Sustainable catalysts for efficient triazole synthesis: an immobilized triazine-based copper-NNN pincer complex on TiO2

The multistep synthesis of a hybrid material based on a TiO2 core with an immobilized triazine-based copper(II)-NNN pincer complex is reported. The formation of the material was confirmed by FT-IR spectroscopy and elemental and thermogravimetric analyses, and the loading by copper ions was quantified by ICP/OES analysis. The properties of the hybrid material were further investigated by X-ray photoelectron spectroscopy (XPS), contiuous wave electron spin resonance (CW-ESR), UV-vis spectroscopy, and argon sorption. Efficient and regioselective synthesis of 1,4-disubstituted 1,2,3-triazoles was achieved by employing the hybrid material as a catalyst in a mixture of H2O/EtOH as a green solvent with excellent catalytic activity with a TOF up to 495 h-1 at 50 °C. The reusability of the prepared hybrid material in the catalytic reaction was possible over five consecutive runs without significant loss of catalytic activity. The described method represents an effective way to ensure sustainable use of pincer complexes in catalytic systems by immobilizing them on solid supports, resulting in a hybrid organic-inorganic catalyst platform.

Improving the performance of an anionic MOF by counter cation replacement as electrode material in a full cell setup of a potassium ion capacitor

Potassium-based energy storage devices are attracting increasing attention as an alternative to lithium and sodium systems. In addition, metal-organic frameworks (MOFs) can be considered as promising electrode materials for this type of device due to their advantageous properties. Herein, the anionic MOF JUMP-1 and its analog with pre-loading of potassium cations, namely JUMP-1(K), were synthesized and characterized. The anionic framework of JUMP-1 is found to be extremely stable towards the exchange of the dimethylammonium cations by potassium ions. These MOFs were tested in composite electrodes in combination with conventional organic electrolytes as anode materials in a potassium-based system, including the full cell assembly of a potassium ion capacitor (KIC). The results show the significant improvement in capacity between the pristine JUMP-1 and the potassium-exchanged analog JUMP-1(K) as electrode materials. KICs containing JUMP-1(K) coupled with activated carbon (AC) display a promising stability over 4000 cycles. According to the results from these studies, the composite MOF electrode with the potassium-exchange analog JUMP-1(K) presents a promising approach, for which the electrochemical performance compared to the pristine anionic MOF is significantly enhanced.

Enhancing Capacity and Stability of Anionic MOFs as Electrode Material by Cation Exchange

In this study we report on the characterization and use of the anionic metal-organic framework (MOF) JUMP-1, [(Me₂NH₂)₂[Co₃(ntb)₂(bdc)]]_n, alongside with its alkali-metal ion-exchanged analogs JUMP-1(Li) and JUMP-1(Na), as electrode materials for lithium and sodium batteries. Composite electrodes containing these anionic-MOFs were prepared and tested in 1 M lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) in propylene carbonate (PC) and/or 1 M sodium TFSI (NaTFSI) in PC. We showed that the ion-exchanged materials JUMP-1(Li) and JUMP-1(Na) display higher capacities in comparison with the original as-prepared compound JUMP-1 (490 mA∙h∙g⁻¹ vs. 164 mA∙h∙g⁻¹ and 83 mA∙h∙g⁻¹ vs. 73 mA∙h∙g⁻¹ in Li and Na based electrolytes, respectively). Additionally, we showed that the stability of the electrodes containing the ion-exchanged materials is higher than that of JUMP-1, suggesting a form of chemical pre-alkalation works to stabilize them prior to cycling. The results of these studies indicate that the use of designed anionic-MOFs represents a promising strategy for the realization of high performance electrodes suitable for energy storage devices.

