ionise a source of curved polyaromatic hydrocarbons (carbon nanobelts), we show collision impacts between species cause mass loss and the resultant ions are catalogued via mass-spectrometry. These data are interpreted via a series of “in-silico”-simulated systematic hydrogen-loss studies using density functional theory modelling, sequentially removing hydrogen atoms using thermodynamic stability as a selection for subsequent dehydrogenation. Initial hydrogen loss results in the formation of carbyne chains and pentagon-chains while the nanobelt rings are maintained, giving rise to new circular strained dehydrobenzoannulene species. The chains subsequently break, releasing CH and C₂. Alternative routes towards the formation of closed-cages (fullerenes) are identified but shown to be less stable than chain formation, and are not observed experimentally. The results provide important information on collision degradation routes of curved molecular carbon species, and notably serve as a useful guide to high-energy impact conditions observed in some astrochemical environments. Full article

Due to the unique combination of physicochemical and structural properties of carbyne-enriched nanocoatings, they can be used for the development of high-end electronic devices. We propose using it for the development of sensor platforms based on silicon bulk micromachined membranes that serve as a part of microcapacitors with flexible electrodes, with various sizes and topologies. The carbyne-enriched nanocoating was grown using the ion-assisted pulse-plasma deposition method in the form of 2D-ordered linear-chain carbon with interchain spacing in the range of approximately 4.8–5.03 Å. The main characteristics of the fabricated sensors, such as dynamic range, sensitivity, linearity, response, and recovery times, were measured as a function of the ethanol concentration and compared for the different sizes of the micromembranes and for the different surface states, such as patterned and non-patterned. The obtained results are the first step in the further optimization of these sensor platforms to reach more precise detection of volatile organic compounds for the needs of the healthcare, air monitoring, and other relevant fields of human health. Full article

The application of carbyne-enriched nanomaterials opens unique possibilities for enhancing the functional properties of several nanomaterials and unlocking their full potential for practical applications in high-end devices. We studied the ethanol-vapor-sensing performance of a carbyne-enriched nanocoating deposited onto surface acoustic wave (SAW) composite substrates with various electrode topologies. The carbyne-enriched nanocoating was grown using the ion-assisted pulse-plasma deposition technique. Such carbon nanostructured metamaterials were named 2D-ordered linear-chain carbon, where they represented a two-dimensionally packed hexagonal array of carbon chains held by the van der Waals forces, with the interchain spacing approximately being between 4.8 and 5.03 Å. The main characteristics of the sensing device, such as dynamic range, linearity, sensitivity, and response and recovery times, were measured as a function of the ethanol concentration. To the authors’ knowledge, this was the first time demonstration of the detection ability of carbyne-enriched material to ethanol vapors. The results may pave the path for optimization of these sensor architectures for the precise detection of volatile organic compounds, with applications in the fields of medicine, healthcare, and air composition monitoring. Full article

Background: Due to the aging of the world population, the number of joint diseases, along with the number of arthroplasties, has increased, simultaneously increasing the amount of complications, including periprosthetic joint infection (PPI). In this study, to combat a PPI, we investigated the antimicrobial properties of the new composite cover for titanium implants, silver-doped carbyne-like carbon (S-CLC) film. Methods: The first assay investigated the antimicrobial activity against Pseudomonas aeruginosa and releasing of silver ions from S-CLC films into growth media covered with S-CLC with a thickness of 1, 2, and 4 mm. The second assay determined the direct antibacterial properties of the S-CLC film’s surface against Staphylococcus aureus, Enterococcus faecalis, or P. aeruginosa. The third assay studied the formation of microbial biofilms of S. aureus or P. aeruginosa on the S-CLC coating. Silver-doped carbyne-like carbon (S-CLC)-covered or titanium plates alone were used as controls. Results: S-CLC films, compared to controls, prevented P. aeruginosa growth on 1 mm thickness agar; had direct antimicrobial properties against S. aureus, E. faecalis, and P. aeruginosa; and could prevent P. aeruginosa biofilm formation. Conclusions: S-CLC films on the Ti surface could successfully fight the most common infectious agent in PPI, and prevented biofilm formation. Full article

