bluuebunny/crossref_metadata_2025 huggingface dataset:
(Invited) Synthesis of the Elusive Dimetallofullerenes
Authors: Liu Fupin , Spree Lukas , Popov Alexey A.
Published: February 2020

The metal-metal (M-M) bonding in dimetallofullerenes presents the peculiar electronic structures as well as the chemical and physical properties.[1-2] For Y and medium-size lanthanides, computations by Shinohara et al. showed that M2@C80 has one unpaired electron occupying the M–M bonding molecular orbitals, and the other electron is delocalized over the carbon cage.[3] Such molecules are elusive radicals. Recently, we have succeeded in the capture of the elusive M2@C80 (M=Y, Gd, Tb, Dy, Ho, and Er) as benzyl derivatives.[4] In this contribution, the synthesis and structural characterizations of these M2@C80–CH2Ph will be discussed.

[1] A. A. Popov, S. Yang, L. Dunsch, Chem.
Rev.
2013, 113, 5989-6113.

[2] A. A. Popov, S. M. Avdoshenko, A. M. Pendas, L. Dunsch, Chem. Commun.
2012, 48, 8031-8050.

[3] Z. Wang, R. Kitaura, H. Shinohara, J. Phys. Chem. C
2014, 118, 13953-13958.

[4] F. Liu, D. S. Krylov, L. Spree, S. M. Avdoshenko, N. A. Samoylova, M. Rosenkranz, A. Kostanyan, T. Greber, A. U. B. Wolter, B. Büchner, A. A. Popov, Nat. Commun.
2017, 8, 16098.
(Invited) MXenes: From Fundamental Science to Emerging Applications
Authors: Kurra Narendra , Gogotsi Yury
Published: February 2020

Two-dimensional (2D) nanomaterials have been attractive candidates for a plethora of applications since the successful isolation and demonstration of intriguing electronic properties of graphene in 2004 by the Manchester group. The ‘beyond graphene’ march led to the discovery of new types of 2D materials, expanding the flatland research. MXenes, a relatively new and large family of 2D transition metal carbides, nitrides, and carbonitrides, which were discovered at Drexel in 2011 and have become popular due to their diverse chemistries and unique physicochemical properties. These materials are produced by top-down wet chemical or electrochemical extraction of interleaved ‘A’ atomic layers from the layered ternary carbide precursors (MAX phases). The resulting MXenes with surface terminations (-O, -F, -OH) impart negative surface charges, key for stable MXene dispersions in water and organic solvents which enable solution processing. More than 30 different MXenes have been experimentally synthesized, with dozens of new MXenes and their properties predicted computationally. The compositional versatility, metallic conductivity, control of surface chemistry, ordered structures versus solid solutions, etc. make MXenes diverse and suitable for a wide spectrum of applications including but not limited to energy storage, photo- and electro-catalysis, water desalination, optoelectronics, electromagnetic interference shielding, antennas, and smart textiles.

The available 2D gallery spaces, redox chemistry at the transition metal oxide-like surface with metallic conductivity, enable MXenes as potential candidate materials for high rate capacitive energy storage applications. The ability of MXenes to spontaneously intercalate a variety of cations while promoting fast charge transfer rates, endorses them for hybrid metal-ion capacitors and battery applications. The electrocatalytic property of MXenes can be tuned based on type of transition metal, amount of defects and surface functionality. Furthermore, combination of slit-like pores with electronic conductivity, qualifies MXenes as capacitive deionization (CDI) electrodes for efficient and reversible removal of ionic species/organic molecules from brackish water. Unlike most of the 2D materials produced by bottom-up routes in small quantities, pilot scale synthesis of MXenes is a promising aspect for immediate future commercialization.
(Invited) Efficient Photodetection in 2D Materials and 2D/3D Heterostructures
Authors: Lemme Max Christian
Published: February 2020

This talk will focus on efficient and broadband photodetectors made from heterostructures of two-dimensional materials and conventional semiconductors [1], [2]. Graphene/silicon photodiodes show particularly high response, when the graphene is partly separated from the silicon by an oxide [3]. This effect is utilized in a specific contact pattern scheme that includes both regions of graphene/silicon Schottky diodes and graphene/silicon oxide/silicon (MOS) structures to enable highly sensitive G/Si photodiodes [4]. With this design, we achieve an external quantum efficiency (EQE) of > 80% for wavelengths between 380 and 930 nm. The maximum EQE of 98% is observed at 850 nm, where the responsivity also peaks to 635 mA/W. This high value is attributed to the highly effective collection of charge carriers in the MOS parts of the diodes and outperforms conventional Si p-n photodiodes. Based on these results, we define the ‘true’ active area in G/Si photodiodes.

The transition metal dichalcogenide (TMD) molybdenum disulfide (MoS2) is an n-type semiconducting 2D material with a direct band gap of ~1.8 eV in single layer form, while bulk MoS2 has an additional indirect band gap of ~1.3 eV. MoS2/Si heterostructure diodes made with multilayer, CVD grown MoS2 yield a maximum spectral response of 8.6 mA/W [1]. Furthermore, MoS2-based photodiodes on flexible substrates will be discussed. Finally, recent results on the TMD platinum diselenide (PtSe2) will be presented. Made from thermally converted platinum at low temperatures [5], [6], PtSe2 is semimetallic and is an efficient absorber in the infrared range [7].

[1] C. Yim et al., “Heterojunction Hybrid Devices from Vapor Phase Grown MoS2,” Sci. Rep., vol. 4, Jun. 2014.

[2] S. Riazimehr et al., “Spectral sensitivity of graphene/silicon heterojunction photodetectors,” Solid-State Electron., vol. 115, Part B, pp. 207–212, Jan. 2016.

