Construction of hierarchical NiCo2 S4 /2D-Carbyne nanohybrid onto nickel foam for high performance supercapacitor and non-enzymatic electrochemical glucose sensor applications.

Synthesising and designing pseudocapacitive material with good electrochemical and electrocatalytic behaviour is essential to use as supercapacitor as well as non-enzymatic glucose sensor electrode. In this work, NiCo2 S4 nanoparticles decorated onto the 2D-Carbyne nanosheets are achieved by the solvothermal process. The as-prepared NiCo2 S4 @2D-Carbyne provides rich reaction sites and better diffusion pathways. On usage as an electrode for supercapacitor application, the NiCo2 S4 @2D-Carbyne exhibits the specific capacitance of about 2507 F g-1 at 1 A g-1 . In addition, the fabricated hybrid device generates an energy density of 52.2 Wh kg-1 at a power density of 1.01 kW kg-1 . Besides, the glucose oxidation behaviour of NiCo2 S4 @2D-Carbyne modified GCE has also been performed. The diffusion of glucose from the electrolyte to the electrode obeys the kinetic control process. Furthermore, the fabricated NiCo2 S4 @2D-Carbyne non-enzymatic glucose sensor exhibits a limit of detection of about 34.5 µM with a sensitivity of about 135 µA mM-1 cm-2 . These findings highlight the need to design and synthesis electrode materials with adequate electrolyte-electrode contact, strong structural integrity, and rapid ion/electron transport.

Synthesis and Characterization of a Rhenanaphthalene Isomer.

Exploration of organometallic metallacycles has led to the development of various polycyclic compounds with fascinating structures, which could be used as functional materials. In this work, a new rhenanaphthalene isomer was isolated from the reaction of ReH5 (PMe2 Ph)3 with o-ethynylphenyl alkyne in the presence of excess HCl. Its structure was then identified using the single-crystal X-ray diffraction and NMR spectroscopy. DFT studies suggest that its formation involves two protonation reactions and two migration reactions. This new rhenanaphthalene isomer enriches the family of metallacycles.

Tip-Enhanced Stokes-Anti-Stokes Scattering from Carbyne.

Carbyne, a linear chain of carbon atoms, is the truly one-dimensional allotrope of carbon and the strongest known Raman scatterer. Here, we use tip-enhanced Raman scattering (TERS) to further enhance the Raman response of a single carbyne chain confined inside a double-walled carbon nanotube. We observe an increase of the anti-Stokes scattering by a factor of 3290 and a 22-fold enhancement of the anti-Stokes/Stokes ratio relative to far-field measurements. The power dependence of the anti-Stokes/Stokes ratio under TERS conditions is indicative of coherent Stokes-anti-Stokes scattering mediated by an excited phonon. The role of resonance effects and laser-induced heating are discussed and potential opportunities are outlined.

Poly(imidazolyliden-yl)borato Complexes of Tungsten: Mapping Steric vs. Electronic Features of Facially Coordinating Ligands.

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 (νCO) 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}].

Overview of the Metallization Approaches for Carbyne-Based Devices.

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.

Stable Ketenyl Anions via Ligand Exchange at an Anionic Carbon as Powerful Synthons.

Under an atmosphere of carbon monoxide (CO), a (phosphino)diazomethyl anion salt [[P]-CN2 ][K(18-C-6)(THF)] (1) ([P]=[(CH2 )(NDipp)]2 P; 18-C-6=18-crown-6; Dipp=2,6-diisopropylphenyl) undergoes a facile N2 /CO exchange reaction giving the (phosphino)ketenyl anion salt [[P]-CCO][K(18-C-6)] (2). Oxidation of 2 with elemental Se affords the (selenophosphoryl)ketenyl anion salt [P](Se)-CCO][K(18-C-6)] (3). These ketenyl anions feature a strongly bent geometry at the P-bound carbon and this carbon atom is highly nucleophilic. The electronic structure of the ketenyl anion [[P]-CCO]- of 2 is examined by theoretical studies. Reactivity investigations demonstrate 2 as a versatile synthon for derivatives of ketene, enolate, acrylate and acrylimidate moieties.

Toward Confined Carbyne with Tailored Properties.

Confining carbyne to a space that allows for stability and controlled reactivity is a very appealing approach to have access to materials with tunable optical and electronic properties without rival. Here, we show how controlling the diameter of single-walled carbon nanotubes opens the possibility to grow a confined carbyne with a defined and tunable band gap. The metallicity of the tubes has a minimal influence on the formation of the carbyne, whereas the diameter plays a major role in the growth. It has been found that the properties of confined carbyne can be tailored independently from its length and how these are mostly determined by its interaction with the carbon nanotube. Molecular dynamics simulations have been performed to interpret these findings. Furthermore, the choice of a single-walled carbon nanotube host has been proven crucial even to synthesize an enriched carbyne with the smallest energy gap currently reported and with remarkable homogeneity.

Electrospun Polymer-Derived Carbyne Supercapacitor for Alternating Current Line Filtering.

