Cationic Center Research Articles

Structural, Spectroscopic, and Thermal Decomposition Features of [Carbonatotetraamminecobalt(III)] Iodide—Insight into the Simultaneous Solid-Phase Quasi-Intramolecular Redox Reactions

[κ2-O,O′-Carbonatotetraamminecobalt(III)] iodide, or [Co(NH3)4CO3]I, named in this paper as compound 1, was prepared and characterized comprehensively with spectroscopic (IR, Raman and UV) and single-crystal X-ray diffraction methods. Compound 1 was orthorhombic, and isomorphous with the analogous bromide. The four ammonia ligands and the carbonate anion were coordinated to the central cobalt cation in a distorted octahedral geometry. The carbonate ion formed a four-membered symmetric planar chelate ring. The complex cations were bound to each other by N-H···O hydrogen bonds and formed zigzag sheets via an extended 2D hydrogen bond network. The complex cations and iodide ions were arranged into ion pairs and each cation bound its iodide pair through three hydrogen bonds. The thermal decomposition started with the oxidation of the iodide ion by CoIII in the solid phase resulting in [Co(NH3)4CO3] and I2. This intermediate CoII-complex in situ decomposed into Co3O4 and C-N bond containing intermediates. In inert atmosphere, CO or C-N bond containing compounds, and also, due to the in situ decomposition of CoCO3 intermediate, Co3O4 was formed. The quasi-intramolecular solid-phase redox reaction of [Co(NH3)4CO3] might have resulted in the formation of C-N bond containing compounds with substoichiometric release of ammonia and CO2 from compound 1. The C-N bond containing intermediates reduced Co3O4 into CoO and Co, whereas in oxygen-containing atmosphere, the end-product was Co3O4, even at 200 °C, and the endothermic ligand loss reaction coincided with the consecutive exothermic oxidation processes.

Tuning the Molecular Structure of Corroles to Enhance the Antibacterial Photosensitizing Activity.

The increase in the antibiotic resistance of bacteria is a serious threat to public health. Photodynamic inactivation (PDI) of micro-organisms is a reliable antimicrobial therapy to treat a broad spectrum of complex infections. The development of new photosensitizers with suitable properties is a key factor to consider in the optimization of this therapy. In this sense, four corroles were designed to study how the number of cationic centers can influence the efficacy of antibacterial photodynamic treatments. First, 5,10,15-Tris(pentafluorophenyl)corrole (Co) and 5,15-bis(pentafluorophenyl)-10-(4-(trifluoromethyl)phenyl)corrole (Co-CF3) were synthesized, and then derivatized by nucleophilic aromatic substitution with 2-dimethylaminoethanol and 2-(dimethylamino)ethylamine, obtaining corroles Co-3NMe2 and Co-CF3-2NMe2, respectively. The straightforward synthetic strategy gave rise to macrocycles with different numbers of tertiary amines that can acquire positive charges in an aqueous medium by protonation at physiological pH. Spectroscopic and photodynamic studies demonstrated that their properties as chromophores and photosensitizers were unaffected, regardless of the substituent groups on the periphery. All tetrapyrrolic macrocycles were able to produce reactive oxygen species (ROS) by both photodynamic mechanisms. Uptake experiments, the level of ROS produced in vitro, and PDI treatments mediated by these compounds were assessed against clinical strains: methicillin-resistant Staphylococcus aureus and Klebsiella pneumoniae. In vitro experiments indicated that the peripheral substitution significantly affected the uptake of the photosensitizers by microbes and, consequently, the photoinactivation performance. Co-3NMe2 was the most effective in killing both Gram-positive and Gram-negative bacteria (inactivation > 99.99%). This work lays the foundations for the development of new corrole derivatives having pH-activable cationic groups and with plausible applications as effective broad-spectrum antimicrobial photosensitizers.

