Ammonium hydrogen (RS)-[(5-methyl-2-oxo-1,3-oxazolidin-3-yl)meth­yl]phospho­nate

In the title compound, NH4 +·C5H9NO5P−, the five-membered methyl­oxazolidin-2-one unit is disordered over two positions, the major component having a site occupancy of 0.832 (9). A three-dimensional network of O—H⋯O and N—H⋯O hydrogen bonds stabilizes the crystal structure

A new monoclinic polymorph of dichlorido­tetra­kis(dimethyl sulfoxide)­ruthenium(II)

The title compound, cis,fac-dichloridotetra­kis(dimethyl sulfoxide)-κ3 S,κO-ruthenium(II), [RuCl2(C2H6OS)4], was obtained from newly synthesized ruthenium complexes of 3-amino-2-chloro­pyridine. The Ru atom has a distorted octa­hedral coordination with two cis-oriented chloride ligands and four dimethyl sulfoxide ligands. Three of the sulfoxide ligands are S-bonded in a fac configuration, while the fourth is O-bonded. The title compound represents a new, and fourth, polymorph of the complex. Two other monoclinic forms and an ortho­rhom­bic modification have been reported previously

Betti bases from 4-(3-pyridazo)-1-naphthol: synthesis, coordination behaviour and unusual substitution reactions

A series of Betti bases from 4‐(3‐pyridyl)azo‐1‐naphthol dye, possessing flexible methylene or more constrained aryl‐methyne spaced NH‐containing side‐chains, were obtained and characterized. It was shown by NMR spectroscopy that the ligands exist in keto form. The products’ structure was confirmed by single crystal XRD of a selected sample. A study on the coordination ability of the ligands with silver(I) was performed, leading to an unexpected substitution reaction

Controlled tautomeric switching in azonaphthols tuned by substituents on the phenyl ring

A series of new tautomeric azonaphthols are synthesized and the possibilities for molecular switching are investigated using molecular spectroscopy, X-ray analysis and density functional theory quantum chemical calculations. Two opposite effects that influence switching are studied: attaching a piperidine sidearm, and adding substituents to the phenyl ring. On the one hand, the attached piperidine moiety stabilizes the enol form leading to a controlled shift of the equilibrium upon protonation. On the other hand, the relative stability of the azonaphthol tautomers strongly depends on the effects of the substituents on the phenyl ring: electron donors tend to stabilize the enol tautomer, whereas electron acceptors lead to stabilization of the keto form. However, these effects do not shift fully the equilibrium towards either of the tautomers. Nevertheless, the effect of the substituents can be an additional tool to affect the switching between “on” and “off” states. Electron-withdrawing substituents stabilize the keto form and impede switching to the off state, whereas electron donors stabilize the enol form. The effect of the piperidine unit is dominant overall, and with strongly electron-withdrawing substituents at the phenyl ring, the enol form exists as a zwitterion

Synthesis, characterization and complex evaluation of antibacterial activity and cytotoxicity of new arylmethylidene ketones and pyrimidines with camphane skeletons

The synthesis of 20 arylidenecamphors and 15 pyrimidines with camphane skeleton is described in the current report. A modified method for preparation of sterically hindered 2- aminopyrimidines in two steps was demonstrated. The evaluation of their in vitro activity against Mycobacterium tuberculosis H37Rv showed different MIC values (up to 0.91 μM for ketone 39). Compound 35 demonstrated moderate (8.23 μM), but sustainable activity toward a collection of drug-resistant M. tuberculosis strains. Many of the compounds (especially among 2-aminopyridines 42–56) exhibited good to excellent activity against different strains of pathogenic bacteria and fungi (MIC up to 0.60 μM for compound 50), compared with reference antibiotics. Many of the newly designed compounds possess also in vitro cytotoxicity.This study was supported by: Bulgarian National Science Fund- project KP-06-H39/7 and Spanish Ministry of Science, Innovation and Universities- Grant RTI2018-094629-BI00. MEDINA’s authors disclosed the receipt of financial support from Fundación MEDINA, a public-private partnership of Merck Sharp and Dohme de EspañaS.A./Universidad de Granada/Junta de Andalucía

Synthetic Amorphous Silicon Dioxide (NM-200, NM-201, NM-202, NM-203, NM-204): Characterisation and Physico-Chemical Properties

