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Research on lithium metal as a high-capacity anode for future lithium metal batteries (LMBs) is currently at an all-time high. To date, the different influences of a highly pure argon glovebox (GB) and an industry-relevant ambient dry room (DR) atmosphere have received little attention in the scientific community. In this paper, we report on the impact of in coin cell atmosphere (ICCA) on the performance of an LMB as well as its interphase characteristics and properties in combination with three organic carbonate-based electrolytes with and without two well-known interphase-forming additives, namely fluoroethylene carbonate (FEC) and vinylene carbonate (VC). The results obtained from this carefully executed systematic study show a substantial impact of the ICCA on solid electrolyte interphase (SEI) resistance (RSEI) and lithium stripping/plating homogeneity. In a transition metal cathode (NMC811) containing LMBs, a DR ICCA results in an up to 50% increase in lifetime due to the improved chemical composition of the cathode electrolyte interphase (CEI). Furthermore, different impacts on electrode characteristics and cell performance were observed depending on the utilized functional additive. Since this study focuses on a largely overlooked influential factor of LMB performance, it highlights the importance of comparability and transparency in published research and the importance of taking differences between research and industrial environments into consideration in the aim of establishing and commercializing LMB cell components.

Improving the electrochemical properties and cycle life of high-voltage cathodes in lithium-ion batteries requires a deep understanding of the structural properties and failure mechanisms at the cathode electrolyte interphase (CEI). We present a study implementing an advanced Raman spectroscopy technique to specifically address the compositional features of interphase during cell operation. Our operando technique, shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS), provides a reliable platform to investigate the dynamics of the interphase structure and elucidate the compositional changes near the cathode surface. To improve the CEI properties, thiophene was introduced and investigated as an effective, high-voltage film-forming additive by largely diminishing the capacity fading triggered at high potentials in LiNi1/3Co1/3Mn1/3O2 cathodes. While the cells without thiophene show severe capacity fading, cells with an optimized concentration of thiophene exhibit a significant performance improvement. Operando SHINERS detects the presence of a stable CEI. The results suggest that the composition of the CEI is dominated by polythiophene and copolymerization products of ethylene carbonate with thiophene, which protects the electrolyte components from further decomposition. The formation mechanism of the polymeric film was modeled using quantum chemistry calculations, which shows good agreement with the experimental data.

Lithium-ion batteries (LIBs) have transformed the use of mobile electronics and storage technologies. Alongside advances in materials, an in-depth understanding of the interfacial phenomena and interphase formation mechanisms in LIBs is crucial. Interphases are widely recognized as the most important and the least understood components of LIBs and play a direct role in defining cell performance, cyclability, and safety. This article presents a review of recent developments in vibrational spectroscopy techniques of Raman, infrared, and sum-frequency generation spectroscopies to probe the fundamental aspects of interphases on the anode and cathode of LIBs. First the vibrational spectroscopy techniques and their relevant technical considerations for interphase characterization are briefly introduced. In the next step, the latest studies on the fundamental properties, composition, and structure of interphases employing vibrational spectroscopy techniques are presented. This review focuses on in situ/operando investigations; however, post-mortem studies are also discussed briefly.

Electrocatalysts often show increased conversion at nanoscale chemical or topographic surface inhomogeneities, resulting in spatially heterogeneous reactivity. Identifying reacting species locally with nanometer precision during chemical conversion is one of the biggest quests in electrochemical surface science to advance (electro)catalysis and related fields. Here, we demonstrate that electrochemical tip-enhanced Raman spectroscopy can be used for combined topography and reactivity imaging of electro-active surface sites under reaction conditions. We map the electrochemical oxidation of Au nanodefects, a showcase energy conversion and corrosion reaction, with a chemical spatial sensitivity of about 10 nm. The results indicate the reversible, concurrent formation of spatially separated Au2O3 and Au2O species at defect-terrace and protrusion sites on the defect, respectively. Active-site chemical nano-imaging under realistic working conditions is expected to be pivotal in a broad range of disciplines where quasi-atomistic reactivity understanding could enable strategic engineering of active sites to rationally tune (electro)chemical device properties., Identifying reacting species locally with nanometer precision is a major challenge in electrochemical surface science. Using operando Raman nanoscopy, authors image the reversible, concurrent formation of nanometer-spatially separated Au2O3 and Au2O species during Au nanodefect oxidation.