An ionic liquid demulsifier with double cationic centers and multiple hydrophobic chains

In this paper, an ionic liquid demulsifier (MDBr-IL) with double cationic centers and multiple hydrophobic chains was synthesized with N,N,N,N,-tetraglycidyl- 4,4-diaminodiphenylmethane as starting materials. The structure of MDBr-IL was characterized by Fourier transform infrared spectrometer (FT-IR) and 1H nuclear magnetic resonance spectrometer (1H NMR). Effect of a few key factors such as concentration, demulsifying time, demulsifying temperature, salinity and pH value on the demulsifying efficiency (DE) was detailly researched in a water-in-crude oil emulsion. When the concentration of MDBr-IL was 500 mg/L, the DE reached 95.24% at 60 °C for 180 min. Also, the DE could increase to 98.64% when the demulsifying temperature was 70 °C. In addition, MDBr-IL had an eminent resistance to acid, alkali and salt. Also, the salinity could further improve the demulsification performance. Interfacial properties and wettability were employed to investigate the possible demulsification mechanism. It demonstrated that MDBr-IL is a viable demulsifier for the separation of oil-water emulsions.

CO2 capture using dicationic ionic liquids (DILs): Molecular dynamics and DFT-IR studies on the role of cations.

Dicationic ionic liquids (DILs) have been shown to be useful as an effective solvent for the absorption of CO2. However, compared to monocationic ionic liquids (MILs), they have been less investigated for this application. Previous studies on MIL-CO2 systems have shown that anions play the main role in tuning CO2 capture, but the partial negative charge on the oxygens of CO2 may interact with cation centers and, especially, for DILs with two charge centers, the role of cations can be significant. Therefore, the current work focuses on how cation symmetry and the length of side chains affect interactions and also the dynamical and structural properties of DIL-CO2 systems using molecular dynamics simulation. In addition, the effect of CO2 on the infrared vibrational spectra of isolated ions and ion triplet (DIL molecules) was studied using density functional theory calculations and the observed red and blue shifts have been interpreted. The results indicated that symmetric cation with longer side chains tend to interact more strongly with CO2 molecules. It seems that increasing the length of the side chains causes more bending of the middle chain, and in addition to increasing the free fraction volume, it weakens the interaction between cations and anions, and as a result more interaction between gas and cation. The results of this work may contribute to the rational molecular design of DILs for CO2 capture, DIL-based gas sensors, etc.

FeII complexes supported by an iminophosphorane ligand: synthesis and reactivity.

The synthesis of iron complexes supported by a mixed phosphine-lutidine-iminophosphorane (PPyNP) ligand was carried out. While bidentate κ2-N,N coordination was observed for FeCl2, pincer coordination modes were adopted at cationic iron centers, either through dechlorination of [LFe(PPyNP)Cl2] (1) or direct coordination of PPyNP to Fe(OTf)2. Reaction with tert-butylisocyanide gave access to the diamagnetic octahedral complex [Fe(PPyNP)(CNtBu)3]X2 (X = OTf (4), Cl (4')). Both 1 and 4 were shown to undergo deprotonation of the phosphinomethyl group, but the resulting complexes were not active for the dehydrogenative coupling of hexan-1-ol. The hydrosilylation of acetophenones was catalyzed at room temperature with 1 mol% of a catalyst generated in situ from cationic PPyNP-supported iron triflate complexes and KHBEt3.

Hydroxide ion-conducting viologen-bakelite organic frameworks for flexible solid-state zinc-air battery applications.