Evaluation of segmental mandibular resection without microvascular reconstruction in patients affected by medication-related osteonecrosis of the jaw: a systematic review

Medication-related osteonecrosis of the jaw (MRONJ) is a severe condition that affects the jaw in patients exposed to specific drugs. More often it has been described in association with bisphosphonates (BP), but nowadays it has been observed with the use of other medications, such as denosumab (a RANK ligand inhibitor and monoclonal antibody agent) and antiangiogenic drugs. Managing the condition has unfortunately proven difficult and still remains a major challenge for clinicians and surgeons. The aim of this systematic review was to identify and analyse the evidence on mandibular segmental resection in patients with advanced MRONJ. A multi-database (PubMed, MEDLINE, EMBASE, CINAHL, and Cochrane Central Register of Controlled Trials) systematic search was performed. Any type of study on human patients treated with antiresorptive and antiangiogenic drugs was considered. The primary aim was to understand the success of mandibular segmental resection in the short, medium, and long term, and to understand its effects before, during, and after the operation. The search yielded 11 studies that were eligible for analysis with a total of 67 patients. Of the 11 studies, seven reported no complications, and overall, postoperative complications were seen in 16 cases. Recurrence of osteonecrosis was reported in one study. The most common postoperative complication was removal of hardware (n = 11). The mean (SD) follow-up time for eight studies was 35.57 (17.73) months. According to the limited data available in the literature, mandibular segmental resection is a viable treatment that has been used successfully in patients with various stages of MRONJ. The data show a relatively high percentage of recurrence. Additional data based on a larger cohort of patients or case-control studies are necessary to justify routine use of this type of intervention in patients affected by the condition.

The role of illicit drugs in developing medication-related osteonecrosis (MRONJ): a systematic review

Medication-related osteonecrosis of the jaw (MRONJ) is a challenging condition to treat. It has primarily been associated with anti-resorptive and anti-angiogenic drugs, which are increasingly being used to prevent adverse skeletally-related complications in patients with cancer and bone pathologies. Although these medications have been proven to cause osteonecrosis of the jaws (ONJ) there are also a number of other drugs that could potentially cause this condition. The aim of this systematic review is to ascertain whether there is an associated risk of osteonecrosis of the jaw (ONJ) in recreational drug users (RDU). Three authors independently searched PubMed, MEDLINE, EMBASE, CINAHL and the Cochrane Central Register of Controlled Trials for published reports of osteonecrosis of the jaw (ONJ) in recreational drug users (RDU) or illicit drug users (IDU) who had no history of treatment with anti-angiogenic or anti-resorptive agents. Only 30 studies were eligible for analysis, and all were independently assessed for risk of bias. There was a total of 101 patients with ONJ attributed solely to illicit drug consumption. The most common site of ONJ was the maxilla (n=54). The most common illicit drug related to ONJ was desmorphine, known as 'Krokodil', this was followed by cocaine, methamphetamine, anabolic steroids, and hydrocodone/acetaminophen. In 52 of the cases, the ONJ resolved following treatment, however, eight showed a recurrence. Although all the studies were judged to be at a high risk of bias, the limited data suggest that some patients are at risk of developing ONJ as a result of illicit drug usage. Studies of higher quality are needed to establish the relative risk of ONJ in this patient group.

Osteonecrosis and osteomyelitis of the jaw associated with tumour necrosis factor-alpha (TNF-α) inhibitors: a systematic review

Tumour necrosis factor-α (TNF-α) inhibitors are increasingly being used as immunomodulators to manage inflammatory conditions such as rheumatoid arthritis and Crohn's disease. Reported serious side effects include an increased incidence of lymphoma and greater susceptibility to infections such as tuberculosis. The aim of this systematic review was to find out whether there is an associated risk of medication-related osteonecrosis of the jaw (MRONJ). Three authors independently searched PubMed, MEDLINE, EMBASE, CINAHL and the Cochrane Central Register of Controlled Trials for published reports of oral osteonecrosis (ONJ) or osteomyelitis (OM) in patients who took anti TNF-α drugs and had no history of antiangiogenic agents or antiresorptive treatment. All types of studies on humans treated with TNF-α inhibitors were considered. Only six were eligible for analysis, and all were independently assessed for risk of bias. They included six patients with ONJ or OM that was attributed solely to TNF-α inhibitors. The most common site of ONJ was the posterior mandible (n=5). The mean (SD) duration of anti-TNF-α treatment before the development of bony lesions was 62.5 (47.4) months. Invasive surgery was reported as a precipitating factor in five cases, and the ONJ/OM resolved with conservative management in five. Although all the studies were judged to be at high risk of bias, the limited data suggest that some patients will potentially develop ONJ/OM as a result of treatment with TNF-α inhibitors. Studies of higher quality are now needed to establish the relative risk of MRONJ in patients who take them.