The filtering device is a vital component of electronic goods that rectifies ripples which occur upon converting alternating current (AC) to direct current (DC) and attenuates high-frequency noise during switching or voltage declines. Classical filtering devices suffer from low performance metrics and are bulky, limiting their use in modern electronic devices. The fabrication process of electrode materials for high-frequency symmetric supercapacitor (HFSSC) is complicated, hindering commercialization. Herein, for the first time, the design of a high-performance stand-alone carbyne film comprised of sp/sp2 -hybridized carbon as an electrode for AC filtering under a wide frequency range is reported. The carbyne film as HFSSC shows the ideal capacitive behavior at ultrahigh scan rate of 10 000 V s-1 with excellent linearity which is top among the reported AC line filter capacitor. The carbyne HFSSC exhibits a high energy density of 703.25 µF V2  cm-2 at 120 Hz, which is superior to that of current commercial electrolytic filters and many reported AC line supercapacitors. As a proof of concept, a carbyne device is implemented in a real time AC to DC adaptor that demonstrates excellent filtering performance at high frequencies.

Review on Carbon Nanomaterials-Based Nano-Mass and Nano-Force Sensors by Theoretical Analysis of Vibration Behavior.

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.

Raman Scattering Cross Section of Confined Carbyne.

We experimentally quantify the Raman scattering from individual carbyne chains confined in double-walled carbon nanotubes. We find that the resonant differential Raman cross section of confined carbyne is on the order of 10-22 cm2 sr-1 per atom, making it the strongest Raman scatterer ever reported.

Isotopic Labelling of Confined Carbyne.

Carbyne is a one-dimensional allotrope of carbon consisting of a linear chain of carbon atoms bonded to each other with exceptional strength. Its outstanding mechanical, optical, and electronic properties have been theoretically predicted, but its stability has only been achieved when grown encapsulated in the hollow core of carbon nanotubes. One of the advantages of this confinement is that its properties can be controlled by the chain's length and surrounding environment. We investigated an alternative way of gaining control of its properties is using isotope labelling as tuning mechanism. The optimized liquid precursor was first chosen among several options, which can greatly enhance the yield of the confined carbyne. Then isotopic labelled liquid precursor was encapsulated for further synthesis of isotopic labelled confined carbyne. This allowed us to obtain pioneering results on isotope engineered carbyne with around 11.9 % of 13 C-labelling using 13 C-methanol as precursor.

In Search of Fulminate Analogues: Ln M≡CP=NR.

The "CPNR" ligand may be viewed as being isolobal with fulminate, CNO; however, attempts to prepare a complex of such a ligand resulted instead in a range of novel imino and aminophosphinocarbyne complexes. Sequential treatment of [Mo(≡CBr)(CO)2 (Tp*)] (Tp*=hydrotris(dimethylpyrazolyl)borate) with nBuLi and ClP=NMes* (Mes*=C6 H2 tBu3 -2,4,6) afforded mixtures of the complexes [Mo(≡CPnBuNHMes*)(CO)2 (Tp*)] and traces of the bimetallic products [Mo2 {µ2 -C2 P2 O(NHMes)2 }(CO)4 (Tp*)2 ] and [Mo2 (µ2 -C2 PNHMes)(CO)4 (Tp*)2 ]. The reaction of [W(≡CBr)(CO)2 (Tp*)] with nBuLi and ClP=NMes* afforded predominantly the mononuclear carbyne [W{≡CP(=NMes*)nBu2 })(CO)2 (Tp*)] and traces of the binuclear complex [W2 (µ-C2 PNHMes)(CO)4 (Tp*)2 ] which is also obtained when tBuLi is used. Although not isolable, the intended complexes [M(≡CPNMes*)(CO)2 (Tp*)] could be generated in situ and spectroscopically characterized via the reactions of the stannyl carbynes [M(≡CSnnBu3 )(CO)2 (Tp*)] and ClP=NMes*. The preceding observations are mechanistically interpreted with reference to a computational interrogation of the model complex [Mo(≡CP=NCH3 )(CO)2 (Tp*)], the LUMO of which has considerable phosphorus character.

Revisiting the Intriguing Electronic Features of the BeOBeC Carbyne and Some Isomers: A Quantum-Chemical Assessment.

Extensive high-level quantum-chemical calculations reveal that the rod-shaped molecule BeOBeC, which was recently generated in matrix experiments, exists in two nearly isoenergetic states, the 5 Σ quintet (5 6) and the 3 Σ triplet (3 6). Their IR features are hardly distinguishable at finite temperature. The major difference concerns the mode of spin coupling between the terminal beryllium and carbon atoms. Further, the ground-state potential-energy surface of the [2Be,C,O] system at 4 K is presented and differences between the photochemical and thermal behaviors are highlighted. Finally, a previously not considered, so far unknown C2v -symmetric rhombus-like four-membered ring 3 [Be(O)(C)Be] (3 5) is predicted to represent the global minimum on the potential-energy surface.

Carbon Nanotube Chirality Determines Properties of Encapsulated Linear Carbon Chain.