For decades intense research efforts have been aimed at increasing energy densities with new rechargeable lithium battery (RLB) designs to meet the anticipated increasing energy storage demands. These efforts have yielded much higher capacities with novel materials. However, the theoretical capacity of an RLB cell is seeded in the structure of the electrode, while its practical capacity, performance, cycle life, and safety are deep-rooted in the side reactions at the interphase between electrode and electrolyte (interphase is the phase at the electrode-electrolyte interface) 1,2. Interphases are essential for the operation of the cells and have been widely recognized as the "most important and the least understood" components of RLBs3. While their characteristics determine their performance, they are not part of the design of RLBs, but only form during the cell operation on the anodes and cathodes. They constitute passivation layers with mixed chemistries due to the electrolytes' electrochemical stability window (ESW) being smaller than the operating potential of RLBs. Although interphase formation is of functional importance, its formation imposes a heavy price on the cell's performance. Formation of the interphase consumes the electrolyte and active lithium stored in the cathode and causes a dramatic capacity loss, especially in the initial charge/discharge cycles. Also, the presence of the interphase introduces a high level of impedance to the cell, which interrupts the fast and constant flow of Li-ion between the anode and cathode. Last but not least, interphase is an active and complex medium that changes its chemical composition and transport properties during charge/discharge cycling and storing conditions. This results in a constant evolution of the interphase and capacity fading, which is more prominent in the high cell voltage applications. Achieving high cell voltage by increasing the cut-off voltage of LiNi x Co y Mn1−x−y O2 cathode (NMC) materials to 4.5 V is an effective way to enhance the energy density of RLBs4. However, a high level of parasitic and decomposition reactions result in severe capacity fading of the battery cell5. Many efforts have been made to improve the properties of the cathode interphase at high cut-off voltage by incorporating different strategies. The in vivo approach is one of the more successful attempts to design the cathode interphase by incorporating film-forming additives in electrolytes to suppress parasite reactions at the electrode-electrolyte interface6-8. In an ideal case, this film should be stable with cycling and have excellent conductivity for Li+ ions and low electronic conductivity9. Thiophene-based molecules are investigated as effective film-forming on NMC at high cut-off voltages of 4.5 V vs. Li/Li+. Electrochemical investigations show that thiophene oxidizes before carbonate-based electrolytes and forms a stable interphase with high conductivity for Li-ion. Also, the electrochemical performance of the cell is enhanced significantly in the presence of thiophene additive with capacity retention of 95% after 100 cycles (75% capacity retention of the benchmark system). To reveal the underlying mechanisms of the interphase formation and thiophene working principle on the surface of NMC cathode, we performed operando near-field Raman spectroscopy. The Raman and electrochemistry results indicate that a poly-thiophene film is formed that covers the surface of the cathode active materials uniformly, protecting further oxidation of the electrolyte and preventing transition metal dissolution and decomposition of the active cathode materials. (1) Freunberger SA Nature Chemistry 2019, 11, 761. (2) Yang Y, Yan C, Huang JQ Acta Physico-Chimica Sinica 2021, 37. (3) Winter M Zeitschrift Fur Physikalische Chemie-International Journal of Research in Physical Chemistry & Chemical Physics 2009, 223, 1395. (4) Fergus JW Journal of Power Sources 2010, 195, 939. (5) Yan GC, Li XH, Wang ZX, Guo HJ, Wang C Journal of Power Sources 2014, 248, 1306. (6) Zhang L, Zhang ZC, Wu HM, Amine K Energy & Environmental Science 2011, 4, 2858. (7) Liu QY, Yang GJ, Li SW, Zhang SM, Chen RJ, Wang ZX, Chen LQ Acs Applied Materials & Interfaces 2021, 13, 21459. (8) Zhu XB, Schulli T, Wang LH Chemical Research in Chinese Universities 2020, 36, 24. (9) Xu K Chemical Reviews 2014, 114, 11503.