[3] S. Riazimehr et al., “High Photocurrent in Gated Graphene–Silicon Hybrid Photodiodes,” ACS Photonics, vol. 4, no. 6, pp. 1506–1514, Jun. 2017.

[4] S. Riazimehr et al., “High Responsivity and Quantum Efficiency of Graphene / Silicon Photodiodes Achieved by Interdigitating Schottky and Gated Regions,” ACS Photonics, 2018.

[5] C. Yim et al., “High-Performance Hybrid Electronic Devices from Layered PtSe2 Films Grown at Low Temperature,” ACS Nano, vol. 10, no. 10, pp. 9550–9558, Oct. 2016.

[6] C. Yim et al., “Electrical devices from top-down structured platinum diselenide films,” Npj 2D Mater. Appl., vol. 2, no. 1, p. 5, Feb. 2018.

[7] C. Yim et al., “Wide Spectral Photoresponse of Layered Platinum Diselenide-Based Photodiodes,” Nano Lett., vol. 18, no. 3, pp. 1794–1800, Mar. 2018.
(Invited) Large Area Ion Sensitive Graphene Field Effect Transistors for Potassium, Sodium and Chlorine Sensing
Authors: Fakih Ibrahim , Mahvash Farzaneh , Ghaddab Boutheina , Centeno Alba , Zurutuza Amaia , Siaj Mohamed , Szkopek Thomas
Published: February 2020

We review our work on large-area graphene based ion sensitive field effect transistors (ISFETs), employing metal oxide layers or ionophore based membranes. Unlike traditional silicon based ISFETs, our work is focused on macroscopic graphene devices fabricated using chemical vapour deposition methods. Large-area graphene ISFETs benefit from the combination of high mobility charge transport, reduced low-frequency noise with increasing transistor channel area, and facile integration with ion sensitive layers. Graphene ISFETs with an active area of approximately 1cm x 1cm are characterized by an rms current noise as low as 5 ~ nA in a 60 Hz bandwidth, field effect mobilities up to 5000 cm2 V-1 s-1 and quantum capacitance limited coupling between graphene channel and the solid/electrolyte interface. We have demonstrated graphene ISFETs selectively sensitive to H+, K+, Na+ and Cl-. In the case of H+ sensing, metal oxides such as Ta2O5 and Al2O3 deposited by atomic layer deposition can be used to achieve Nernstian limited sensitivity with a 0.1 mpH resolution. Ion sensitive membranes based on ionophores can be used for selective sensing of other ionic species. For example, in the specific case of the K+, real-time sensing was achieved using potassium ionophore III with a detection limit of 10-9 M [K+], equivalent to 39~ng/L, and a resolution of 1.5×10-3 log[K+]. Spiking experiments reveal good reversibility and stability. The cross-sensitivity has been measured to be: 2.5 mV/decade for Na+, 4.2 mV/decade for Ca2+, 1.5 mV/decade for Mg2+ and 9.0 mV/decade for NH4
+. Graphene ISFETs are sufficiently robust to measure the K+ content of common beverages and blood samples. We will conclude our talk with a discussion of open questions concerning graphene ISFET performance and their potential applications.
(Invited) Controlling and Tailoring the Electronic Properties of Chemically Reactive 2D Materials
Authors: Hersam Mark C.
Published: February 2020

Following the success of ambient-stable two-dimensional (2D) materials such as graphene and hexagonal boron nitride (hBN), new classes of chemically reactive layered solids are being explored since their unique electronic and optical properties hold significant promise for improved device performance [1]. For example, chemically reactive 2D semiconductors such as black phosphorus (BP) and indium selenide (InSe) have shown significantly enhanced field-effect mobilities under controlled conditions that minimize ambient degradation [2]. In addition, 2D boron (i.e., borophene) is an anisotropic metal with a diverse range of theoretically predicted phenomena including confined plasmons, charge density waves, and superconductivity [3], although its high chemical reactivity has limited experimental studies to inert ultrahigh vacuum conditions [4-6]. Therefore, to fully study and exploit the vast majority of 2D materials, methods for mitigating or exploiting their relatively high chemical reactivity are required [7]. This talk will thus explore recent efforts to control and tailor the electronic properties of chemically reactive 2D materials [8]. In particular, covalent organic functionalization of black phosphorus minimizes ambient degradation, provides charge transfer doping, and enhances field-effect transistor mobility and on/off ratio [9]. In contrast, noncovalent organic functionalization of borophene leads to the spontaneous formation of electronically abrupt lateral organic-borophene heterostructures [10]. Finally, atomic layer deposition (ALD) encapsulation schemes will be discussed that impart ambient stability to high-performance black phosphorus infrared optical emitters [11] and InSe photodetectors [12].

[1] A. J. Mannix, et al., Nature Reviews Chemistry, 1, 0014 (2017).

[2] D. Jariwala, et al., Nature Materials, 16, 170 (2017).

[3] A. J. Mannix, et al., Nature Nanotechnology, 13, 444 (2018).

[4] A. J. Mannix, et al., Science, 350, 1513 (2015).

[5] G. P. Campbell, et al., Nano Letters, 18, 2816 (2018).

[6] X. Liu, et al., Nature Materials, 17, 783 (2018).

[7] C. R. Ryder, et al., ACS Nano, 10, 3900 (2016).

[8] X. Liu, et al., Advanced Materials, 30, 1801586 (2018).

[9] C. R. Ryder, et al., Nature Chemistry, 8, 597 (2016).

[10] X. Liu, et al., Science Advances, 3, e1602356 (2017).

[11] C. Husko, et al., Nano Letters, 18, 6515 (2018).

