The applicability of ionic liquids (ILs) has been increased during the last years and even new opportunities are becoming a reality, for example mixtures of pure IL and inorganic salt as electrolytes for smart electrochemical devices. Some authors have stated the improvements of the properties of ILs after doping with a common anion inorganic salt (specially lithium salt). One of the most distinctive property of ILs is their negligible vapour pressure, since ILs are usually treated as “green solvents, although the high probability of a spill and filtration into aquatic environment lead us to perform deeper studies on ecotoxicity of these compounds.

In this work, the ecotoxicity of two protic ILs (Ethylammonium nitrate (EAN) and Ethylimidazolium nitrate (EIm NO₃)) and one aprotic IL (butylmethylpyrrolidinium bis(trifluoromethylsulfonyl)imide (C₄C₁pyrr TFSI)) doped with the corresponding Lithium salt (LiNO3_,, for the protic ILs and LiTFSI for the aprotic IL) was tested towards changes on the bioluminescence of the bacteria Aliivibrio fischeri, using the Microtox® standard toxicity test. The effective concentration (EC50) of these mixtures was determined over three standard periods of time, namely 5, 15 and 30 min and compared with the corresponding values to pure ILs.

Results of EC₅₀ at 15 minutes for these compounds, show pure EAN as the less toxic, meanwhile C₄C₁pyrr TFSI and EIm NO₃ present slight toxicity. Addition of salt leads to interesting results, LiNO₃ seems to induce to less toxic mixtures and LiTFSI provokes an increase on toxicity of the final compound.

In recent years, some controversy has been running related to the origin of the substituent effect in π-π interactions. The earlier model based on ring polarisation and electrostatic interactions does not seem to be able to describe the observed effects, so a new model considering that substituent effect comes from the direct interaction between the substituent and the other ring has been proposed. In any case, the net effect of the substituent is largely dependent on other variables, and attention has been recently called upon the fact that the distance between rings can alter the observed behaviour. In a recent work (PCCP 2020, 22, 12068) we have shown that the origin of the substituent effect can change depending on the relative position of the substituent and the interacting rings. In the present study, an extension of the previous work is performed by using similar systems but changing the substituent , now located in a pyridine ring, and thus changing the relative positions of the substituent and the interacting rings.

One-step synthesis of cyclopentadienylzirconacyclopentadienes via the reaction of alkynes with Cp₂ZrCl₂ - Mg system is well established reaction. However, this procedure has not received wide synthetic application and is currently superseded by Negishi and Takahashi reagents. According to the literature the preparation of zirconacyclopentadienes from 3-hexyne needs the use of stoichiometric amounts of HgCl₂ that makes this methodology unattractive for widespread use. Thus the development of a new effective method for the homo-coupling of alkynes which excludes the use of both pyrophoric organometallic compounds and salts of toxic heavy metals could contribute to a wider use of the Cp₂ZrCl₂ - Mg system for the preparation of diene derivatives and cyclization of enynes. We found that 10 mol % of AlCl₃ significantly accelerates the cyclozirconation of alkyl-substituted alkynes giving after iodinolysis the corresponding iodine-containing homo-coupling products in a quantitative yield. Thus, the reaction of 5-decyne with one equivalent each of Cp₂ZrCl₂ and Mg in THF in the presence of 10 mol % of AlCl₃ proceeds with complete conversion of alkyne into zirconacyclopentadiene at room temperature in less than 10 minutes. Similarly, catalytic amounts of AlCl₃ accelerate the reaction with aryl- and silyl-substituted alkynes. At the same time, the reaction of 5-decyne with Cp₂ZrCl₂ and Mg in THF at room temperature without AlCl₃ does not proceed even overnight. The use of catalytic amounts of Me₃SiCl or InCl₃ instead of AlCl₃ also did not lead to the formation of the dimerization product after 5 hours at room temperature.

The current interest on Ionic liquids (ILs) is motivated by their exceptional properties, such as negligible vapour pressure, high thermal stability high ionic conductivity and wide electrochemical window, being especially interesting as advanced materials for smart electrochemical devices as supercapacitors, dye-sensitized solar cells or lithium and aluminium batteries.

In spite of their applicability and the high probably of a spill and filtration into terrestrial and aquatic environment, studies about their toxicity on these environments are very unusual.

In this work, the ecotoxicity of a mixture of an ionic liquid, ethylammonium nitrate (EAN), and aluminium nitrate salt (Al(NO₃)₃) was studied. This mixture has singular interest as electrolyte in electrochemical applications. The ecotoxicity of pure EAN and aluminium nitrate were also investigated. Changes on microbial activity of two soils with different organic matter content (measured by microcalorimetry) and on the bioluminescence generated by the bacteria Aliivibrio fischeri (Beijerinck) Urbanczyk through Microtox® test, when exposed to solutions of different concentrations of these compounds, were analysed.

Heat released by soil microorganisms decreases with the dose for both soils and the three compounds, except for the lowest concentrations which present similar power-time curves than the corresponding control. There is a lag period in heat release, longer as the dose increases and when Al is present. Pure IL seems to be less toxic than mixtures and pure salt on both soils. Opposite response was observed for A. fischeri, for which the highest EC₅₀ values were obtained for pure salt and the lowest for pure EAN.

