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A chemical bottom-up approach for single-atomic-layered materials like graphene is attractive due to the possibility of introducing functions. This article includes the synthesis and properties of borophene-oxide and metalladithiolene layers, which are reported as inorganic materials. They have graphene-like two-dimensional networks that enable conjugated structures. Their atomically thin layers are also available by dissolution or synthetic methods. Their two-dimensional electronic features are evaluated from the activation energies for electrical conduction, focusing on the anisotropic features of borophene-oxide layers and the switching abilities of metalladithiolene layers. [ABSTRACT FROM AUTHOR]

The high efficiency of precursor-to-perovskite conversion is one of the core factors in boosting the performance of perovskite solar cells (PSCs). Herein, we report a liquid/liquid interfacial synthesis of terpyridine-zinc(II) (ZnTPY) coordination nanosheets (CONASHs), which can enhance PbI2-based perovskite crystallization and thus the efficiency of PSCs. Ultrasonically fragmented ZnTPY CONASHs, rich in uncoordinated terpyridine moieties, caused multidentate chelation with PbI2, resulting in a well-dispersed ZnTPY:PbI2 complex. This metal-organic complex could act as a heterogeneous nucleation seed and facilitate the formation of a PbI2-to-[PbI6−x]4− coordinated octahedral framework in a precursor solution of perovskite, thereby reducing the crystallization barrier of tetragonal CH3NH3PbI3 perovskites and achieving a complete precursor-to-perovskite conversion. Consequently, ZnTPY-capped perovskite crystals had a long photoluminescence (PL) lifetime, which is attributed to the more passivated trap states associated with ZnTPY. The corresponding PSCs exhibited an optimal power conversion efficiency of 19.8% compared with 17.9% of the controlled device. The results prove that the performance of PSC families can be improved by dispersing PbI2 in a solution with CONASHs for enhancing the PbI2-to-perovskite conversion. [ABSTRACT FROM AUTHOR]

The luminescence of stable radicals can be enhanced by coordination to metal complexes. The 4% fluorescence quantum yield of (3,5-difluoro-4-pyridyl)bis(2,4,6-trichlorophenyl)methyl radical (F2PyBTM) in dichloromethane was enhanced up to 36% by coordination to AuI with N-heterocyclic carbene ligand, which is a record for metal-radical complexes. [ABSTRACT FROM AUTHOR]

A ZnII complex based on a luminescent organic radical was doped into host molecular crystals. The 5, 10, and 20 wt%-doped crystals showed excimer emissions and their luminescent behaviours were significantly modulated by an external magnetic field. These are the first examples showing excimer emissions and magnetic-field–sensitive luminescent properties for complexes based on luminescent radicals. The excimer species contributing to magnetoluminescence was determined by analyzing the emission spectra and their magnetic-field dependencies. These results suggest the general nature of magnetic field effects on the luminescence of radicals as well as the importance of the type of interaction between radicals. [ABSTRACT FROM AUTHOR]

A liquid/liquid interfacial method is used to synthesize a conjugated porous polymer nanofilm with a large domain size. Copper-catalyzed azide–alkyne cycloaddition between a triangular terminal alkyne and azide monomers at a water/dichloromethane interface generates a 1,2,3-triazole-linked polymer nanofilm featuring a large aspect ratio and robustness against heat and pH. [ABSTRACT FROM AUTHOR]