[12] S. A. Wells, et al., Nano Letters, DOI: 10.1021/acs.nanolett.8b03689 (2018).
(Invited) Perovskite Single Crystals with Free-Hole Trapping Centers for Photodetector and Solar Cell Applications
Authors: Mohammed Omar
Published: February 2020

The methylammonium lead iodide (MAPbI3) single crystals show extremely low trap-state density, high charge carrier diffusion length, long radiative carrier lifetime and high charge carrier mobility, making them outstanding candidates for a variety of potential applications including solar cells and photodetectors. However, these single crystals whatever the structure compositions still severely suffer from the presence of impurity traces such as triiodide that formed during their growth at high temperature. These traces can act as electron and hole quenching centers on the surface and at the device interface, hindering the further development of the performance of the solar cells and photodetectors based on these crystals. They also suffer from ions migrauion, vacancies, interstitials, and surface resturcturing and degradation especially under environmental conditions. Here, we will first show tremendous impact of the presence of excess triiodide on the charge carrier lifetime, carrier mobility and the performance of their solar cell and photodetector devices. We will also show the significant impact of the structure of organic cations on halogen migration, vacancies, and interstitials, carrier lifetimes as well as surface degradation of these single crystal perovskites using a combination of experimental and theoretical investigations. Finally, the unprecedented photo-response and photo-conversion efficiency after the chemical treatment of these single crystals will be presented and discussed.
(Invited) Effect of Particle Size on Photocatalytic Reaction Kinetics Including Multielectron-Transfer Processes
Authors: Ohtani Bunsho , Takashima Mai
Published: February 2020

Oxidation of water into molecular oxygen (O2 + 4H+ + 4e– → 2H2O) must be the largest-scale chemical reaction occurring on the earth as a part of photosynthesis by plants, and the corresponding backward half-cell reaction, reduction of oxygen into water (O2 + 4H+ + 4e– → 2H2O) might proceed in the same scale by the activity of plants and animals to get energy by combustion of chemicals keeping the concentration of oxygen on the earth. It is well known that the forward and backward reactions are counter oxidation and reduction reactions, respectively, of photocatalytic water splitting/carbon-dioxide fixation and photocatalytic decomposition of organic compounds by semiconductor particles.

Standard electrode potential (SEP) of this four electron-transfer redox (O2 + 4H+ + 4e– = 2H2O) is 1.23 V (versus SHE = standard hydrogen electrode potential (0 V) in definition). Almost all the papers reporting oxygen evolution use this SEP, while those of photocatalytic organics decomposition tend to use SEP for one-electron transfer, O2 + e– = O2•– (–0.28 V), for discussion. One of the possible reasons for such difference is that it is convenient to presume the production of superoxide anion radical which may produce "reactive oxygen species (ROS)" to decompose organic compounds. Anyway, it can be stated that those proposed number of transferred electrons seems speculative without any experimental evidence.

We have been studying light-intensity dependence (LID) of photocatalytic reaction rates using highly intense UV-LEDs with intensity maximally ca. 3 W cm-2. For oxygen evolution from aqueous titania suspensions in the presence of electron acceptors such as iodate (IO3
–) or iron(III) ions under deaerated conditions, small anatase (8 nm) and rutile (13 nm) particles show bimodal, at first second and then first order, LID in the lower and middle intensity range while large anatase and rutile particles show simple first-order LID in the whole intensity range. This is attributable to two-electron (positive hole) transfer process in the initial step. An interesting feature is that forth-order LID was observed with small anatase particles at high (2.5 W cm-2) intensity to suggest shift of the kinetics to four-electron transfer process [1]. For oxygen reduction, LID analyses for the rate of oxidative decomposition of acetic acid by a bismuth tungstate photocatalyst suggested that two-electron oxygen reduction predominantly proceeds [2]. On the basis of these results, "effective particle size" defined as size of particle (or particle aggregates) in which multiple electrons (positive holes) are accumulated to induce multielectron processes is proposed. This "effective particle size" may govern the effect of size on photocatalytic reaction rates.

[1] Takeuchi, S.; Takashima, M.; Takase, M.; Ohtani, B. Chem. Lett.
2018, 47, 373-376.

[2] Hori, H.; Takashima, M.; Takase, M.; Ohtani, B. Catal. Today
2018, 313, 218-223.
(Invited) Synthesis of Multimetallic Subnano Particles Using a Dendrimer Reactor
Authors: Yamamoto Kimihisa
Published: February 2020

Dendrimers are highly branched organic macromolecules with successive layers or “generations” of branch units surrounding a central core. Organic inorganic hybrid versions have also been produced, by trapping metal ions or metal clusters within the voids of the dendrimers. Their unusual, tree-like topology endows these nanometer-sized macromolecules with a gradient in branch density from the interior to the exterior, which can be exploited to direct the transfer of charge and energy from the dendrimer periphery to its core.

We show that tinchloride, SnCl2 and FeCl3 complexes to the imines groups of a spherical polyphenylazomethine dendrimer in a stepwise fashion according to an electron gradient, with complexation in a more peripheral generation proceeding only after complexation in generations closer to the core has been completed. By attaching an electron-withdrawing group to the dendrimer core, we are able to change the complexation pattern, so that the core imines are complexed last. By further extending this strategy, it should be possible to control the number and location of metal ions incorporated into dendrimer structures, which might and uses as tailored catalysts, building blocks, or fine-controlled clusters for advanced materials.　The metal-assembly in a discrete molecule can be converted to a size-regulated metal particle with a size smaller than 1 nm as a molecular reactor. Due to the well-defined number of metal particles in the subnanometer size region, its property is much different from that of bulk or general metal nanoparticles.
Bis-Porphyrin Structural Motiff for Chirality and Molecular Sensing
Authors: Du Rui , Zhou Zhongqiang , Borovkov Victor
Published: February 2020

Bis-porphyrin structures are widely used as model systems to mimic various natural processes and have numerous practical applications in the research and technoligical fields such as polymer and nano science, light harvesting and nonlinear optics, chemical sensors and catalysis, molecular and chiral recognition, various supramolecular and chiroptical devices, chirogenesis and absolute configuration determination.