Fast charge/discharge cycles are necessary for supercapacitors applied in vehicles including, buses, cars and elevators. Nanocomposites of graphene oxide with lanthanide oxides show better supercapacitive performance in comparison to any of them alone. Herein, Eu2O3 nanorods (EuNRs) were prepared through the hydrothermal method and anchored onto the surface of reduced graphene oxide (RGO) by utilizing a sonochemical procedure (in an ultrasonic bath) through a self-assembly methodology. The morphologies of EuNRs and EuNR-RGO were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and IR spectroscopy. Then, we used EuNRs and EuNR-RGO as electrode materials to investigate their supercapacitive behavior using cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy techniques. In a 3.0 M KCl electrolyte and with a scan rate of 2 mV s−1, EuNR-RGO exhibited a specific capacity of 403 F g−1. Galvanostatic charge–discharge experiments demonstrated a specific capacity of 345.9 F g−1 at a current density of 2 A g−1. The synergy between RGO's flexibility and EuNR's high charge mobility caused these noticeable properties.

Providing a chemical control over charge transport through molecular junctions is vital to developing sensing applications at the single-molecule scale. Quantum-interference effects that affect the charge transport through molecules offer a unique chance to enhance the chemical control. Here, we investigate how interference effects can be harnessed to optimize the response of single molecule dithienoborepin (DTB) junctions to the specific coordination of a fluoride ion in solution. The single-molecule conductance of two DTB isomers is measured using scanning tunneling microscopy break-junction (STM-BJ) before and after fluoride ion exposure. We find a significant change of conductance before and after the capture of a fluoride ion, the magnitude of which depends on the position of the boron atom in the molecular structure. This single-molecule sensor exhibits switching ratios of up to four orders of magnitudes, suggesting that the boron-fluoride coordination can lead to quantum-interference effects. This is confirmed by a quantum chemical characterization, pointing toward a cross-conjugated path through the molecular structure as the origin of the effect.

The presence of heavy metal ions such as copper in the human body at certain concentrations and specific conditions can lead to the development of different diseases. The currently available analytical detection methods remain expensive, time-consuming, and often require sample pre-treatment. The development of specific and quantitative, easy-in-operation, and cost-effective devices, capable of monitoring the level of Cu2+ ions in environmental and physiological media, is necessary. We use silicon nanoribbon (SiNR) ion-sensitive field effect transistor (ISFET) devices modified with a Gly–Gly–His peptide for the detection of copper ions in a large concentration range. The specific binding of copper ions causes a conformational change of the ligand, and a deprotonation of secondary amine groups. By performing differential measurements, we gain a deeper insight into the details of the ion–ligand interaction. We highlight in particular the importance of considering non-specific interactions to explain the sensors’ response.

We studied charge transport through core-substituted naphthalenediimide (NDI) single-molecule junctions using the electrochemical STM-based break-junction technique in combination with DFT calculations. Conductance switching among three well-defined states was demonstrated by electrochemically controlling the redox state of the pendent diimide unit of the molecule in an ionic liquid. The electrical conductances of the dianion and neutral states differ by more than one order of magnitude. The potential-dependence of the charge-transport characteristics of the NDI molecules was confirmed by DFT calculations, which account for electrochemical double-layer effects on the conductance of the NDI junctions. This study suggests that integration of a pendant redox unit with strong coupling to a molecular backbone enables the tuning of charge transport through single-molecule devices by controlling their redox states.

Tuning charge transport at the single-molecule level plays a crucial role in the construction of molecular electronic devices. Introduced herein is a promising and operationally simple approach to tune two distinct charge-transport pathways through a cruciform molecule. Upon in situ cleavage of triisopropylsilyl groups, complete conversion from one junction type to another is achieved with a conductance increase by more than one order of magnitude, and it is consistent with predictions from ab initio transport calculations. Although molecules are well known to conduct through different orbitals (either HOMO or LUMO), the present study represents the first experimental realization of switching between HOMO- and LUMO-dominated transport within the same molecule.