Adaptable polymer-based solid-state electrolytes can be a game-changer toward safe, lightweight flexible batteries. We present a robust Bakelite-type organic polymer covalently decked with viologen, triazine, and phenolic moieties. Its flexible structure with cationic viologen centers incorporates counter-balancing free hydroxide ions into the polymeric framework. By design, the aromatic groups and heteroatoms in the framework can be activated under an applied potential to prompt a push-pull drive, setting off the towing of hydroxide ions via weak electrostatic, van der Waals, and hydrogen-bond interactions. The frontier orbitals from a DFT-modeled structure certify this. The hydroxyl-polymer requires minimal KOH wetting to maintain a humid environment for Grotthuss-type transport. The hydroxide ion conductivity reaches a value of 1.4 × 10-2 S cm-1 at 80 °C and 95% RH, which is retained for over 15 h. We enhanced its practical utility by coating it as a thin solid-state separator-cum-electrolyte on readily available filter paper. The composite exhibits a conductivity of 4.5 × 10-3 S cm-1 at 80 °C and 95% RH. A zinc-air battery (ZAB) constructed using this polymer-coated paper as electrolyte yields a maximum power density of 115 mW cm-2 and high specific capacitance of 435 mA h g-1. The power density recorded for our ZAB is among the best reported for polymer electrolyte-based batteries. Subsequently, the flexible battery fabricated with IISERP-POF11_OH@FilterPaper exhibits an OCV of 1.44 V, and three batteries in series power a demo traffic signal. To underscore the efficiency of hydroxide ion transport through the complex multifunctional backbone of the polymer, we calculated the diffusion coefficient for OH- (Exp: 2.9 × 10-5 cm2 s-1; Comp. 5.2 × 10-6 cm2 s-1) using electrochemical methods and MD simulations. Climbing-edge NEB calculations reveal a large energy barrier of 2.11 eV for Zn2+ to penetrate the polymer and identify hydroxide ions within the polymer, suggesting no undesirable Zn2+ crossover. Our findings assert the readily accessible C-C-linked cationic polymer's capacity as a solid-state electrolyte for ZABs and any anion-conducting membrane.

Conjugative Stabilization versus Anchimeric Assistance in Carbocations.

In this study, an old concept of anchimeric assistance is viewed from a different angle. Primary cations with two different heteroatomic substituents in the α-position to the cationic carbon atom CHXY−CH2+ (X, Y = Me2N, MeO, Me3Si, Me2P, MeS, MeS, Br) can be stabilized by the migration of either the X or Y group to the cation center. In each case, the migration can be either complete, resulting in the transfer of the migrating group to the adjacent carbon atom and the formation of a secondary carbocation stabilized by the remaining heteroatom, or incomplete, leading to an anchimerically assisted iranium ion. For all combinations of the above groups, these transformations have been studied by theoretical analysis at the MP2/aug-cc-pVTZ level and were shown to occur depending on the ability of anchimeric assistance by X and Y, as well as the conformation of the starting primary carbocation. In the conformers of α-amino cations with the p-orbital, C−N bond and the nitrogen lone pair in one plane, the Me2N group migrates to the cationic center to give aziranium ions. Otherwise, the second heteroatom is shifted to give iminium ions, without or with very slight anchimeric assistance. In the α-methoxy cations, the MeO group can be shifted to the cationic center to give the O-anchimerically assisted ions as local minima, the global minima being the ions anchimerically assisted by another heteroatom. The electropositive silicon tends to migrate towards the cationic center, but with the formation of a π-complex of the Me3Si cation with the C=C bond rather than a Si-anchimerically assisted cation. The phosphorus atom can either fully migrate to the cationic center (X = P, Y = S, Se) or form anchimerically stabilized phosphiranium ions (X = P, Y = O, Si, Br). The order of the anchimeric assistance for the heaviest atoms decreases in the order Se >> S > Br.

Hybrid copper halide material with perovskite like structure with tetrahedral units; synthesis, characterization and optical properties

Many attempts have been made to substitute lead as the metal cation in perovskite materials but, at the same time, retain its favorable optical and electrical properties. Copper is a naturally abundant metal as well as more environmentally friendly than Pb, thus, can be used as the metal cation in regards to possible substitution candidate perovskites. Herein we report the synthesis and optoelectronic properties of two novel compounds with perovskite-like structure and Cu as the central cation. The analysis includes Powder XRD data and a Density Functional Theory (DFT) study for a thorough understanding of their structure. By Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Vibronic studies (FTIR, Raman), Nuclear Magnetic Resonance (NMR) and Mass spectra we fully explain the chemical analysis of the final material. Complete analysis of their optoelectronic properties is explained and presented with UV–vis measurements. Furthermore, we correlate their properties with their structure with Raman spectroscopy but also via computational theoretical DFT studies.