Several years ago, we have discovered that a simple ethane-bridged bis-porphyrin structural motif (M = Zn, Mg, Cu, Co, 2H), can be effectively served for different application purposes owing to the specific molecular and supramolecular functionalities. In particular, the unique functional property of this bis-porphyrin host is based upon the structural semi-flexibility of covalent linkage between two porphyrin unitsresulting in the environmentally assisted syn-anti conformational switching and tweezer formation depending upon the guest structure, which can be effectively employed in different sensing areas, such as chirogenic probes, chiral recognitions, and chemical sensors .1-13

Further developments and prospects toward new chiral and achiral bis- and multi porphyrin systems on the basis of heterometallic bis- and multi-porphyrin structures will be discussed.

Borovkov, Symmetry
2014, 6, 256.

Borovkov, Symmetry
2010, 2, 184.

Borovkov, Y. Inoue, Eur. J. Org. Chem.
2009, 189.

A. Hembury, V. V. Borovkov, Y. Inoue, Chem. Rev.
2008, 108, 1.

V. Borovkov, Y. Inoue, Top. Curr. Chem.
2006, 265, 89.

V. Borovkov, G. A. Hembury, Y. Inoue, Acc. Chem. Res.
2004, 37, 449.

Giancane, V. Borovkov, Y. Inoue, L. Valli, J. Colloid Interface Sci.
2012, 385, 282.

Giancane, V. Borovkov, Y. Inoue, S. Conoci, L. Valli,Soft Matter
2013, 9, 2302.

Bettini, E. Maglie, R. Pagano, V. Borovkov, Y. Inoue, L. Valli, G. Giancane, Beilstein J. Nanotechnol.
2015, 6, 2154.

Colombelli, M.G. Manera, V. Borovkov, G. Giancane, L. Valli, R. Rella, Sensor Actuat. B-Chem.
2017, 246, 1039.

Buccolieri, D. Manno, A. Serra, A. Santino, M. Hasan, V. Borovkov, G. Giancane,Sensor Actuat. B-Chem.
2018, 257, 685.

Buccolieri, M. Hasan, S. Bettini, V. Bonfrate, L. Salvatore, A.Santino, V. Borovkov, G.,Giancane, Anal. Chem.
2018, 90, 6952.

Bettini, R. Pagano, V. Borovkov, G. Giancane , L. Valli, J. Colloid Interface Sci.
2019, 533, 762-770.
Synthesis of Dithiophene-Monobenzo-Tetra(4-isopropylphenyl)Porphyrin
Authors: Stewart Courtney
Published: February 2020

Porphyrins have been recognized as promising leads for harvesting applications due to their strong absorption and ability for extended π-conjugation. There have been several porphyrin-based compounds that have been developed in the hopes of increasing the efficiency of these applications. For instance, thiophene derivatives have been studied with porphyrins due to their use as a π-linker, facile functionalization with both electron withdrawing and electron donating groups, and capability to redshift absorption spectra of the porphyrin. In this report, the synthesis, MALDI, and crystal structure of a new β-extended disubstituted-vinylthiophene-monobenzo-tetra(4-isopropylphenyl)porphyrin is discussed.

Figure 1
Rigid and Flexible Bis-Porphyrinic Tweezers: Efficient Molecular Recognition of Bidentate Bases.
Authors: Rein Regis , Solladie Nathalie
Published: February 2020

Increasing efforts are devoted to the synthesis of cofacial bis-porphyrinic tweezers able to complex various bidentate guests through axial coordination of the Zn(II) porphyrins by the two nitrogen atoms. Elaboration of rigid receptors appeared up to now as the ideal way to pre-organize a bis-porphyrinic cavity and increase the stability of the formed host/guest complexes. However, the choice of using rigid spacer to attach the two porphyrins together may cost a lot as far as solubility and stability are concerned. The synthetic pathways necessary to achieve the synthesis of rigid systems are frequently long and tedious. We report here the synthesis and studies of new flexible bis-porphyrinic tweezers bearing uridine as linkers and offering pre-organized cavities able to welcome bidentate guests with extremely high association constants.

As part of our studies concerning complexation of bidentate Lewis bases by bis-porphyrinic tweezers, we have synthesized two new bis-porphyrins bearing a flexible nucleosidic linker. Both uridine and 2’-deoxyuridine spacers were chosen on account of some observations we made a few years ago on the unexpected blocked conformations adopted by a pentaporphyrin consisting of four Zn(II) porphyrins attached to a central free-base porphyrin by four nucleosidic linkers. Since we observed no such blocked conformations in other flexible pentaporphyrins, we thought this might be due to the nucleosidic nature of the linkers. We thus synthesized two dimers, which differ by the attachment positions of the two porphyrins.

The ability of these two tweezers to accomodate guests was investigated through ligand binding studies carried out in dichloromethane with DABCO as bidentate base. The complexation of DABCO by these dimers was monitored by UV-visible spectrophotometric titration in CH2Cl2. The binding constants between these two tweezers and DABCO were calculated from UV-visible spectroscopic data. These association constants are unexpectedly increased by more than one order of magnitude as compared to the association constants of the same bidentate ligand with a reference Zn(II) mono-porphyrin. This enhanced stability of the complexes may be ascribed to a pre-organization of the bis-porphyrinic tweezers forming a cavity, and provides convincing evidence that the bidentate base is inserted into the cavity of the dimers via host/guest interactions.

We demonstrated that similar association constants can be obtained with flexible tweezers bearing uridine as linker and rigid tweezers. However, the stability of these flexible complexes isn’t as convincing as for our rigid tweezers bearing a tris-anthracenic spacer since the addition of an excess of DABCO destroys all the flexible complexes.