2,2-Dimethyl-5-((phenylamino)methylene)-1,3-dioxane-4,6-dione, prepared by ternary condensation of Meldrum’s acid with triethyl orthoformate and aniline, reacts with N-aryl cyanoacetamides in the presence of KOH to give 2-oxo-1,2-dihydropyridine-3-carboxylic acids, which are useful as drug precursors or perspective ligands.

Aphis craccivora is an aphid which damages many species of plants, but with a higher predilection for beans, and is also a vector for numerous plant viruses. Therefore, to find potent and relatively safe insecticides against it may be a justified desideratum. Since neonicotinoids are a well-known class of effective insecticides with less toxicity against mammals and other vertebrates, a small dataset of compounds retrieved from literature based on similarity with highly active neoticotinoids was used. The dataset was preliminary investigated using the BeeTox tool to predict the bee toxicity of these compounds. They were found to be safe. In the absence of experimental data in silico approaches, such as molecular modelling methods, are considered to be reliable alternatives. Thus, homology modelling was involved for the building of the 3D structure of the acetylcholine receptor subunit alpha-L1 of Aphis craccivora based on the X-ray structure of human nicotinic acetylcholine receptor (PDB ID: 6PV7). The 3D structure of the obtained homology model is a dimer and the identified binding site is located between its two repeated units. After the refinement and evaluating steps, the homology model was involved in virtual screening experiments using the Fred docking tool of the OpenEye software. The aforementioned dataset was used to explore the intermolecular ligand-target interaction patterns for a rational design of desired insecticides. The hydrophobic interactions with the following amino acids of the binding site: Trp149, Trp59, Tyr190, Tyr197, Leu123, Ile113 were found to be the main ligand-protein binding mechanism.

An optically active bicyclo[2.2.0]heptane fragment was introduced in the molecule of new 1’-homonucleosides on a 2- 6-chloro-amino-purine scaffold to obtain 6-substituted carbocicloc nucleozide analogues as antiviral compounds. The synthesis was realized by a Mitsunobu reaction of the base with the corresponding bicyclo[2.2.0]heptane intermediate ant then the nucleoside analogues were obtained by substitution of the 6-chlorime with selected pharmaceutically accepted amines. A molecular docking study of the compounds on influenza, HSV and low active Coronavirus was realized. Experimental screening of the compounds on the same viruses are developing and soon will be finished.

Drug repositioning involves the investigation of existing drugs for new therapeutic purposes such as type 2 diabetes. This disease affects the health and quality of life for individuals around the world. Sitagliptin, a highly selective dipeptidyl peptidase-4 (DPP-4) inhibitor, is used to treat type 2 diabetes mellitus by effective fasting and improved glycemic control. Despite this advantage, serious hypersensitivity reactions have been acknowledged for patients receiving sitagliptin. In this context, new drugs with enhanced profile and targeting DPP-4 are necessary to be developed. Sitagliptin, ((2R)-4-oxo-4-[3-(trifluoromethyl)-5,6-dihidro[1,2,4]triazolo[4,3-A] pirazin-7(8H)-yl]-1-(2,4,5-trifluorophenyl)butan-2-amine), was used as a query in a 3D similarity search (ROCS, OpenEye) on the approved DrugBank. Based on the TanimotoCombo parameter, the first 10 approved DrugBank drugs were docked using FRED from OpenEye package in the 4FFW active site to identify effective anti-diabetic effects for possible repurposable drugs marketed with other indications.

Ionic liquids (ILs) represents, nowadays, a real alternative for electrochemical applications such as organic solvents, electrolytes, dye-sensitized solar cells, lubricants and sensors among others, due to their amazing characteristics, namely a very low vapour pressure, low flammability, high thermal stability, wide potential window and high ionic conductivity. In this work, Nyquist plot and impedance spectroscopy at room temperature is proposed as an alternative method, using a RLC precision meter Agilent HP 4284 A, to obtain the ionic conductivity for ionic liquids in the frame of dielectric constant in the frequency range of 1 Hz to 1 MHz, by determination of the conductive regime through frequency dependence. For this propose, the IL 1-butyl-3-methylimidazolium tetrafluoroborate (C₄C₁Im BF₄) was selected and results were compared with the previously obtained from the conductimeter CRISON GLP31 at a constant frequency of 500 Hz.

Ionic Liquids (ILs) represent a viable option as electrolytes as many electrochemical applications such as energy storage devices due to their competitive features in contrast to the options used today due, mainly, their high ionic conductivity and wide electrochemical window. However, liquid electrolytes present important problems of safety and performance, and encapsulation in solid matrix can be a good solution to improve it. In this work, changes on the structure of the mixtures of ionic liquid 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (C₄C₁Pyrr TFSI) and Lithium bis(trifluoromethylsulfonyl)imide (Li TFSI) against the concentration of the salt (pure IL, 0.1 and 1.5 molal of salt addition) were studied using NMR technique. Moreover, the effect of nanoconfinement of these mixtures through gelation process was also analysed.

The salt addition does not have a significant influence in the structural arrange of the cation of the IL in both liquid and gel states, while over the gelation of the liquid sample has a result a slight slowdown of the molecular dynamics, although a liquid behaviour was observed inside the organic matrix.