Polymeric ionic liquids and ionic liquids of ionen type

A set of new experimental data was obtained regarding the influence of the structure of dimer ionene ionic liquids on their physical and chemical properties, which is the basis of the methodology for the synthesis of polymer ionene ionic liquids. It was established that the introduction of allyl and -hydroxyethyl groups into the quaternary nitrogen atom, the presence of a dibenzyl fragment at the cationic center and alkylaromatic radicals permit obtaining polymeric ionic liquids of the ionene type with a high level of ionic conductivity at a low glass transition temperature. Newly synthesized polymeric ionic liquids and ionene ionic liquids based on 1,2-epoxy-4,7-dioxononen-8 and tetrahydro-1,4-oxazine derivatives with an ionic conductivity of ~10–1–10–4 S cm–1 with glass transition temperature range of –1400С to –160С exhibited five to six orders of magnitude higher ionic conductivity as compared with known analogues. Recommendations for solving the problem of developing polymeric ionic liquids and ionene ionic liquids exhibiting high ionic conductivity while maintaining their liquid state in a wide temperature range have been developed.

Kinetically‐Locked Metallomacrocycle for Host‐Guest Chemistry with Bulky Anions

AbstractAs a robust and large molecular receptor, a kinetically‐locked trinuclear Co(III) macrocycle was synthesized with bis(β‐diketone) ligands having large π‐panels of 9,10‐diphenylanthracene moieties via a combination of Co(II)‐assisted self‐assembly and subsequent oxidation of the metal centers. The X‐ray structure revealed that the macrocycle had a discrete nanocavity of more than 300 Å3, which was surrounded by three anthracenyl panels in the middle. As the macrocycle has three cationic centres on each metal ion and a large cavity, it acts as a guest receptor for sodium tetraphenylborate. The binding constant was estimated to be 4.0×10−2 M−1 from 1H NMR titration experiments, whereas no interaction was observed between the macrocycle and potassium 1‐adamantanecarboxylate.

Explaining the High Catalytic Activity in Bis(indenyl)methyl Zirconium Cation Using Combined EDA-NOCV/QTAIM Approach.

The main purpose of this study is to elucidate some discrepancies already observed in the catalytic activity values of some zirconocene methyl cations. The EDA-NOCV scheme was employed for a theoretical description of the interactions between an ethylene molecule and five catalysts of zirconocene methyl cation. The nature of the chemical interactions has been elucidated through the QTAIM topological analysis. The steric hindrance due to the ligands was evaluated qualitatively by means of an IRI-based analysis and quantitively through Fisher information. The findings prove that the indenyl ligand seems to favor the orbital interaction between the ethylene molecule and the metal centre of zirconocene methyl cation. Both electrostatic and orbital contributions play a crucial role in stabilising the studied complexes. Based on the NOCV deformation density contributions, the strongest orbital interaction is reached with the bis(indenyl)methyl zirconium cation, which is the only one exhibiting covalent interactions. Especially, the strong contribution of π-back donation (occurring from the occupied orbitals of the zirconium atom to the π* anti-bonding orbital of ethylene) may be a key to understand why this catalyst has a higher polymerisation yield than the other studied catalysts. This work suggests a perspective for predicting values of catalytic activity when theoretically designing novel catalysts of zirconocene type.