Prussian blue (PB) is a well-known porous metal–organic framework (MOF) material, whose redox chemistry on indium-tin oxide (ITO) electrodes has been studied extensively. However, the molecular interfacing of PB nanocrystals has not yet been explored in such detail. In this study, electrochemical interfacing of PB nanocrystals with a thin film containing a redox-active Ru complex (Ru-NP) was investigated. Spontaneous growth of preferentially oriented PB nanocrystals was observed on an ITO electrode modified with a Ru-NP primer film, which was subsequently characterized by UV-Vis-NIR spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis. Blocking and rectification of electron transport (ET) were observed between PB and the Ru complex, and this behavior was governed by the energy gap between the Ru complex and PB nanocrystals as well as the thickness of the Ru-containing primer layer film. ET rectification at the ITO‖(Ru-NP)3/PB heterojunction was supported by a potential-step chronoamperometry (PSCA) analysis of the i–t curves. Owing to the large difference between the forward and backward ET rates at the ITO‖(Ru-NP)3/PB heterojunction, a large hysteresis loop was observed during electrochemical quartz crystal microbalance (EQCM) measurements, indicating dynamic ion transfer gating in the PB nanopores through the rectified electron transport between the Ru-NP layer and the ITO electrode at the ITO‖(Ru-NP)3/PB heterojunction. [ABSTRACT FROM AUTHOR]

Two bottom-up Co(ii) complex nanosheets Co-S1 and Co-S2 were prepared by coordination of trifunctional terpyridine-based triphenylamine derivatives (L1 and L2) and a cobalt(ii) ion, in order to demonstrate the structural flexibility and functional tunability of these nanosheets over the top-down type. A liquid–liquid interface-assisted synthesis was employed, which is a facile method to generate multi-layer nanosheets. The nanosheets formed were characterized, revealing the proposed sheet morphology and uniform composition. They have large size domains and good mechanical strength. Besides, both Co-S1 and Co-S2 show reversible electrochromism. The color of Co-S1 was switched from red to green while that of Co-S2 was changed from light red to orange when a positive voltage was applied. An electrochromic device was also fabricated with Co-S1, indicating the promising application of these kinds of structurally tunable, easy-processable and stable nanosheets as low-cost and solid-state electrochromic materials. [ABSTRACT FROM AUTHOR]

The one-dimensional coordination polymer composed of CuII and an organic radical bisPyTM displayed temperature dependent Jahn–Teller distortion, which is correlated to the π-conjugation mode at the ligand as well as the magnetic properties. The ferromangetic bisPyTM–CuII interaction was enhanced by the reorientation of the CuII dx2−y2 orbital at low temperature. [ABSTRACT FROM AUTHOR]

A graphdiyne (GDY) analogue that features pyrazine as the aromatic core (PR-GDY) was synthesized under air using a liquid/liquid interfacial synthesis. Optical microscopy, SEM, and AFM revealed the sheet morphology of PR-GDY with a typical thickness of 20 nm in AFM, while TEM disclosed its amorphous nature. It served as a metal-free electrocatalyst for the hydrogen evolution reaction (HER) from water. The presence of the butadiynyl linker and terminal ethynyl group, respectively, was confirmed by Raman spectroscopy. Polymerization to PR-GDY afforded optical bandgap narrowing compared with the corresponding monomer. XPS provided a ratio of 2 : 1 for the sp and sp2 carbons. Moreover, a single Gaussian was fitted with the N 1s peak, ascribable to the pyridinic nitrogen. Such selective doping of heteroatoms is hard to realize in carbon materials. PR-GDY was subjected to TGA, such that its thermal stability up to 300 °C was confirmed. N2 adsorption–desorption isotherms featured a typical type I adsorption behavior with micropores, with a Brunauer–Emmett–Teller surface area and mean pore size of 408 m2 g−1 and 0.8 nm, respectively. A series of electrochemical measurements were conducted to evaluate the HER activity of PR-GDY. The HER performance of GDY was only slightly better than that of glassy carbon, while that of PR-GDY was improved significantly in both acidic and basic aqueous media with an onset potential of −275 mV (vs. the reversible hydrogen electrode, RHE), and −475 mV to achieve a current density of 10 mA cm−2 in 0.5 M H2SO4, and –270 and −710 mV in 0.1 M NaHCO3 + 0.1 M Na2CO3. The present work demonstrates experimentally that PR-GDY serves as a metal-free HER electrocatalyst, and manifests that pyridinic nitrogen enhances the electrocatalytic activity of carbon materials. [ABSTRACT FROM AUTHOR]