Sol-gel based solid-phase microextraction fibers supported by a stainless steel wire were fabricated and employed for GC-MS determination of oxadiargyl in real samples. The fibers were based on four compounds with different polarity: polar and non-polar (end-capped) poly(dimethylsiloxane) (PDMS), polyethylene glycol (PEG), and poly(ethylene-propyleneglycol)-monobutyl ether (UCON). For this purpose, the surface of the stainless steel was initially modified by (3-mercaptopropyl) trimethoxysilane. The results of the modification procedure were evaluated by cyclic voltammetry and energy dispersive X-ray (EDX) spectroscopy. After the modification, four different sol-gel based SPME fibers with different values of polarity, polar and non-polar PDMS, PEG, and UCON have been prepared and investigated. They are supposed to be employed to determinate oxadiargyl in agricultural and environmental samples prior to gas chromatography-mass spectrometry analysis. Most important parameters that affect the extraction efficiency were also optimized. Under optimized conditions, the proposed method was found to be linear for the concentrations ranging from 100 ng L(-1) to 2 mg L(-1) with R(2)=0.997. Limit of detection (LOD) of 40 ng L(-1) and relative standard deviation of less than 10% were obtained. Relative recovery in environmental and agricultural samples was in the range of 73-96%.

We report an electrochemical gating approach with ∼100% efficiency to tune the conductance of single-molecule 4,4'-bipyridine junctions using scanning-tunnelling-microscopy break junction technique. Density functional theory calculation suggests that electrochemical gating aligns molecular frontier orbitals relative to the electrode Fermi-level, switching the molecule from an off resonance state to "partial" resonance.

The understanding of the charge transport through single molecule junctions is a prerequisite for the design and building of electronic circuits based on single molecule junctions. However, reliable and robust formation of such junctions is a challenging task to achieve. In this topical review, we present a systematic investigation of the anchoring group effect on single molecule junction conductance by employing two complementary techniques, namely scanning tunneling microscopy break junction (STM-BJ) and mechanically controllable break junction (MCBJ) techniques, based on the studies published in the literature and important results from our own work. We compared conductance studies for conventional anchoring groups described earlier with the molecular junctions formed through π-interactions with the electrode surface (Au, Pt, Ag) and we also summarized recent developments in the formation of highly conducting covalent Au-C σ-bonds using oligophenyleneethynylene (OPE) and an alkane molecular backbone. Specifically, we focus on the electron transport properties of diaryloligoyne, oligophenyleneethynylene (OPE) and/or alkane molecular junctions composed of several traditional anchoring groups, (dihydrobenzo[b]thiophene (BT), 5-benzothienyl analogue (BTh), thiol (SH), pyridyl (PY), amine (NH2), cyano (CN), methyl sulphide (SMe), nitro (NO2)) and other anchoring groups at the solid/liquid interface. The qualitative and quantitative comparison of the results obtained with different anchoring groups reveals structural and mechanistic details of the different types of single molecular junctions. The results reported in this prospective may serve as a guideline for the design and synthesis of molecular systems to be used in molecule-based electronic devices.

Charge transport by tunnelling is one of the most ubiquitous elementary processes in nature. Small structural changes in a molecular junction can lead to significant difference in the single-molecule electronic properties, offering a tremendous opportunity to examine a reaction on the single-molecule scale by monitoring the conductance changes. Here, we explore the potential of the single-molecule break junction technique in the detection of photo-thermal reaction processes of a photochromic dihydroazulene/vinylheptafulvene system. Statistical analysis of the break junction experiments provides a quantitative approach for probing the reaction kinetics and reversibility, including the occurrence of isomerization during the reaction. The product ratios observed when switching the system in the junction does not follow those observed in solution studies (both experiment and theory), suggesting that the junction environment was perturbing the process significantly. This study opens the possibility of using nano-structured environments like molecular junctions to tailor product ratios in chemical reactions., The conductance across single-molecule junctions is highly dependent on the electronic properties of the molecule in question. Here the authors use this fact to monitor a photo-thermal reaction by analysing break junction data, and observe significant differences compared to solution state behaviour.