Carbon nanomaterials, such as carbon nanotubes (CNTs), graphene sheets (GSs), and carbyne, are an important new class of technological materials, and have been proposed as nano-mechanical sensors because of their extremely superior mechanical, thermal, and electrical performance. The present work reviews the recent studies of carbon nanomaterials-based nano-force and nano-mass sensors using mechanical analysis of vibration behavior. The mechanism of the two kinds of frequency-based nano sensors is firstly introduced with mathematical models and expressions. Afterward, the modeling perspective of carbon nanomaterials using continuum mechanical approaches as well as the determination of their material properties matching with their continuum models are concluded. Moreover, we summarize the representative works of CNTs/GSs/carbyne-based nano-mass and nano-force sensors and overview the technology for future challenges. It is hoped that the present review can provide an insight into the application of carbon nanomaterials-based nano-mechanical sensors. Showing remarkable results, carbon nanomaterials-based nano-mass and nano-force sensors perform with a much higher sensitivity than using other traditional materials as resonators, such as silicon and ZnO. Thus, more intensive investigations of carbon nanomaterials-based nano sensors are preferred and expected. Full article

The acyclic organic alkynes and carbyne bonds exhibit linear shapes. Metallabenzynes and metallapentalynes are six- or five-membered metallacycles containing carbynes, whose carbine-carbon bond angles are less than 180°. Such distortion results in considerable ring strain, resulting in the unprecedented reactivity compared with acyclic carbynes. Meanwhile, the aromaticity of these metallacycles would stabilize the ring system. The fascinating combination of ring strain and aromaticity would lead to interesting reactivities. This mini review summarized recent findings on the reactivity of the metal–carbon triple bonds and the aromatic ring system. In the case of metallabenzynes, aromaticity would prevail over ring strain. The reactions are similar to those of organic aromatics, especially in electrophilic reactions. Meanwhile, fragmentation of metallacarbynes might be observed via migratory insertion if the aromaticity of metallacarbynes is strongly affected. In the case of metallapentalynes, the extremely small bond angle would result in high reactivity of the carbyne moiety, which would undergo typical reactions for organic alkynes, including interaction with coinage metal complexes, electrophilic reactions, nucleophilic reactions and cycloaddition reactions, whereas the strong aromaticity ensured the integrity of the bicyclic framework of metallapentalynes throughout all reported reaction conditions. Full article

We investigate hole transfer in open carbynes, i.e., carbon atomic nanowires, using Real-Time Time-Dependent Density Functional Theory (RT-TDDFT). The nanowire is made of N carbon atoms. We use the functional B3LYP and the basis sets 3-21G, 6-31G*, cc-pVDZ, cc-pVTZ, cc-pVQZ. We also utilize a few Tight-Binding (TB) wire models, a very simple model with all sites equivalent and transfer integrals given by the Harrison $pp\pi$ expression (TBI) as well as a model with modified initial and final sites (TBImod) to take into account the presence of one or two or three hydrogen atoms at the edge sites. To achieve similar site occupations in cumulenes with those obtained by converged RT-TDDFT, TBImod is sufficient. However, to achieve similar frequency content of charge and dipole moment oscillations and similar coherent transfer rates, the TBImod transfer integrals have to be multiplied by a factor of four (TBImodt4times). An explanation for this is given. Full geometry optimization at the B3LYP/6-31G* level of theory shows that in cumulenes bond length alternation (BLA) is not strictly zero and is not constant, although it is symmetrical relative to the molecule center. BLA in cumulenic cases is much smaller than in polyynic cases, so, although not strictly, the separation to cumulenes and polyynes, approximately, holds. Vibrational analysis confirms that for N even all cumulenes with coplanar methylene end groups are stable, for N odd all cumulenes with perpendicular methylene end groups are stable, and the number of hydrogen atoms at the end groups is clearly seen in all cumulenic and polyynic cases. We calculate and discuss the Density Functional Theory (DFT) ground state energy of neutral molecules, the CDFT (Constrained DFT) “ground state energy” of molecules with a hole at one end group, energy spectra, density of states, energy gap, charge and dipole moment oscillations, mean over time probabilities to find the hole at each site, coherent transfer rates, and frequency content, in general. We also compare RT-TDDFT with TB results. Full article