Molecular modelling of one of the flexible tweezers and its 1/1 complex with DABCO is represented below, as well as our rigid tweezers bearing a tris-anthracenic spacer.

Acknowledgements

This work was supported by the CNRS and the French Ministry of Research.

Figure 1
Gas Phase Synthesis and Deposition of Directly Fused Porphyrin Tapes: Reaction Mechanism and Central Metal Ion Effect.
Authors: Bengasi Giuseppe , Baba Kamal , Back Oliver , De Castro Olivier , Frache Gilles , Heinze Katja , Boscher Nicolas D.
Published: February 2020

The formation of directly fused porphyrin tapes attracted the interest of the scientific community because of their electronic and optical properties such as extremely low bandgap, NIR and two photon absorption. The synthesis of these compounds is tedious because of their low solubility and require the introduction of solubilizing substituents adding further synthetic efforts.[1] Moreover, these materials are hard to process and integrate into device while the solubilizing substituents hinder the π­-π interactions affecting the properties of the resulting materials.[1],[2] These drawbacks were circumvented with the oxidative Chemical Vapour Deposition (oCVD) of phenyl meso-substituted porphyrins, which allowed to achieve in a single step the synthesis, deposition and doping of polymeric fused porphyrins tapes thin films from commercially available chemicals.[2] Our approach allows the deposition of patterned films and is compatible with sensitive substrates such as paper or polymers (Figure 1a). Using Ni(II) 5,15–(diphenyl) porphyrin (NiDPP), 5,10,15–(triphenyl) porphyrin (NiP3P) and 5,10,15,20–(tetraphenyl) porphyrin (NiTPP), we elucidate the reaction active sites, the side reactions (Figure 1b) and the differences to solution based approaches via high resolution mass spectrometry, UV-Vis-NIR spectroscopy, electron paramagnetic resonance (EPR) and Density Functional Theory (DFT). We also investigate the effect of the central metal ion on the direct fusion reaction of Fe(III)Cl, Co(II), Ni(II), Cu(II), Pd(II), H2 and Zn(II), 5,15–(diphenyl) porphyrins in oCVD. Furthermore, the electrical, electronic and morphological properties of the prepared thin films were thoroughly investigated by means of X-ray Photoelectron Spectroscopy (XPS), Helium Ion Microscopy (HIM) and Conductive Atomic Force Microscopy (C-AFM).

[1] T. Tanaka, A. Osuka – Conjugated porphyrin arrays: synthesis, properties and applications for functional materials – Chem Soc Rev.
2015, 44, 943.

[2] G. Bengasi, K. Baba, G. Frache, P. Gratia, K. Heinze, N. D. Boscher – Conductive Fused Porphyrin Tapes on Sensitive Substrates by a Chemical Vapor Deposition Approach – Angew. Chem. Int. Ed.
2018, DOI: 10.1002/anie.201814034.

Figure 1) a) The chemical vapour deposition reaction of NiDPP and FeCl3 yields a homogeneous and conductive coating also on sensitive and bendable substrates which evidences the suitability for modern optoelectronic devices. b) Reaction schemes for the CVD reaction of NiDPP and FeCl3 and side reactions observed during the deposition (chlorination, cyclization of the phenyl ring).

Figure 1
Molecular Design of Metal Phthalocyanines with Strong Electron-Donating Substituents for Perovskite Solar Cells
Authors: Zanotti Gloria
Published: February 2020

Perovskite solar cells have recently revolutionized the field of the emerging photovoltaic technologies, showing an impressive evolution in the last ten years jumping from an initial 3.8%1 to a 22.1%2 certified efficiency. Nonethless, there are still ongoing challenges to face in order to foresee their commercialization, some of which are related to the use of the expensive Spiro-OMeTAD as hole transport material (HTM) and to the active layer morphology, whose inhomogeneity can promote low-resistance shunting paths, loss of light absorption and perovskite degradation in the solar cells, undermining their photovoltaic performances and stability during time. Phthalocyanines are macrocyclic aromatic compounds that can potentially address both the issues: their p-type semiconducting properties make them appealing materials as hole transporters and at the state of the art, they have scored very high efficiencies3-4 in perovskite-based devices. Furthermore, they are potentially effective as surface passivants, reducing the active layer pinholes and increasing both stability and performances of the corresponding devices, because of their excellent thermal and chemical stability, hydrophobic carbon-based core and good processability within the solar cells.

With the aim of addressing both the issues individually, in this contribution we will discuss our synthetic strategies for the preparation of several metal phthalocyanines, conveniently functionalized with strong electron-donating substituents and suitable functional groups, along with our first results of their implementation in perovskite-based devices.

References:

Kojima, A.; Teshima, K.; Shirai, Y.; Miyasaka, T. Am.
Chem. Soc.
2009, 131(17), 6050-6051.

Yang, W. S.; Park, B.-W-; Jung, E. H.; Jeon, N. J.; Kim, Y. C.; Lee, D. U.; Shin, S. S.; Seo, J.; Kim, E. K.; Noh, J. H.; Seok, S. I. Science, 2017, 356, 1376-1379.

Cho, K. T.; Trukhina, O.; Roldán-Carmona, C.; Ince, M.; Gratia, P.; Grancini, G.; Gao, P.; Marszalek, T.; Pisula, W.; Reddy, P. Y.; Torres, T.; Nazeeruddin, M. K.
Energy Mater.
2017, 1601733.