The ancillary ligands 4′‐(4‐pyridyl)‐2,2′:6′,2′′‐terpyridine and 4′‐(2,3‐dihydrobenzo[b]thiophene)‐2,2′‐6′,2“‐terpyridine were used to synthesize two series of mono‐ and dinuclear ruthenium complexes differing in their lengths and anchoring groups. The electrochemical and single‐molecular conductance properties of these two series of ruthenium complexes were studied experimentally by means of cyclic voltammetry and the scanning tunneling microscopy‐break junction technique (STM‐BJ) and theoretically by means of density functional theory (DFT). Cyclic voltammetry data showed clear redox peaks corresponding to both the metal‐ and ligand‐related redox reactions. Single‐molecular conductance demonstrated an exponential decay of the molecular conductance with the increase in molecular length for both the series of ruthenium complexes, with decay constants of βPY=2.07±0.1 nm−1 and βBT=2.16±0.1 nm−1, respectively. The contact resistance of complexes with 2,3‐dihydrobenzo[b]thiophene (BT) anchoring groups is found to be smaller than the contact resistance of ruthenium complexes with pyridine (PY) anchors. DFT calculations support the experimental results and provided additional information on the electronic structure and charge transport properties in those metal|ruthenium complex|metal junctions., We acknowledge the financial support from the Swiss National Science Foundation (Grant No. 200020‐144471); SCCER Heat and Electricity storage; M.H. acknowledges the financial support from the Institute of Science and Engineering at Chuo University. H.O. is grateful to Tokuyama Science Foundation. C.J.L. and O.A.A. acknowledge financial support from the UK EPSRC (grant no. EP/M014452/1 and EP/N017188/1), the European Commission (EC) FP7 ITN “MOLESCO” (project no. 606728), and the Ministry of Higher Education and Scientific Research of Iraq. V.M.G.‐S. and J.F. thank the Spanish MICINN for funding (Grant No. FIS2012‐34858). V.M.G.‐S. also thanks the Spanish MICINN for a Ramón y Cajal Fellowship (RYC‐2010‐06053).

Single molecule charge transport characteristics of buckminsterfullerene-capped symmetric fluorene-based dumbbell-type compound 1 were investigated by scanning tunneling microscopy break junction (STM-BJ), current sensing atomic force microscopy break junction (CS-AFM-BJ), and mechanically controlled break junction (MCBJ) techniques, under ambient conditions. We also show that compound 1 is able to form highly organized defect-free surface adlayers, allowing the molecules on the surface to be addressed specifically. Two distinct single molecule conductance states (called high G(H)(1) and low G(L)(1)) were observed, depending on the pressure exerted by the probe on the junction, thus allowing molecule 1 to function as a mechanically driven molecular switch. These two distinct conductance states were attributed to the electron tunneling through the buckminsterfullerene anchoring group and fully extended molecule 1, respectively. The assignment of conductance features to these configurations was further confirmed by control experiments with asymmetrically designed buckminsterfullerene derivative 2 as well as pristine buckminsterfullerene 3, both lacking the G(L) feature.

Controlling charge transport through a single molecule connected to metallic electrodes remains one of the most fundamental challenges of nanoelectronics. Here we use electrochemical gating to reversibly tune the conductance of two different organic molecules, both containing anthraquinone (AQ) centers, over >1 order of magnitude. For electrode potentials outside the redox-active region, the effect of the gate is simply to shift the molecular energy levels relative to the metal Fermi level. At the redox potential, the conductance changes abruptly as the AQ unit is oxidized/reduced with an accompanying change in the conjugation pattern between linear and cross conjugation. The most significant change in conductance is observed when the electron pathway connecting the two electrodes is via the AQ unit. This is consistent with the expected occurrence of destructive quantum interference in that case. The experimental results are supported by an excellent agreement with ab initio transport calculations.