Long linear carbon chains (LLCCs) encapsulated inside double-walled carbon nanotubes (DWCNTs) are regarded as a promising realization of carbyne, the truly one-dimensional allotrope of carbon. While the electronic and vibronic properties of the encapsulated LLCC are expected to be influenced by its nanotube host, this dependence has not been investigated experimentally so far. Here we bridge this gap by studying individual LLCCs encapsulated in DWCNTs with tip-enhanced Raman scattering (TERS). We reveal that the nanotube host, characterized by its chirality, determines the vibronic and electronic properties of the encapsulated LLCC. By choice of chirality, the fundamental Raman mode (C-mode) of the chain is tunable by ∼95 cm-1 and its band gap by ∼0.6 eV, suggesting this one-dimensional hybrid system to be a promising building block for nanoscale optoelectronics. No length dependence of the chain's C-mode frequency is evident, making LLCCs a close to perfect representation of carbyne.

Dimetallapoly-yn-diylidynes: Ln M≡C-(C≡C)x -C≡MLn (x=0-4).

Synthetic routes to dimetallated Cx carbon wires in which two metals are separated by a linear carbon chain involving terminal metal-carbon triple bonds are described for the complexes [(Tp*)(CO)2 W≡C-(C≡C)n -C≡W(CO)2 (Tp*)] (Tp*=hydrotris(dimethylpyrazolyl)borate) where n=1, 3 or 4, joining the previously known examples with n=0, 1 and 2 to complete the series as models for linear carbyne C∞ .

Bi- and Polynuclear Transition-Metal Carbon Tellurides.

The first examples of bi- and polynuclear tellurocarbonyl complexes were obtained from the reactions of [W(≡CTe)(CO)2 (Tp*)]NEt4 (Tp*=hydrotris(dimethylpyrazolyl)borate) with [MCl(PCy3 )]/TlPF6 (M=Cu, Au) or [Au2 Cl2 (µ-dppm)], which afford [WM(µ-CTe)(PCy3 )(CO)2 (Tp*)] (M=Cu, Au) and [WAu2 (µ-CTe)(µ-dppm)(CO)2 (Tp*)]3 (PF6 )3 . In all cases it is specifically the tellurocarbonyl that assumes a bridging, but in each case distinct, role including examples of isotellurocarbonyl, semi-bridging and σ-π coordination and combinations thereof. Tetrametallic complexes bridged by C2 Te and C2 Te2 ligands are also described.

Flexible Platinum(0) Coordination to a Ditungsten Ethanediylidyne.

The lithiocarbyne [W(≡CLi)(CO)2 (Tp*)] (Tp*=hydrotris(3,5-dimethylpyrazol-1-yl)borate) reacts with [PtCl2 (L2 )] (L2 =1,5-cyclo-octadiene, norbornadiene) to furnish ditungsten ethanediylidyne complexes, [W2 {µ-C2 Pt(L2 )}(CO)4 (Tp*)2 ], wherein a trigonal platinum(0) center unsymmetrically ligates one W≡C bond in the solid state but rapidly shimmies between the two W≡C bonds in solution. The η4 -dienes are displaced by monodentate CO or isocyanide ligands to provide derivatives where both W≡C bonds coordinate to a single Pt0 center, attended by significant distortion of the WCCW spine.

Rhenium-Promoted C-C Bond-Cleavage Reactions of Internal Propargyl Alcohols.

The first examples of C-C bond cleavage reactions of internal propargyl alcohols to give vinylidene complexes are described. Treatment of [Re(dppm)3 ]I with RC≡CC(OH)R'R'' (R=aryl, alkyl; C(OH)R'R''=C(OH)Ph2, C(OH)Me2 , C(OH)HPh, C(OH)H2 ) produced the vinylidene complexes ReI(=C=CHR)(dppm)2 with the elimination of C(O)R'R''. Computational studies support that the reactions proceed through a ß-alkynyl elimination of alkoxide intermediates Re{OC(R')(R'')C≡CR}(dppm)2 .

Proton-Coupled Reduction of an Iron Cyanide Complex to Methane and Ammonia.

Nitrogenase enzymes mediate the six-electron reductive cleavage of cyanide to CH4 and NH3 . Herein we demonstrate for the first time the liberation of CH4 and NH3 from a well-defined iron cyanide coordination complex, [SiP(iPr) 3 ]Fe(CN) (where [SiP(iPr) 3 ] represents a tris(phosphine)silyl ligand), on exposure to proton and electron equivalents. [SiP(iPr) 3 ]Fe(CN) additionally serves as a useful entry point to rare examples of terminally-bound Fe(CNH) and Fe(CNH2 ) species that, in accord with preliminary mechanistic studies, are plausible intermediates of the cyanide reductive protonation to generate CH4 and NH3 . Comparative studies with a related [SiP(iPr) 3 ]Fe(CNMe2 ) complex suggests the possibility of multiple, competing mechanisms for cyanide activation and reduction.

A direct, modular, and efficient construction of the P-C-P structural motif through coupling of manganese carbyne complexes with phosphines.

Easily available carbyne complexes of manganese were used as a source of carbyne fragments in an unconventional synthesis of backbone-substituted diphosphinomethanes and cyclic P-ylides upon coupling with secondary or tertiary phosphines, respectively, followed by demetalation under mild conditions.