Duong, T. et al., ACS Energy Lett., 2018, 3(10), 2441–2448.
Subphthalocyanine Fused Dimer and Subphthalocyanines Conjugates
Authors: Zango German , Mariñas Víctor , Fernandez-Vera Oscar , Gallego Lucia , Lavarda Giulia , Medina Diana Paola , Martínez-Díaz M. Victoria , Torres Tomas
Published: February 2020

An approach for employing SubPcs and SubPc fused dimers [1] as active units in molecular recognition of fullerenes and artificial photosynthetic systems has been developed. Thus, the preparation of multi-SubPc systems constituted by SubPc and SubPc fused dimer units connected by their mutual axial positions has been explored. For this purpose, a series of SubPcs and SubPc dimers bearing different conjugated spacers linked by alkyne bonds to the SubPc or SubPc dimer boron atoms have been synthesized. Two multi-SubPc hybrids comprised of a perfluorinated SubPc fused dimer (syn or anti topoisomer) axially functionalized with unsymmetrical octylthio-substituted SubPcs linked through their periphery by ethynyl linkers to the boron atoms of the dimer have been prepared. Electrochemical and steady state photophysical studies of the syn- hybrid suggest the existence of an electron transfer process from SubPc units to photoexcited SubPc dimer to generate a (SubPc•+-SubPc Dimer•-) radical pair.

Furthermore, the position that the two axial SubPc units acquire in this assembly gives rise to unique supramolecular recognition sites suitable for the complexation of fullerenes. Thus, the binding ability of this hybrid towards different fullerene derivatives, namely C60
, C70
, C60-PCBM and C70-PCBM, has been analyzed through UV-vis absorption, fluorescence and NMR titrations. It has been demonstrated that syn-compounds display a unique fullerene complexation mode. Initially, the formation of a 1:1 supramolecular complex, where the axial octylthio-substituted SubPcs embraces a guest molecule with remarkable association constants of around 106 - 104 M-1, is observed. The spatially-defined cavity generated by the rigid and short alkynyl linkers shows a higher affinity for the bigger fullerene derivatives. Then, a secondary supramolecular interaction between the perfluorinated SubPc syn dimer unit and another fullerene molecule has been detected and quantified, with significant binding constants of 104-103 M-1 that depend on the size and the host-guest electrostatic interactions, leading to the formation of the final 1:2 supramolecular ensemble [2].

[1] C. G. Claessens, D. González-Rodríguez, M. S. Rodríguez-Morgade, A. Medina, T. Torres, Chem. Rev.
2014,
114, 2192–2277.

[2] G. Zango, V. Mariñas, M. V. Martínez-Díaz, D. Guldi, T. Torres, in preparation
High-Performance Flexible Supercapacitors Based on Hair Fiber-Shaped Electrode
Authors: Liu Wenwen , Zhang Maiwen , Yu Aiping
Published: February 2020

In order to meet the new demand of wearable/stretchable electronic devices, supercapacitors, especially the fiber-shaped supercapacitors, have caused consideration attention. However, it is still a huge challenge to construct the fiber-shaped supercapacitors with outstanding performances at this stage. Meanwhile, the current performance of fiber-shaped supercapacitors is still not satisfactory such as low energy density, poor cycle stability, and poor cycle stability. To address these issues, we designed and constructed a flexible all-solid-state asymmetric supercapacitor with human hair/Ni/Graphene/MnO2 fiber as positive electrode and human hair/Ni/Graphene fiber as negative electrode. Excitingly, the resulting supercapacitors displayed large potential window up to 1.8 V, excellent rate capability, fast frequency response capability (With short relaxation time constant of 55 ms), high volumetric energy density, and long cycle stability (more than 90% retention after 10000 cycles). The method presented here not only provides a reference for the design of flexible supercapacitors, but also paves a new way for the preparation of other energy storage devices.
(Invited) Advanced Nanostructured Electrode Materials for Lithium-Sulfur Batteries
Authors: Chen Zhongwei
Published: February 2020

Advanced battery technology plays key roles in pursuit of sustainable energy future by electrifying the transportation fleet and converting/storing the intermittent green energy source in grid scale. Among the candidates, lithium-sulfur (Li-S) battery has risen up as a particularly promising successor to the currently dominating lithium-ion batteries due to its intriguingly high energy density and cost effectiveness. However, the practical implementation of Li-S battery can be achievable only when several critical problems are well addressed, which involve the insulting nature of cathode materials, the unruly polysulfide shuttling behavior, low efficiency of metallic lithium redox reactions, etc. These bugbears have been haunting the Li-S system and obstructing its access to practically high capacity and long lifespan.

Targeting at these problems, we have long been committed to pursuing high-efficiency Li-S electrochemistry with extensive research interests in multiple battery ingredients. Following the two strategic emphasis on conduction properties and sulfur confinement, a series of functional host materials with delicate nano-/micro-structures has been successfully developed to fulfill fast and durable sulfur electrochemistry, which enables high sulfur loading and minimum electrolyte with achievable energy density that meets the commercial benchmark. Beyond that, targeted surface functionalization has been dedicated on separator to regulate the diffusion behavior of polysulfide, while host strategy with rationally-designed architecture has been also employed in lithium anode to suppress the dendrite formation and enhance the redox reversibility. Through the multi-sectional improvements, we are aiming at the establishment of an interoperable mechanism at a system level to promote the fundamental understanding as well as the practical electrochemical performance of Li-S battery for future commercialization.
(Invited) Nanostructured Materials for Higher Energy and Higher Power Lithium-Ion Batteries
Authors: Yushin Gleb
Published: February 2020

