To meet current market demands as well as emerging environmental concerns there is a need to develop less polluting battery technologies.

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International audience1,6-Bis(1-imidazolyl)-2,4-hexadiyne (1) and1,6-bis(1-benzimidazolyl)-2,4-hexadiyne (5) have beenpreparedby a novel method that consists in refluxing excess imidazole and benzimidazole with 2,4-hexadiyne-1,6-diol bis(p-toluenesulfonate),pTS (3). This procedure is a viable alternative to the widely used Hay coupling protocol in case the target diyne possesses substituents capable of deactivating the copper catalyst by complexation. Diyne1crystallizes as a hydrate,1?H2O(2). For this compound, water is essential toachieve a crystalline material, and attempts to obtain crystals without included solvent were unsuccessful. In the structure of2, the organic fragments organize around the water molecule and interact with it through a dense network of hydrogen bonds. The CMC-CMC moieties are not oriented suitably for topochemical polymerization, and when trying to alter the organizationof the crystal by heating so as to induce polymerization, water is lost in an abrupt fashion that leads to instantaneous decomposition into polyaromatic-like species. Similar results were observed when water was removedin vacuo at room temperature. The benzimidazole-containing compound can be crystallized with water molecules (4)orwithout(5). X-ray crystallography shows that the structure of 5is organized by numerous C-H...N, C-H...p,andimidazolyl...imidazolyl p-p interactions. The diacetylene molecules almost have the right arrangement for topochemical polymerization, withpossibly reactingCMC-CMC fragments not beingparallel, a rare situation indiacetylene chemistry. Yet, experiments showthat topochemical polymerizationdoes not occur. Incorporationofwater in the lattice of5leads toa solvate that is topochemically reactive. Unlike2, however, water molecules in 4are not isolated but are organized as ribbons. Spectroscopic characterization of the polymer of4indicates that it is a blue phase polymer, with water coordinated to it. This study shows that it is possible to use water, and more generally solvent molecules, to transform a nonreactive diacetylene into a reactive one, even though this approach is less predictable than the cocrystal approach developed by Fowler, Lauher, and Goroff. The solvate approach is simple to implement, quite versatile because of the large rangeof solvents available, andonedoes not face theproblemof having to remove the host in case one needs to recover the polymer. Previous studies describing a similar approach are scarce

A novel strategy for the preparation of nitrogen-doped carbon is presented that is based on the use of azole-functionalized diacetylenic precursors (imidazole and benzimidazole). As demonstrated by thermal analyses (TGA, DSC) and spectroscopic measurements (IR, 13 C solid-state NMR), these diacetylenic molecules undergo exothermic polyaromatization at low temperature. This process is independent of the intrinsic ability of the diacetylenes to undergo solid-state topochemical polymerization. At 800 C, graphite-like structures incorporating nitrogen are obtained, as proven by XPS measurements. The nitrogen contents of the residues resulting from thermolysis at 800 C are fairly high, 7.4 and 8.4 wt%, and these percentages amount to about 4 wt% at 1100 C. This study also shows that mixing these diacetylenes with small amounts of FeCl 2 prior to pyrolysis at 800 C leads to porous carbon materials with relatively high surface areas, 253 and 281 m 2 g À1 . TEM photographs indicate that these porous carbon materials form graphitic nanostructures. Polydiacetylenes also decompose into graphite-like materials, and the degree of graphitization of these materials and their nitrogen contents are comparable to those of the residues obtained by pyrolysis of the diacetylene monomers. Thus, low molecular weight diacetylenic monomers are effective precursors to access graphite-like materials, and this process does not require the prior preparation of a polymer.

Imidazolium- and benzimidazolium-substituted diacetylenes with bromide or nitrogen-rich dicyanamide and tricyanomethanide anions were synthesized and used as precursors for the preparation of N-doped carbon materials. On pyrolysis under argon at 800 °C both halide precursors afforded graphite-like structures with nitrogen contents of about 8.5%. When the dicyanamide and tricyanomethanide precursors were thermolyzed at the same temperature, graphite-like structures were obtained that exhibit nitrogen contents in the range 17-20 wt%; thereby, the benefit of associating a polymerizing cation with a polymerizing anion in a single precursor was demonstrated. On pyrolysis at 1100 °C the nitrogen contents of the latter pyrolysates remain high (ca. 6 wt%). Adsorption measurements with krypton at 77 K indicated that the materials are nonporous. The highest electrical conductivity was observed for a pyrolysate with one of the lowest nitrogen contents, which also has the highest degree of graphitization. Thus, the quest for N-rich carbons with high electrical conductivities should include both maximization of the nitrogen content and optimization of the degree of graphitization. Crystallographic investigation of the precursors and spectroscopic characterization of the pyrolysates prepared by heating at 220 °C indicate that construction of the final carbon framework does not involve the intermediate formation of a polydiacetylene.