Effect of different cation on PVA/IL solid electrolyte for electrochemical supercapacitor

Poly (room temperature ionic liquids-RTIL) with the different cationic centre have been explored for high operating voltage supercapacitor application. Ionic liquids with different cations (phosphonium, ammonium, and sulfonium) based transparent gel electrolytes were formulated by adopting polyvinyl alcohol (PVA) which could assemble supercapacitor device. To establish the impact of changing the cationic centre in conduction mechanism and molecular dynamics broadband dielectric spectroscopy was used. The dielectric results show the ion dynamics in the whole frequency range has a dependency on the cationic centre. The supercapacitor fabricated with the resultant PVA/ILs and activated carbon electrode were tested with cyclic voltammetry, galvanostatic charge–discharge curves, and impedance spectroscopy. The electrochemical results return a step towards to the chemical and physical properties of an IL can be made the system by changing their cations in a suitable operation. Among the preferred samples, the highest conductivity (1.5 × 10−3 S/cm), specific capacitance (400 F/g) and energy density (56.25 Wh/Kg) were obtained for sulfonium cationic core RTIL polymer electrolyte.

Electrochemical properties and electrocatalytic activity of novel iron and manganese tribenzopyrazinoporphyrazine complexes

Two novel tribenzopyrazinoporphyrazines with peripheral 4-methoxyphenyl substituents were synthesized to evaluate the effect of the centrally coordinated transition metal cation (4 – Mn3+ or 5 – Fe3+) on their electrochemical properties. The obtained complexes were characterized by UV–vis spectrophotometry, mass spectrometry, and NMR techniques. The electrochemical measurements, involving the CV and DPV voltammetry, were performed and revealed four or six redox processes in researched compounds with one related to the reduction of the central metal cation. The HOMO-LUMO electrochemical band gaps of the synthesized porphyrazines were estimated, and the obtained values were in a good agreement with the optical band gaps calculated from UV–vis. The empirical studies were accompanied by the theoretical ones including linear response time-dependent density function theory (LR TD-DFT) calculations. In both porphyrazines, the HOMOs presented similar shapes. The electrochemical sensing properties of porphyrazines were studied after their deposition on the surface of multi-walled carbon nanotubes (MWCNT). The obtained hybrid materials were embedded on glassy carbon electrodes (GC) using the drop and dry technique. The functionalized electrodes were studied for electrocatalytic reduction of diclofenac sodium salt revealing the superior performance of the GC/MWCNT/5 electrode.

Fluorescence Quenching of Carboxy-Substituted Phthalocyanines Conjugated with Nanoparticles under High Stoichiometric Ratios

Background: The search of the approaches towards a photosensitizer’s conjugation with multifunctional nanoparticles is an important step in the development of photodynamic therapy techniques. Association of photosensitizer molecules with nanoparticles that perform the delivery function can lead to a change in the functional state of the photosensitizer. Methods: We studied the effects observed upon incorporation of octa- and hexadeca-carboxyphthalocyanines of zinc(II) and aluminum(III) (Pcs) into the polymer shell of nanoparticles with a semiconductor CdSe/CdS/ZnS core with various spectral and optical methods. Results: First, the interaction of Pc with the polymer shell leads to a change in the spectral properties of Pc; the effect strongly depends on the structure of the Pc molecule (number of carboxyl groups as well as the nature of the central cation in the macrocycle). Secondly, upon incorporation of several Pc molecules, concentration effects become significant, leading to Pc aggregation and/or nonradiative energy transfer between neighboring Pc molecules within a single nanoparticle. Conclusions: These processes lead to the decrease of a number of the Pc molecules in an excited state. Such effects should be taken into account during the development of multifunctional platforms for the delivery of photosensitizers, including the use of nanoparticles as enhancers of photosensitizer activity by energy transfer.

Peripheral Groups of Dicationic Pyrazinoporphyrins Regulate Lipid Membrane Binding.