Energy density and cost of Li-ion batteries (LIBs) based on conventional intercalation compounds are closely approaching their limits. The reliance of conventional cathodes on the use of toxic metals additionally endangers health and safety of miners in developing countries. Conversion-type active materials offer an opportunity to double energy stored in LIBs, reduce their cost by the same factor, and improve cell safety. These materials may be produced from safer, cheaper and globally available resources and contribute to accelerated adoption of electric vehicles (EVs). Critically important for the adoption by LIB manufacturing industry, novel materials must serve as drop-in replacements and be fully compatible with existing electrode and cell assembling technologies. Their use should not require additional steps or modified procedures, which often increase production cost and most importantly induce highly-undesired safety or yield risks. As such, all the critical limitations of novel conversion-type materials (large volume changes, undesirable interactions with electrolyte, mechanical instability, slow ion transport, slow electron transport, etc.) should be resolved on the individual particle level via formation of nanocomposites. In order to enable sufficiently low synthesis cost, such nanocomposite particles should be produced using the low-cost bulk reactors and well-established powder production methodologies. Such a strategy enabled success of Sila Nanotechnologies, Inc. to develop and commercialize production of silicon (Si) - based anode materials that experience minimal volume changes and remarkable electrochemical stability during cycling in matched full cells of various sizes.
(Invited) Nano Carbon and Polymeric Materials for Energy Conversion and Storage
Authors: Chen Yongsheng
Published: February 2020

Green energy technologies have been highly demanded for a sustainable development. In this talk, our recent studies for the electricity conversion/storage using nano carbon and polymeric materials will be presented. These will include the material design, synthesis, and device fabrication, targeting for high energy efficiency and understanding the mechanism using simpler or cheap materials.

Recent five references:

"Polymeric Graphene Bulk Materials with a 3D Cross-Linked Monolithic Graphene Network", Wangqiao Chen, Peishuang Xiao, Honghui Chen, Hongtao Zhang, Qichun Zhang, and Yongsheng Chen*,
Mater
., 2018, 1802403.

"Nonfullerene Tandem Organic Solar Cells with High Performance of 14.11%", Lingxian Meng, Yamin Zhang, Xiangjian Wan*, Chenxi Li, Xin Zhang, Yanbo Wang, Xin Ke, Zuo Xiao, Liming Ding*, Ruoxi Xia, Hin-Lap Yip, Yong Cao, Yongsheng Chen*,
Science
, 2018, 361, 1094-1098.

"Monolithic 3D Cross-linked Polymeric Graphene Materials and the Likes: Preparation and Their Redox Catalytic Applications",Yanhong Lu, Yanfeng Ma, Tengfei Zhang, Yang Yang, Lei Wei, and Yongsheng Chen ,
Am. Chem. Soc., 2018, 140 (37), pp 11538–11550.

"Ultra-Broadband Wide-Angle Terahertz Absorption Properties of 3D Graphene Foam",Zhiyu Huang, Honghui Chen, Yi Huang,* Zhen Ge, Ying Zhou, Yang Yang, Peishuang Xiao, Jiajie Liang, Tengfei Zhang, Qian Shi, Guanghao Li, and Yongsheng Chen, Funct. Mater. , 2017, 1704363

“Macroscale light propulsion of 3D cross-linked graphene ”, Tengfei Zhang†, Huicong Chang†, Yingpeng Wu†, Peishuang Xiao, Ningbo Yi, Yanhong Lu, Yanfeng Ma, Yi Huang, Kai Zhao, Xiaoqing Yan, Zhibo Liu, Jianguo Tian and Yongsheng Chen*,
Nature Photon., 2015, 9, 471-476
Study on Corrosion and Cavitation Behaviors of NiTi Alloy Coated on Steel
Authors: Zeng Qunfeng , Gu Yanhong
Published: February 2020

The aim of the present paper is to investigate the corrosion and cavitation behaviors of NiTi alloy sample. NiTi alloy coated high speed steel (HSS) with 2 mm thickness layer has a good corrosion resistance in artificial seawater used as an electrolyte solution. During the tests, a film on the surface of sample was formed, which protects from the corrosion as compared with the two other sample such as HSS and NiTi alloy coated HSS with 1.2 mm thick layer, it was concluded that NiTi alloy coating with 2 mm thick exhibits excellent corrosion resistance in the artificial solution at room temperature. From SEM analysis it is confirmed that the oxide film was formed on NiTi alloy coatings with 2 mm thickly of sample. In artificial sea water, the components of the oxide film are Ti2 and Ni (OH).
Acridin-Based Thiosemicarbazones As Novel Corrosion Inhibitors in the Corrosion of Mild Steel in 1M HCl: Synthesis, Gravimetric, Electrochemical, and Quantum Chemical Studies
Authors: Akpan Ekemini Daniel , Isaac Ibanga Okon , Olasunkanmi Lukman Olawale , Ebenso Eno E
Published: February 2020

Electrochemical, surface morphology, density functional theory and Monte Carlo simulation methods were employed in investigating the effects of (2E,2'E)-2,2'-(3,3,6,6-tetramethyl-9-phenyl-3,4,6,7-tetrahydroacridine-1,8(2H,5H,9H,10H)-diylidene)bis(N-phenylhydrazinecarbothioamide) (IAB-NP), (2E,2'E)-2,2'-(3,3,6,6-tetramethyl-9-phenyl-3,4,6,7-tetrahydroacridine-1,8(2H,5H,9H,10H)-diylidene)bis(N-(2,4-difluorophenyl)hydrazinecarbothioamide) (IAB-ND) and (2E,2'E)-2,2'-(3,3,6,6-tetramethyl-9-phenyl-3,4,6,7-tetrahydroacridine-1,8(2H,5H,9H,10H)-diylidene)bis(N-(2-fluorophenyl) hydrazinecarbothioamide) (IAB-NF) on mild steel corrosion in 1 M HCl solution. From the studies, compounds IAB-NP, IAB-ND and IAB-NF inhibit mild steel corrosion in the acid and the protection efficiencies were found to increase with increase in concentrations of each compound. At the optimum inhibitor concentration of 0.15 mM, the inhibition efficiencies of the compounds are in the order IAB-NF IAB-ND IAB-NP. Potentiodynamic polarization measurements revealed that all the compounds acted as mixed-type corrosion inhibitors. Experimental data for the adsorption of the studied molecules on mild steel surface in 1 M HCl fitted into the Langmuir adsorption isotherm and the standard free energies of adsorption suggested both physisorption and chemisorption mechanisms. Scanning electron microscopy analyses confirmed the formation of protective film on the mild steel surface by the inhibitor molecules, resulting in protection of the metal from corrosive electrolyte ions. The experimental findings were corroborated by both theoretical density functional theory and Monte Carlo simulation studies.
Aromatic Disulfide Based Compounds As Corrosion Inhibitors for Steel in Acidic Media
Authors: Karunarathne Darshan , Golden Teresa D
Published: February 2020