Pyridyl-substituted triarylmethyl radicals exhibited cation-responsive turn-on fluorescence when additional pyridyl rings were incorporated at an appropriate position; the mechanism of fluorescence enhancement is examined. Reduced quenching by internal and external heavy atom effects is proposed as a unique property of fluorescent radicals, which can be utilized in different environments to conventional closed-shell fluorescent molecules. [ABSTRACT FROM AUTHOR]

The titled complex exhibits multi-functional luminochromism in the solid state, despite its simple chemical structure. The complex shows solid-state vapochromism and mechanochromism. The polymer analogue of the complex undergoes solvatochromism and thermochromism. [ABSTRACT FROM AUTHOR]

Imine-linked BODIPY oligomers show fluorescence quantum yields of up to 0.93. The azine linker may mediate π-conjugation that extends over six BODIPY units with redshifts up to 125 nm. BODIPYs are immobilized on silica gel through heterogeneous imine-bond formation, being fluorescent and robust. [ABSTRACT FROM AUTHOR]

Nanosheets, which are two-dimensional polymeric materials, remain among the most actively researched areas of chemistry and physics this decade. Generally, nanosheets are inorganic materials created from bulk crystalline layered materials and have fascinating properties and functionalities. An emerging alternative is molecule-based nanosheets containing organic molecular components. Molecule-based nanosheets offer great diversity because their molecular, ionic, and atomic constituents can be selected and combined to produce a wide variety of nanosheets. The present article focuses on coordination nanosheets (CONASHs), a class of molecule-based nanosheets comprising organic ligand molecules and metal ions/atoms in a framework linked with coordination bonds. Following the Introduction, Section 2 describes CONASHs, including their definition, design, synthetic procedures, and characterisation techniques. Section 3 introduces various examples of CONASHs, and Section 4 explores their functionality and possible applications. Section 5 describes an outlook for the research field of CONASHs. [ABSTRACT FROM AUTHOR]

The authors create a zinc(ii) complex featuring a simple chemical structure but multi-functional luminochromism. Reversible dissociation/association between the zinc center and the terpyridine ligand plays a key role in the multi-functional luminochromism. [ABSTRACT FROM AUTHOR]

A rational molecular design for open-shell molecules to enhance their luminescence efficiency was developed. Introduction of fluorine atoms and coordination of gold(i) to PyBTM, a highly stable fluorescent radical containing a pyridyl moiety, synergistically contributed to yield ten times increase of its fluorescence quantum yield (2 → 20%). [ABSTRACT FROM AUTHOR]

Bottom-up approaches have gained significant attention recently for the creation of nano-sized, ordered functional structures and materials. Stepwise coordination techniques, in which ligand molecules and metal sources are reacted alternatively, offer several advantages. Coordination bonds are stable, reversible, and self-assembling, and the resultant metal complex motifs may contain functionalities unique to their own characteristics. This review focuses on metal complex wire systems, specifically the bottom-up fabrication of linear and branched bis(terpyridine)metal complex wires on electrode surfaces. This system possesses distinct and characteristic electronic functionalities, intra-wire redox conduction and excellent long-range electron transport ability. This series of comprehensive studies exploited the customizability of bis(terpyridine)metal complex wires, including examining the influence of building blocks. In addition, simple yet effective electron transfer models were established for redox conduction and long-range electron transport. A fabrication technique for an ultra-long bis(terpyridine)metal complex wire is also described, along with its properties and functionalities. [ABSTRACT FROM AUTHOR]

Heteroleptic bis(dipyrrinato)copper(ii) and nickel(ii) complexes are synthesized. Their structures are determined by X-ray diffraction analysis, and their properties are investigated by using cyclic voltammetry, chronocoulometry, and UV/vis absorption spectroscopy. [ABSTRACT FROM AUTHOR]