The synthesis and characterisation is described of six diaryltetrayne derivatives [Ar-(C[TRIPLE BOND]C)4-Ar] with Ar=4-NO2-C6H4- (NO24), 4-NH(Me)C6H4- (NHMe4), 4-NMe2C6H4- (NMe24), 4-NH2-(2,6-dimethyl)C6H4- (DMeNH24), 5-indolyl (IN4) and 5-benzothienyl (BTh4). X-ray molecular structures are reported for NO24, NHMe4, DMeNH24, IN4 and BTh4. The stability of the tetraynes has been assessed under ambient laboratory conditions (20 °C, daylight and in air): NO24 and BTh4 are stable for at least six months without observable decomposition, whereas NHMe4, NMe24, DMeNH24 and IN4 decompose within a few hours or days. The derivative DMeNH24, with ortho-methyl groups partially shielding the tetrayne backbone, is considerably more stable than the parent compound with Ar=4-NH2C6H4 (NH24). The ability of the stable tetraynes to anchor in Au|molecule|Au junctions is reported. Scanning-tunnelling-microscopy break junction (STM-BJ) and mechanically controllable break junction (MCBJ) techniques are employed to investigate single-molecule conductance characteristics.

The synthesis is reported of a new series of oligo(aryleneethynylene) (OAE) derivatives of up to ca. 6 nm in molecular length (OAE9) using iterative Pd-mediated Sonogashira cross-coupling methodology. The oligo-p-phenyleneethynylene cores of the molecular wires are functionalized at both termini with pyridyl units for attachment to gold leads. The molecular structures determined by single-crystal X-ray analysis are reported for OAE4, OAE5, OAE7, and OAE8a. The charge transport characteristics of derivatives OAE3–OAE9 in single-molecular junctions have been studied using the mechanically controlled break junction technique. The data demonstrate that the junction conductance decreases with increasing molecular length. A transition from coherent transport via tunneling to a hopping mechanism is found for OAE wires longer than ca. 3 nm.

A method based on solid-phase microextraction (SPME) followed by on-fiber derivatization and gas chromatography–mass spectrometry detection (GC–MS) for determination of phenol in air was developed. Three different types of SPME fibers, polar and non-polar poly(dimethylsiloxane) (PDMS) and polyethylene glycol (PEG) were synthesized using sol–gel technology and their feasibility to the sampling of phenol were investigated. Different derivatization reagents for post on-fiber derivatization of phenol were studied. Important parameters influencing the extraction and derivatization process such as type of fiber coating, type and volume of derivatizing reagent, derivatization time and temperature, extraction time, and desorption conditions were investigated and optimized. The developed method is rapid, simple, easy and inexpensive and offers high sensitivity and reproducibility. Under the optimized conditions, the detection limit of the method was 5 ng L −1 using selected ion monitoring (SIM) mode. The inter-day and intra-day precisions of the developed method under optimized conditions were below 10%, and the method shows linearity in the range of 20 ng L −1 to 500 μg L −1 with the correlation coefficient of >0.99. The optimized method was applied to the sampling of phenol from some biologics production areas. The compared results obtained using current and standard methods were shown to be satisfactory.