The European Commission's Joint Research Centre (JRC) provides scientific support to European Union policy including nanotechnology. Within this context, the JRC launched, in February 2011, a repository for Representative Test Materials (RTMs), based on preparatory work started in 2008. It supports both EU and international research projects, and especially the OECD Working Party on Manufactured Nanomaterials (WPMN). The WPMN leads an exploratory testing programme "Testing a Representative set of Manufactured Nanomaterials" for the development and collection of data on characterisation, toxicological and ecotoxicological properties, as well as risk assessment and safety evaluation of nanomaterials. The purpose is to understand the applicability of the OECD Test Guidelines for the testing of nanomaterials as well as end-points relevant for such materials. The Repository responds to a need for nanosafety research purposes: availability of nanomaterial from a single production batch to enhance the comparability of results between different research laboratories and projects. The availability of representative nanomaterials to the international scientific community furthermore enhances and enables development of safe materials and products. The present report presents the physico-chemical characterisation of the synthetic amorphous silicon dioxide (SiO2, SAS) from the JRC repository: NM-200, NM-201, NM-202, NM-203 and NM-204. NM-200 was selected as principal material for the OECD test programme "Testing a representative set of manufactured nanomaterials". NM-200, NM-201 and NM-204 (precipitated SAS) are produced via the precipitation process, whereas NM-202 and NM-203 (fumed or pyrogenic SAS) are produced via a high temperature process. Each of these NMs originates from one respective batch of commercially manufactured SAS. They are nanostructured, i.e. they consist of aggregated primary particles. The SAS NMs may be used as a representative material in the measurement and testing with regard to hazard identification, risk and exposure assessment studies. The results for more than 15 endpoints are addressed in the present report, including physical-chemical properties, such as size and size distribution, crystallite size and electron microscopy images. Sample and test item preparation procedures are addressed. The results are based on studies by several European laboratories participating to the NANOGENOTOX Joint Action, as well as the JRC.JRC.I.4-Nanobioscience

Multi-walled Carbon Nanotubes, NM-400, NM-401, NM-402, NM-403: Characterisation and Physico-Chemical Properties

In 2011 the JRC launched a Repository for Representative Test Materials that supports both EU and international research projects, and especially the OECD Working Party on Manufactured Nanomaterials' (WPMN) exploratory testing programme "Testing a Representative set of Manufactured Nanomaterials" for the development and collection of data on characterisation, toxicological and ecotoxicological properties, as well as risk assessment and safety evaluation of nanomaterials. The JRC Repository responds to a need for availability of nanomaterial from a single production batch to enhance the comparability of results between different research laboratories and projects. The present report presents the physico-chemical characterisation of the multi-walled carbon nanotubes (MWCNT) from the JRC Repository: NM-400, NM-401, NM-402 and NM-403. NM-400 was selected as principal material for the OECD WPMN testing programme. They are produced by catalytic chemical vapour deposition. Each of these NMs originates from one respective batch of commercially manufactured MWCNT. They are nanostructured, i.e. they consist of more than one graphene layer stacked on each other and rolled together as concentric tubes. The MWCNT NMs may be used as a representative material in the measurement and testing with regard to hazard identification, risk and exposure assessment studies. The results are based on studies by several European laboratories participating to the NANOGENOTOX Joint Action.JRC.I.4-Nanobioscience

Titanium Dioxide, NM-100, NM-101, NM-102, NM-103, NM-104, NM-105: Characterisation and Physico-Chemical Properties

The European Commission's Joint Research Centre (JRC) provides scientific support to European Union policy including nanotechnology. Within this context, the JRC launched, in February 2011, a repository for Representative Test Materials (RTMs), based on preparatory work started in 2008. It supports both EU and international research projects, and especially the OECD Working Party on Manufactured Nanomaterials (WPMN). The WPMN leads an exploratory testing programme "Testing a Representative set of Manufactured Nanomaterials" for the development and collection of data on characterisation, toxicological and ecotoxicological properties, as well as risk assessment and safety evaluation of nanomaterials. The purpose is to understand the applicability of the OECD Test Guidelines for the testing of nanomaterials as well as end-points relevant for such materials. The Repository responds to a need for nanosafety research purposes: availability of nanomaterial from a single production batch to enhance the comparability of results between different research laboratories and projects. The availability of representative nanomaterials to the international scientific community furthermore enhances and enables development of safe materials and products. The present report presents the physico-chemical characterisation of the Titanium dioxide series from the JRC repository: NM-100, NM-101, NM-102, NM-103, NM-104 and NM-105. NM-105 was selected as principal material for the OECD test programme "Testing a representative set of manufactured nanomaterials". NM-100 is included in the series as a bulk comparator. Each of these NMs originates from one batch of commercially manufactured TiO2. The TiO2 NMs may be used as representative material in the measurement and testing with regard to hazard identification, risk and exposure assessment studies. The results for more than 15 endpoints are addressed in the present report, including physico-chemical properties, such as size and size distribution, crystallite size and electron microscopy images. Sample and test item preparation procedures are addressed. The results are based on studies by several European laboratories participating to the NANOGENOTOX Joint Action, as well as by the JRC.JRC.I.4-Nanobioscience