Organic corrosion inhibitors are widely used to decrease the corrosion rates of steels in acidic conditions. In this study, inhibitive performance of three organic disulfide compounds as novel corrosion inhibitors for steel in acidic media have been studied. Generally, it is widely accepted that the inhibition of organic corrosion inhibitors is dependent upon the structure of the organic molecule. The inhibition process proceeds through a passive organic film formation on the metal surface. Compounds with electronegative atoms (N, O, and S) and aromatic ring systems facilitates the film formation on metal substrate, improving corrosion inhibition. Compared with other corrosion inhibitors, aromatic disulfide compounds provide corrosion inhibition through two pathways. First pathway is the chemical adsorption through the π-bonds in aromatic ring which can interact with free 3d orbitals of iron and the second pathway through the chemical adsorption by S atoms in disulfide bonds. Disulfide bond can enhance the corrosion inhibition by forming dπ- dπ bonds through the overlap of 3d electrons in Fe atom and vacant 3d orbitals of S atoms. Addition of polar groups to the disulfide compounds make these compounds more water soluble than the previously reported disulfides. Furthermore these disulfide compounds can be synthesized easily from relatively cheap material which makes these compounds economically feasible. To evaluate the inhibitive effect of the disulfides, steel samples have been subjected to immersion tests in HCl. Different HCl concentrations have been used as the acidic medium for immersion tests because it is the most common acidifying reagent used in the oil and gas industry. Various inhibitor concentrations and immersion times have been used to estimate the inhibitor efficiencies. Potentiodynamic polarization and electrochemical impedance spectroscopy have been utilized to measure the corrosion properties. Scanning electron microscopy, x-ray photoelectron spectroscopy and infrared spectroscopy have been used to study the steel surface before and after the immersion tests.

Figure 1
Galvanic Aluminum Bond Pad Corrosion in Copper Wire Bonded Device Assembly – Mechanism and Prevention
Authors: Chyan Oliver , Asokan Muthappan , Thompson Zach , Lambert Alexander , Ross Nick
Published: February 2020

The explosion of microelectronics use in automobiles has made the microelectronic corrosion control more critical over the past decade. Wire bonded devices form an integral part of the microelectronic systems used in automobiles. With the reliability requirements of automobile microelectronics pushing towards ppb levels of failure, halide induced corrosion issues have to be controlled to achieve such high reliability goals. The corrosion of Aluminum bond pads in slightly acidic chloride solutions (ppm level) has been one of the main modes of wire-bonding failure in wire bonded devices. Earlier researches pointed out the possibility of intermetallic compound formation as the main reason for this corrosion. However, our investigation of the electrochemical nature of the corrosion led to the discovery that bimetallic contact of the aluminum bond pads with copper wires is the main reason for this type of corrosion. Copper and Aluminum being apart in the galvanic series can act as a galvanic corrosion cell under suitable conditions. Furthermore, the presence of halides causes de-passivation of Aluminum oxide layer making the Aluminum bond pad more susceptible to corrosion.

In this report we introduce corrosion screening as a mimicking platform for studying wire-bond device corrosion. For the first time we reported that Hydrogen evolution is the cathodic reaction and is responsible for the explosive nature of this bond pad corrosion. By selective surface treatment of the Cu wires (cathodic part), we were able to prevent the corrosion by blocking the cathodic reaction and thereby stopping the electron flow required for the corrosion cycle to continue. The prevention treatment was then applied to commercial wire-bonded device and excellent corrosion prevention was observed. The corrosion inhibition coating exhibited high thermal stability up to 260
O
C.

We also report a novel testing method for corrosion testing of molded wire-bonded device with internal chloride ion contamination. Electrical continuity and delamination analysis showed that the chosen method of inhibition treatment was able to prevent corrosion even in cases of high chloride contamination and severe delamination. The results of the Pressure Cooker Test showed that the inhibitor coating is suitable for prevention of corrosion in even 100% Relative Humidity environments. Work is now in progress to apply these treatments to Palladium coated Copper wire bonded devices to check corrosion prevention ability of the reported corrosion prevention treatment.
Electrochemical Behavior of Stainless Steels in Highly Concentrated Electrolytes
Authors: Tsuchiya Hiroaki , Tokuoka Satoshi , Fujimoto Shinji
Published: February 2020

Due to the superior mechanical properties and corrosion resistance of stainless steels, their application as exterior material and current collector has been examined. Recently, concentrated aqueous solutions of lithium salts are highly expected as a novel electrolyte because they allow the safe operation of lithium ion batteries, different from conventional organic solvent based electrolytes. Therefore, understanding on the electrochemical behavior of stainless steels in concentrated aqueous solutions is crucial to judge the applicability of stainless steels to lithium ion batteries. It is well-known that electrochemical behavior of metals in concentrated aqueous solution is different from that in dilute aqueous solution. The difference is considered to be attributed to chemical state of water molecules. In the present work, electrochemical behavior of stainless steels in highly concentrated aqueous solution of lithium trifluoromethanesulfonate was examined.