Dipyrrins serve as monovalent bidentate ligand molecules that coordinate to various cations. Their BF2 complexes, 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene and its derivatives (BODIPYs), exhibit excellent photostability, strong light absorption, and high fluorescence quantum yield, thereby encouraging their application in various fields, e.g., as biological and biomedical fluorescent markers. Dipyrrin may also accept a wide variety of metal ions spontaneously. However, dipyrrin metal complexes have been disregarded from materials science research. This review article summarizes recent progress in bis(dipyrrinato)metal(ii) and tris(dipyrrinato)metal(iii) complexes from the viewpoint of materials chemistry. Section 2 describes a series of efforts aimed to realize intense luminescence superior to or comparable with that of BODIPYs. The spontaneous coordination of these complexes enables them to construct self-assembled nanoarchitectures, such as supramolecules and coordination polymers that form one-dimensional nanowires, two-dimensional nanosheets, and metal–organic frameworks. Section 3 describes such alluring molecular superstructures. Section 4 discusses potential applications based on these nanoarchitectures, such as thermoelectric and photoelectric conversion. [ABSTRACT FROM AUTHOR]

Fully oxidized poly(1-(N,N-dimethylamino)pyrrole)s (PDMAPyn+), which are synthesized through doping with anions with the same number of polymer units as the original pyrrole, have been proposed as candidates for molecular flat-band magnets from the theoretical calculations of Aoki and coworkers (Phys. Rev. B: Condens. Matter Mater. Phys., 2003, 68, 140403; Phys. Rev. B: Condens. Matter Mater. Phys., 2010, 82, 235127). Here we describe the synthesis of neutral forms of oligo(1-(N,N-dimethylamino)pyrrole)s (ODMAPys) from the dimer (2) to the dodecamer (12). The crystal structures of 2–6 (i.e., up to the hexamer) were determined by single crystal X-ray analysis. The chemical and electrochemical formation of their oxidized forms is also reported. Electrochemical measurements of the ODMAPys indicated that oligomers 4, 6, and 8 underwent 2e− oxidation, whereas 10 and 12 showed quasi-reversible 4e− oxidation. The oxidized forms maintained considerable chemical stability; 42+, 62+, 82+, 104+, and 124+ were isolated as SbCl6− salts. The neutral forms were colorless (λmax = 240–270 nm), whereas the oxidized forms exhibited strong blue color with λmax = 670–950 nm. EPR spectroscopy indicated that the dications 42+, 62+, and 82+ in the solid salts were intrinsically diamagnetic, but the tetracation of 104+ was paramagnetic at 4.4 K, which was supported by magnetic measurements. These physical properties of the ODMAPys are different from those common to polypyrroles, but consistent with their predicted unique electronic structures. [ABSTRACT FROM AUTHOR]

Two π-conjugated dimethyldihydropyrene (DHP)-bis-terpyridine ligands (2 and 3) were prepared, in which two terpyridine moieties were connected at the 4 and 9 positions of DHP (1) via phenyl and ethynyl linkers, respectively. The nature of the π-conjugated linkers influenced the valence orbitals of the DHP moiety, which shifted the redox potentials of the DHP moiety and the absorption spectra. In 3 with an ethynyl linker, the redox potentials of the DHP moiety were shifted in the positive direction and the absorption band was largely red-shifted compared with 1. In 2 with a phenyl linker, the shifts in the redox potentials of the DHP moiety and in the absorption band were moderate. These results were supported by valence orbital energies calculated using time-dependent density functional theory, which enabled the assignment of the four main transitions in each spectrum for the first time. The fluorescence intensity of 3 was larger than that of 2, which was photoisomerisable. Two dinuclear Ru(bis-terpyridine) complexes (4 and 5) were prepared from 2 and 3, and their redox and photochemical properties were investigated. [ABSTRACT FROM AUTHOR]