Metal-Bonded Redox-Active Triarylamines and Their Interactions: Synthesis, Structure, and Redox Properties of Paddle-Wheel Copper Complexes

Four new triphenylamine ligands with different substituents in the para position and their corresponding copper(II) complexes are reported. This study includes their structural, spectroscopic, magnetic, and electrochemical properties. The complexes possess a dinuclear copper(II) paddle‐wheel core, a building unit that is also common in metal‐organic frameworks. Electrochemical measurements demonstrate that the triphenylamine ligands and the corresponding complexes are susceptible to oxidation, resulting in the formation of stable radical cations. The square‐wave voltammograms observed for the complexes are similar to those of the ligands, except for a slight shift in potential. Square‐wave voltammetry data show that, in the complexes, these oxidations can be described as individual one‐electron processes centered on the coordinated ligands. Spectroelectrochemistry reveals that, during the oxidation of the complexes, no difference can be detected for the spectra of successively oxidized species. For the absorption bands of the oxidized species of the ligands and complexes, only a slight shift is observed. ESR spectra for the chemically oxidized complexes indicate ligand‐centered radicals. The copper ions of the paddle‐wheel core are strongly antiferromagnetic coupled. DFT calculations for the fully oxidized complexes indicate a very weak ferromagnetic coupling between the copper ions and the ligand radicals, whereas a very weak antiferromagnetic coupling is found among the ligand radicals.

Front Cover: Metal‐Bonded Redox‐Active Triarylamines and Their Interactions: Synthesis, Structure, and Redox Properties of Paddle‐Wheel Copper Complexes (ChemistryOpen 3/2019)

The Front Cover shows a scene illustrating the need to investigate the properties of building blocks for complex systems to enable the basic design of new functional materials. It shows a model of the investigated paddle‐wheel complexes with copper‐bonded triphenylamines. Both paddle‐wheel units and triarylamine linkers are basic constituents found in several frameworks such as the networks shown in the image. More information can be found in the Full Paper by O. Akintola et al. on page 266 in Issue 3, 2019 (DOI: 10.1002/open.201800243).

Metal-Bonded Redox-Active Triarylamines and Their Interactions: Synthesis, Structure, and Redox Properties of Paddle-Wheel Copper Complexes

Invited for this month's cover picture is the group of Professor Winfried Plass at the Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University, Jena (Germany). The cover picture shows a scene illustrating the need to investigate the properties of building blocks for complex systems to enable the basic design of new functional materials. The utilized triphenylamine ligands are constituting parts of the currently investigated "Jena University Magnetic Polymer" (JUMP) series. Read the full text of their Full Paper at 10.1002/open.201800243.

Probing the chirality of oxidovanadium(v) centers in complexes with tridentate sugar Schiff-base ligands: solid-state and solution behavior

Configurations of oxidovanadium centers in diastereomeric complexes with chiral sugar ligands are assigned and in the solid state triggered by the coordination number at the vanadium center through the steric requirements of the chelate ligand.

Organic co-crystals of 1,3-bis(4-pyridyl)azulene with a series of hydrogen-bond donors

1,3-Bis(4-pyridyl)azulene has been employed as a hydrogen bond acceptor to construct two-component organic cocrystals.

Solvent-dependent selective cation exchange in anionic frameworks based on cobalt(ii) and triphenylamine linkers: reactor-dependent synthesis and sorption properties

Two anionic cobalt(ii) MOFs were obtained dependent on the reactor design and show a solvent-dependent cation exchange leading to a remarkable increase in the surface area of post-synthetic modified materials.