Solvothermal reaction in N,N-dimethylformamide (DMF) between 1,6-bis(1-imidazolyl)-2,4-hexadiyne monohydrate (L1⋅H O), isophthalic acid (H L2), and Zn(NO ) ⋅6 H O gives the diacetylene-based mixed-ligand coordination polymer {[Zn(L1)(L2)](DMF) } (UMON-44) in 38 % yield. Combination of DSC with variable-temperature single-crystal X-ray diffraction revealed the occurrence of two phase transitions spanning the ranges 129-144 K and 158-188 K. Furthermore, the three structurally similar phases of UMON-44 show giant negative and/or colossal positive thermal expansions. These unusual phenomena exist without any change in the contents of the unit cell. DFT calculations using the PBE+D3 dispersion scheme were able to distinguish between these polymorphs by accurately reproducing their salient structural features, although corrections in the size of the unit cell turned out to be necessary for the high-temperature phase to account for its large thermal expansion. In addition, the infrared spectra (vibration frequencies and peak intensities) of these theoretical models were calculated, allowing for univocal identification of the corresponding polymorphs. Last, the limits of our computational method were tested by calculating the phase transition temperatures and their associated enthalpies, and the derived figures compare favorably with the values determined experimentally.

Background. Surgical site infection is a major public health problem in the world. Nasal carriage is a major risk factor for the development of nosocomial Staphylococcus aureus infection, especially methicillin-resistant Staphylococcus aureus (MRSA). Our work aims to determine the prevalence of Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, and the associated risk factors and to evaluate their sensitivity to 27 antibiotics. Methods. A cross-sectional study was carried out on 100 patients, hospitalized in preoperative care of surgery units at the Taza Provincial Hospital Center in the Fez-Meknes region, from January to June 2019. Samples were taken from the patient’s anterior nostril using single-use sterile dry or wet cotton swabs and then analyzed in the Provincial Public Health Laboratory in Taza. The carriage of Staphylococcus aureus was studied by conventional bacteriological methods by spreading nasal swabs on Chapman culture medium, while antibiotic resistance was determined by the Mueller–Hinton agar disc diffusion method according to the recommendations described by the Antibiogram Committee of the French Society of Microbiology 2019 (CA SFM 2019). Results. Of the 84 patients found to be positive, 45.24% had coagulase-positive Staphylococcus aureus and 54.76% had coagulase-negative Staphylococcus. After surgery in the postoperative phase, 16 patients developed surgical site infections, of which two had a negative nasal culture and 14 had positive nasal culture. Among the Staphylococcus aureus-positive patients, 36.84% were colonized by a methicillin-resistant Staphylococcus aureus (MRSA) and 63.16% by a methicillin-sensitive Staphylococcus aureus (MSSA). Of these, 57.14% of MRSA colonized patients developed an infection of the surgical site and 42.85% showed no sign of SSI, while for patients colonized by MSSA, 16.67% developed SSI and 83.33% showed no sign of SSI. Moreover, children were the most affected by MRSA. Concerning antibiotic sensitivity, multiresistance of MRSA to more than 3 antibiotics has been found. Conclusion. To the best of our knowledge, this is the first study carried out in this hospital center with the aim of knowing the prevalence of nasal carriage of Staphylococcus aureus and MRSA and to identify the risk factors in order to prevent infections related to nasal carriage of Staphylococcus aureus and MRSA.

Three symmetrical diacetylenes (DAs) bearing tetraalkylammonium substituents have been prepared, namely, 1,6-bis(triethylammonium)hexa-2,4-diyne diiodide (2), dinitrate (3), and bis[bis(trifluoromethylsulfonyl)imide] (4). For these three salts, the duality between polymerization and carbonization has been investigated, and the results have been rationalized in terms of solid-state organization and molecular structure. These DAs have been irradiated at 254 nm with concomitant annealing at 80 °C (4) or 110 °C (2 and 3), and the lack of polydiacetylene (PDA) formation is in agreement with the fact that the CC–CC rods do not have a suitable orientation for 1,4-addition. Compound 4 is an ionic liquid. This DA starts melting at 88 °C with a maximum peak value of 104 °C, as ascertained by differential scanning calorimetry and thermogravimetric analyses. It is stable in the liquid state at 120 °C for several hours and remains unchanged at 170 °C for a few minutes without any sign of PDA formation, which means that if some kind of organization exists in the liquid phase, it is not helpful for 1,4-polymerization. Thermolyses of 2–4 have been conducted under a nitrogen flow up to 220 °C (3) and 1200 °C (2 and 4). In all three cases, graphite-like carbon materials were obtained. The graphite-like structures start to form around 200 °C, which is the temperature at which cycloaromatization of the triple bonds takes place. The residues from the pyrolyses of 2 and 4 exhibit nitrogen contents of 1.75 and 1.40 wt %, respectively, and powder X-ray diffraction and Raman analyses indicate that these materials have coherently scattering domain sizes in the range of 1–3 nm depending on the crystallographic direction. The Brunauer, Emmett, and Teller specific surface area of 2@1200 derived from dinitrogen sorption experiments is 88 m2 g–1 and that of 4@1200 is 33 m2 g–1. These values are much higher than those measured in previous works for carbon residues prepared at 1100 °C from imidazolium- and benzimidazolium-appended diacetylenes, thereby highlighting the pivotal influence of the size of the cation on the microstructure of the resulting carbon material. In addition, 2@1200 appears to be mostly microporous and 4@1200 mesoporous, which suggests that the anion also plays a central part in the structuring of the final solid. Last, X-ray photoelectron spectroscopy analysis of 4@1200 indicates that, besides nitrogen, this residue also contains small amounts of fluorine and sulfur, thus making carbonization of ionic diacetylenes an alternative method to introduce doping elements in a graphite structure.