A bis(terpyridine)iron network polymer was fabricated by electropolymerisation on a glassy carbon electrode. The modified electrode allowed high-speed charging and discharging with a minor capacity decay (only 5% after 3000 cycles at 1 V s−1). [ABSTRACT FROM AUTHOR]

Correction for 'Electrochromic triphenylamine-based cobalt(II) complex nanosheets' by Yurong Liu et al., J. Mater. Chem. C, 2019, 7, 9159–9166, DOI: 10.1039/C9TC02257K. [ABSTRACT FROM AUTHOR]

This paper summarizes the results of our recent studies on the development of an artificial molecular rotor system that exhibits a change in redox potential and photoluminescence in response to external stimuli such as heat and photons. The molecular rotor is made of copper complexes bearing two bidentate ligands; the rotor is described here as [Cu(Rpmpy)(Lx)]+, where Rpmpy and Lx are a 4-methyl-2-(2′-pyridyl)pyrimidine derivative and a bidendate ligand with bulky moieties, x, respectively, and the pyrimidine ring can rotate beside the copper centre while maintaining the pyridine–copper connection. The simplicity of the system enabled us to design the rotating motion more accurately. We expected that placing a wall in the rotational trajectory in the Lx moiety would decrease the rate of the rotational dynamics. This slow rate of rotation was a key factor in achieving an external-stimuli-induced switching from thr equilibrium to metastable states. This switching was based on four stable isomers derived from the rotation and oxidation states, the behaviours of which were characterized for isolated copper(i) complexes using spectroscopic and electrochemical measurements at several temperatures. The steric shifts arising from the ring rotation were exploited not only to exhibit well-established oxidation-triggered motion but also to modulate the rest potential of the electrode, to manipulate the intramolecular electron transfer, to develop a redox potential switch based on photo-driven rotation, and to demonstrate the dual-luminescence behaviour. [ABSTRACT FROM AUTHOR]

3-Ferrocenylazobenzene (3-FcAB)-containing polymers were prepared using solution polymerization and emulsion polymerization. Polymer A, prepared by solution polymerization followed by re-precipitation, and Polymer B, prepared by emulsion polymerization, had spherical shapes with the outer diameters of ca.300 nm and ca.20 nm, respectively. Both the polymers responded to green light, UV light, and blue light in solution like monomeric 3-FcABand its derivatives. In the solid state, Polymer Aexhibited both isomerization and re-orientation behaviors upon light irradiation, indicating a possibility to achieve a light-induced shape change by the re-orientation of the chromophore. On the other hand, Polymer Bunderwent simple photoisomerization behaviors, which is more preferable for developing a switching system using spectroscopic detection of the isomerization behaviors of nano-dots. [ABSTRACT FROM AUTHOR]

Triangular trinuclear Co(III), Rh(III), and Ir(III) dithiolene complexes, [[M3(η5-C5Me5)3(S6C6)] (M = Co, Rh, Ir), which have not been obtained by the trimerization of mononuclear complexes, were synthesized via a new synthetic route, that is, the reaction of benzenehexathiol and [(η5-C5Me5)Co(CO)I2], [Rh(η5-C5Me5)Cl2]2 and [Ir(η5-C5Me5)Cl2]2, respectively, under basic conditions. Single crystal X-ray diffraction measurements were carried out and their crystal structures were determined. Electrochemical measurements revealed that the trinuclear complexes exhibit three-step one-electron redox reactions and form mixed valence complexes. Studies on the stabilities of their mixed valence states and the X-ray crystal structure analyses revealed that the through-bond internuclear electronic interaction and the aromaticity of central benzene ring decrease in the order of Co > Rh > Ir. [ABSTRACT FROM AUTHOR]

We describe the two correlated rotational motions of pyrimidine rings in 4,4′-dimethyl-2,2′-bipyrimidine ligated to Cu(I). The two pyrimidine rings delimited by anthryl and phenanthroline groups rotate to afford three isomers. 1H NMR measurements revealed that the two rotational processes were activated at different temperatures. Cyclic voltammetry gave the kinetic and thermodynamic parameters that provide clear evidence of the correlation between the two rotational steps. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the editor discusses various reports within the issue on topics including the design and characteristization of single-molecules, the impact of chemical anchoring on molecular junctions' electronic properties, and single-molecule transistors.