Photodynamic therapy (PDT) is a widely used technique for skin cancer treatment and antimicrobial therapy. An improvement in PDT efficiency requires not only an increase in quantum yield of photosensitizer (PS) molecules but also their applicability for biological systems. Recently, we demonstrated that the activity of porphyrin-based PSs in the lipid membrane environment depends on the nature of the cation in the macrocycle due to its interactions with the lipid phosphate moiety, as well as the orientation of the PS molecules inside the membrane. Here, we report the synthesis, membrane binding properties and photodynamic efficiency of novel dicationic free-base, Ni(II) and Zn(II) pyrazinoporphyrins with terminal tetraalkylammonium units (2H-1, Ni-1 and Zn-1), to show the possibility to enhance the membrane binding of PS molecules, regardless of the central cation. All of these substances adsorb at the lipid membrane, while free-base and Zn(II) porphyrins actively generate singlet oxygen (SO) in the membranes. Thus, this study reveals a new way to tune the PDT activity of PSs in biological membranes through designing the structure of the peripheral groups in the macrocyclic photosensitizer.

Surface acid properties of Nb2O5–P2O5–SiO2 gel-derived catalysts

Amorphous catalytic materials belonging to the Nb2O5–P2O5–SiO2 system were prepared through an original sustainable sol-gel procedure, and characterized by surface area, porosity and acidity measurements. Their acid properties have been investigated by FT-IR spectroscopy of adsorbed pyridine, ammonia titration and TPR, as well as by titration with 2-phenylethylamine from organic solution. They present Lewis acidity attributed to niobium surface cationic centers, and Brønsted acidity sufficiently strong to protonate pyridine. The total acidity depends on the niobium content. The conversion of ethanol was investigated by vapor phase Temperature Programmed Reaction, steady-state catalytic experiments and static In Situ FTIR experiments. The samples are active in converting ethanol to ethylene with 100% selectivity at low conversion (523–573 K), but also produce acetaldehyde by dehydrogenation at higher temperature and conversion. They show an unusually poor activity for the production of diethylether also at low ethanol conversion. Ethoxy groups act as reaction surface intermediates.

Two isomers Ba5Mg4C54O48H114 and Pb5Mg4C54O48H114

Abstract There are reported two related structures of Ba5Mg4C54O48H114 (dodeca(aqua-6κ 3O,7κ 3O,8κ 3O,9κ 3O)-tris(μ2-propanoato-1:6κ 2O,1κO′)-tris(μ-propanoato-2:7κ 2O,2κO′-tris(μ-propanoato-3:8κ 2O,3κO′)-tris(μ-propanoato-4:9κ 2O,4κO′)-hexakis(μ3-propanoato-1:5κ 2O,2:5κ 2O′;1:5κ 2O,3:5κ 2O′;1:5κ 2O,4:5κ 2O′;2:5κ 2O,3:5κ 2O′;2:5κ 2O,4:5κ 2O′;3:5κ 2O,4:5κ 2O′)-pentabarium tetramagnesium), (I), and Pb5Mg4C54O48H114 (dodeca(aqua-1κ 3O,2κ 3O,3κ 3O,4κ 3O)-hexakis(μ3-propanoato-1:5κ 2O,2:5κ 2O′;1:5κ 2O,3:5κ 2O′;1:5 κ 2O,4:5κ 2O′;2:5κ 2O,3:5κ 2O′;2:5κ 2O,4:5κ 2O′;3:5κ 2O,4:5κ 2O′)tetramagnesium lead(II) tris(propanoato-κ 2O,O′)plumbate(II)), (II). The title structures are compositional isomers which crystallize in the same space group type. The structure of (I) comprises molecules with symmetry 4 ‾ 3 m $\overline{4}3m$ . The structure (II) comprises the complex cation {Pb(C3H5O2)6[Mg(H2O)3]4}4+ with the symmetry 4 ‾ 3 m $\overline{4}3m$ and four anions [tris(propanoato-κ 2O,O′)plumbate(II)]−, [Pb(C3H5O2)3]− , with 3m symmetry. The central cations Ba12+ and Pb12+ in (I) and in the cation {Pb(C3H5O2)6[Mg(H2O)3]4}4+ of the structure (II), respectively, have similar structural features which are comparable to the environment of the Ba2+ cation in BaCa2(C3H5O2)6 [Stadnicka, K. & Glazer, A. M. (1980). Acta Cryst. B36, 2977–2985]. The molecules in (I) and the ions in (II) are interconnected by Owater‒H⋯Opropanoate hydrogen bonds of a moderate strength. The ethyl chains are disordered which is common in propanoates. However, there are unprecedented features in the title structures: 1) The central atom Pb12+ is the first known example of a Pb2+ cation which is surrounded by six carboxylates in a bidentate bridging mode, i.e. by 12 oxygens. 2) The anion [tris(propanoato-κ 2O,O′)plumbate(II)]− has a constitution with unusually prominent stereochemical activity of the 6s 2 electron pair of the cation Pb2+ completing the coordination to the tetrahedral one. Thus, its formula can be expressed as [Pb[ψ−4t](C3H5O2)3]−. 3) In both title structures, there are propanoate molecules with disordered carboxylate oxygens.