A novel solid phase microextraction (SPME) fiber was fabricated by electrospinning method in which a polymeric solution was converted to nanofibers using high voltages. A thin stainless steel wire was coated by the network of polymeric nanofibers. The polymeric nanofiber coating on the wire was mechanically stable due to the fine and continuous nanofibers formation around the wire with a three dimensional structure. Polyamide (nylon 6), due to its suitable characteristics was used to prepare the unbreakable SPME nanofiber. The scanning electron microscopy (SEM) images of this new coating showed a diameter range of 100–200 nm for polyamide nanofibers with a homogeneous and porous surface structure. The extraction efficiency of new coating was investigated for headspace solid-phase microextraction (HS-SPME) of some environmentally important chlorophenols from aqueous samples followed by gas chromatography–mass spectrometry (GC–MS) analysis. Effect of different parameters influencing the extraction efficiency including extraction temperature, extraction time, ionic strength and polyamide amount were investigated and optimized. In order to improve the chromatographic behavior of phenolic compounds, all the analytes were derivatized prior to the extraction process using basic acetic anhydride. The detection limits of the method under optimized conditions were in the range of 2–10 ng L −1 . The relative standard deviations (RSD) ( n = 3 ) at the concentration level of 1.7–6.7 ng mL −1 were obtained between 1 and 7.4%. The calibration curves of chlorophenols showed linearity in the range of 27–1330 ng L −1 for phenol and monochlorophenols and 7–1000 ng L −1 for dichloro and trichlorophenols. Also, the proposed method was successfully applied to the extraction of phenol and chlorophenols from real water samples and relative recoveries were between 84 and 98% for all the selected analytes except for 2,4,6 tricholophenol which was between 72 and 74%.

Interface engineering to attain a uniform and compact self-assembled monolayer at atomically flat surfaces plays a crucial role in the bottom-up fabrication of organic molecular devices. Here we report a promising and operationally simple approach for modification/functionalization not only at ultraflat single-crystal metal surfaces, M(111) (M=Au, Pt, Pd, Rh and Ir) but also at the highly oriented pyrolytic graphite surface, upon efficient in situ cleavage of trimethylsilyl end groups of the molecules. The obtained self-assembled monolayers are ultrastable within a wide potential window. The carbon–surface bonding on various substrates is confirmed by shell-isolated nanoparticle-enhanced Raman spectroscopy. Application of this strategy in tuning surface wettability is also demonstrated. The most valuable finding is that a combination of the desilylation with the click chemistry represents an efficient method for covalent and tailor-made functionalization of diverse surfaces., Formation of stable and uniform self-assembled monolayers on surfaces is a prerequisite for bottom-up fabrication of many organic molecular devices. Here, the authors present a fabrication approach based on desilylation chemistry for modification and functionalization on various metal and carbon surfaces.

A quantum circuit rule for combining quantum interference effects in the conductive properties of oligo(phenyleneethynylene) (OPE)-type molecules possessing three aromatic rings was investigated both experimentally and theoretically. Molecules were of the type X-Y-X, where X represents pyridyl anchors with para (p), meta (m) or ortho (o) connectivities and Y represents a phenyl ring with p and m connectivities. The conductances GXmX (GXpX) of molecules of the form X-m-X (X-p-X), with meta (para) connections in the central ring, were predominantly lower (higher), irrespective of the meta, para or ortho nature of the anchor groups X, demonstrating that conductance is dominated by the nature of quantum interference in the central ring Y. The single-molecule conductances were found to satisfy the quantum circuit rule Gppp/Gpmp=Gmpm/Gmmm. This demonstrates that the contribution to the conductance from the central ring is independent of the para versus meta nature of the anchor groups.

Heteroatom substitution into the cores of alternant, aromatic hydrocarbons containing only even-membered rings is attracting increasing interest as a method of tuning their electrical conductance. Here, the effect of heteroatom substitution into molecular cores of non-alternant hydrocarbons, containing odd-membered rings, is examined. Benzodichalcogenophene (BDC) compounds are rigid, planar pi-conjugated structures, with molecular cores containing five-membered rings fused to a six-membered aryl ring. To probe the sensitivity or resilience of constructive quantum interference (CQI) in these non-bipartite molecular cores, two C-2-symmetric molecules (I and II) and one asymmetric molecule (III) were investigated. I (II) contains S (O) heteroatoms in each of the five-membered rings, while III contains an S in one five-membered ring and an O in the other. Differences in their conductances arise primarily from the longer S-C and shorter O-C bond lengths compared with the C-C bond and the associated changes in their resonance integrals. Although the conductance of III is significantly lower than the conductances of the others, CQI was found to be resilient and persist in all molecules.