Asymmetric, heteroleptic dinuclear bis(dipyrrinato)zinc(ii) complexes were synthesized and demonstrated to collect a wide range of light across the UV and visible regions (340–655 nm). The complexes also conveyed excitons across their structure from one end to the other, with spectroscopic studies demonstrating quantitative and fast energy transfer. [ABSTRACT FROM AUTHOR]

A palladium-catalyzed arylation of hydrosiloxanes was developed for the synthesis of symmetrical and unsymmetrical siloxanes. Reactive functional moieties such as hydroxy or cyano groups were able to tolerate the reaction conditions and several novel unsymmetrical siloxanes were synthesized in moderate to high yield. [ABSTRACT FROM AUTHOR]

The present work reports a tripodal scaffold for bis(terpyridine)–Fe(ii) oligomer wires on an Au(111) surface: the tripodal scaffold realised both orthogonality of the oligomer wires, and fast interfacial electron transfer through the oligomer wires. [ABSTRACT FROM AUTHOR]

Alkyl iodides and tertiary silanes were successfully coupled with good functional group tolerance using a Pt(P(tBu)3)2/(iPr)2EtN/CH3CN system. The utility of the methodology is demonstrated by the synthesis of silafluofen, a Si-containing insecticide. [ABSTRACT FROM AUTHOR]

Linear and branched Fe(tpy)2complex oligomer wires were quantitatively formed on hydrogen-terminated silicon wafers by means of hydrosilylation of ethynylterpyridine and following stepwise coordination reactions, and the redox property of surface-attached species and its photosensitivity can be controlled by the doping density of the silicon wafers. [ABSTRACT FROM AUTHOR]

Iron(ii) complexes of Z- and E-2,6-di(1H-pyrazol-1-yl)-4-styrylpyridine (Z-2and E-2, respectively) exhibited visible light photoisomerization from Z-2to E-2, both in solution and in solid phases. Z-2occupied the high-spin state over the full temperature range examined, whereas E-2displayed a spin crossover phenomenon between 100 K and 300 K. [ABSTRACT FROM AUTHOR]

Protonation of a new platinum complex, Pt(1-pdtAq)(tBu2bpy), where 1-pdtAq is 1-(phenyldithiolenethynyl)anthraquinone, afforded a cyclized structure, [Pt(1-pdtPyl)(tBu2bpy)]+, with a unique electronic structure due to intense intramolecular charge transfer. [ABSTRACT FROM AUTHOR]

The dynamic bistable rotational behaviour of a copper(i) coordination environment can be rationally tuned with balancing the substituent size on the rotor. Such rotors are sensitive to weak interactions, and the rotation was driven by a redox reaction on a ferrocenyl moiety viareconstruction of the charge interaction between redox centres. [ABSTRACT FROM AUTHOR]

The treatment of aryl iodides with tris(trimethylsilyl)silane in the presence of Pd(P(tBu)3)2and the Hünig base leads to the formation of hypersilylated aromatic products in good to excellent yields without cleavage of weak Si–Si bonds under mild conditions. [ABSTRACT FROM AUTHOR]

Water-soluble luminescent AuNPs of 1.3 ± 0.3 nm in diameter with a large Stokes shift were facilely synthesized by a new molten matrix sputtering (MMS) method. [ABSTRACT FROM AUTHOR]

Correction for 'Electrochromic triphenylamine-based cobalt(II) complex nanosheets' by Yurong Liu et al., J. Mater. Chem. C, 2019, 7, 9159–9166. [ABSTRACT FROM AUTHOR]