Entropy of electrolytes with off-centre charge cations. Monte Carlo studies

Monte Carlo techniques including Inverse Grand Canonical Monte Carlo simulations are utilized to calculate the entropy of a restricted primitive model electrolyte with the caveat that the cation charge centre is displaced from the geographical centre of the cation sphere towards the surface of the sphere. Calculations have been performed for symmetric valency (1:1) and asymmetric valency (2:1) electrolytes at 298.15 K for a range of electrolyte concentrations. The cation charge centre displacement accompanied by an increase of temperature leads to an increase of entropy. For the 2:1 valency system the entropy as a function of the square root of concentration reveals a broad inflexion region that separates the domains of deformation due to the electrostatic and steric interactions. When the central ion is an anion, and the charge centres of the surrounding cations are oriented towards the anion then the electrostatic interactions are stronger than in the standard restricted primitive model and the entropy decreases, while a central cation deforms the ionic atmosphere surrounding it and the entropy increases. In the low concentration regime good agreement is seen between the results from the Debye-Hückel limiting law and the corresponding simulations.

Cross-metathesis of biomass to olefins: Molecular catalysis bridging the gap between fossil and bio-energy

Terminal olefins are important building blocks for the industry of biofuels, oligomers, and lubricants production. The industrial processes for production of olefins involving oligomerization of ethylene or cracking of petrochemical waxes have several flaws including low yield and high cost in product separation. Cross - metathesis of bio - derived unsaturated fatty esters and olefins with ethylene (ethenolysis), allows the conversion of sustainable waste biomass to various renewable olefins with much safer, less toxic, sustainable, and zero-CO 2 emission processes. To our best knowledge, however, a comprehensive summary of key advances in this field (since 2017) is yet to be available, particularly on molecular features of homogeneous and heterogeneous catalysts. This paper presents a critical review on molecular structures of metal complex and oxide catalysts for ethenolysis of olefins and oleochemicals. The influence of cationic centers, coordination conditions, nature of ligands, operating conditions on catalyst performances will be systematically discussed along with relevant reaction mechanism. The key challenges for rational design of coordinated cationic hybrids have been summarized, which will provide insights to technological advancement of large - scale production of oleochemical - derived olefins.

Solution-processable copper(I) iodide-based inorganic-organic hybrid semiconductors composed of both coordinate and ionic bonds

Three new one-dimensional (1D) All-In-One (AIO) type CuI-based hybrid semiconductors with both dative and ionic bonds between the inorganic and organic components have been successfully designed and synthesized by using the ligands containing both cationic center and coordination available sites. Structural analysis confirms that all compounds share the same formula of Cu4I6(L)2 (L ​= ​ligand) and are composed of 1D-Cu4I62− anionic chains that coordinate to cationic ligands. These materials demonstrate high stability towards heat and moisture and excellent solution processability due to their unique bonding nature. They emit low energy light ranging from green to orange color (530–590 ​nm). The origin and mechanism of their emissions were studied by both experimental and theoretical methods. More importantly, all compounds can be easily fabricated into films by solution process, a desired but rare feature for most of CuI-based hybrids built of extended networks.