Specific Surface versus Electrochemically Active Area of the Carbon/Polypyrrole Capacitor: Correlation of Ion Dynamics Studied by an Electrochemical Quartz Crystal Microbalance with BET Surface

Carbon/polypyrrole (PPy) composites are promising electrode materials for energy storage applications such as lightweight capacitors. Although these materials are composed of relatively inexpensive components, there is a gap of knowledge regarding the correlation between surface, porosity, ion exchange dynamics, and the interplay of the double layer capacitance and pseudocapacitance. In this work we evaluate the specific surface area analyzed by the BET method and the area accessible for ions using electrochemical quartz-crystal microbalance (EQCM) for SWCNT/PPy and carbon black Vulcan XC72-R/PPy composites. The study revealed that the polymer has significant influence on the pore size of the composites. Although the BET surface is low for the polypyrrole, the electrode mass change and thus the electrochemical area are large for the polymer-containing electrodes. This indicates that multiple redox active centers in the charged polymer chain are good ion scavengers. Also, for the composite electrodes, the effective charge storage occurs at the polypyrrole-carbon junctions, which are easy to design/multiply by a proper carbon-to-polymer weight ratio. The specific BET surface and electrochemically accessible surface area are both important parameters in calculation of the electrode capacitance. SWCNTs/PPy showed the highest capacitances normalized to the BET and electrochemical surface as compared to the polymer-carbon black. TEM imaging revealed very homogeneous distribution of the nanosized polymer particles onto the CNTs, which facilitates the synergistic effect of the double layer capacitance (CNTs) and pseudocapacitance (polymer). The trend in the electrode mass change in correlation with the capacitance suggest additional effects such as a solvent co-insertion into the polymer and the contribution of the charge associated with the redox activity of oxygen-containing functional groups on the carbon surface.

A facile, green and efficient surfactant-free method for synthesis of aluminum nanooxides with an extraordinary high surface area

Nano boehmite with unprecedented high surface area and pore volume (802 m² g⁻¹, 2.35 cm³ g⁻¹) was prepared using a facile, green and efficient surfactant-free synthesis method.

Facile synthesis of highly thermally stable nanoporous γ-aluminas from aluminum alkoxide precursors

The effects of aluminum alkoxide single source precursors on the sol–gel synthesis of highly thermally stable nanostructured alumina by nonionic triblock copolymer P123 were investigated.

Experience of sexual coercion among adolescents in Ibadan, Nigeria

This study surveyed 1,025 adolescent students and apprentices in Ibadan, Nigeria, to document their sexual behaviour and experience of sexual coercion including verbal threats, unwanted touch, unwanted kiss, assault, deception, drugging, attempted rape, and rape. Sixty five per cent of male and 48% of female apprentices were sexually experienced, compared to 32% of male and 24% of female students. More males than females reported sex with multiple partners and contact with a sex worker while females had exchanged sex for money and gifts. Fifty five per cent of all the subjects had been victims of at least one type of sexual coercion, the commonest being unwanted kiss and touch of breasts (47%). Although both males and females were victims of coercion, females were disproportionately affected--68% of female students and 70% of apprentices had experienced one coercive behaviour, compared to 42% of male students and 40% of apprentices. Female apprentices fared worst, with 19% of them raped. The main perpetrators of the coercion were persons well known to the victims including neighbours, peers and boy/girlfriends. We recommend multiple intervention programs including skills training for young persons, sensitisation workshop for training health workers, and media advocacy for the public to challenge stereotypes that favour sexual coercion of adolescents.

Perceptions of sexual coercion: learning from young people in Ibadan, Nigeria

This study explored the problem of sexual coercion from the perspectives of 77 young people aged 14-21 in Ibadan, Nigeria, the behaviours they perceive to be sexually coercive and the contexts in which these occur through four narrative workshops. Participants were drawn from two secondary schools and 15 apprentice workshops. All four groups identified similar coercive behaviours and developed narratives of the events that typically lead up to them. Behaviours included rape, unwanted touching, incest, assault, verbal abuse, threats, unwanted kissing; forced exposure to pornographic films, use of drugs for sedation and traditional charms for seduction, and insistence on abortion if unwanted pregnancy occurs. Men were typically the perpetrators and young women the victims. Perpetrators included acquaintances, boyfriends, neighbours, parents and relatives. All the narratives revealed the inability of young people to communicate effectively with each other and resolve differences. The results suggest the need for life-skills training that facilitates communication, seeks to redress gender power imbalances, teaches alternatives to coercion as a means of resolving conflict over sexual relations and respect for sexual and reproductive rights, and provides victims with information on appropriate services, support and referral.