The aim of this report is to present the electrospray ionization mass spectrometry results of the non-covalent interaction of two biologically active ligands, N-1-(p-toluenesulfonyl)cytosine, 1-TsC, 1 and N-1-methanesulfonylcytosine, 1-MsC, 2 and their Cu(II) complexes Cu(1-TsC-N3) Cl , 3 and Cu(1-MsC-N3) Cl and 4 with biologically important cations: Na , K , Ca , Mg and Zn . The formation of various complex metal ions was observed. The alkali metals Na and K formed clusters because of electrostatic interactions. Ca and Mg salts produced the tris ligand and mixed ligand complexes. The interaction of Zn with 1-4 produced monometal and dimetal Zn complexes as a result of the affinity of Zn ions toward both O and N atoms. Copyright © 2016 John Wiley & Sons, Ltd.
Shortly after introduction of commercial automatic chemical detectors, mostly based on ion mobility spectrometry technology, at the end of 20 th century field devices using other chemical detection techniques (FTIR, Raman, GC-MS, surface acoustic wave, photoacoustic, electrochemical, biosensor and others) were developed. Among these techniques, portable GC-MS detectors provide very reliable qualitative and quantitative chemical analysis, but high cost of these devices, the complexity of operating with them and the complexity of sample preparation for analysis present a problem. Some chemical detection technologies cannot be used for the development of a reliable hand-held chemical detector, and not a single technique, for the time being, allows the development of a universal chemical detector. A potential solution is the development of a multi-sensor device that compensates negative sides of each of the sensors. This paper provides an overview of commercially available chemical detectors based on new generation detection technologies and an overview of scientific research focused on further development of detection with simpler, more reliable and preferably cheaper solutions is given.
Detection of chemical warfare agents and toxic industrial chemicals is very important for security forces. For a long time it has been based on colorimetric chemistry, and only the development of electronics has made the automation and miniaturisation of chemical detection possible. At the end of the 20 th century, automatic chemical detectors, mostly based on ion mobility spectrometry technology (IMS), began to appear on the market. Nowadays, colorimetric detectors are increasingly being used again due to their excellent selectivity and low cost, and new chromogenic reagents are being developed. On the other hand, the development of IMS detectors is focused on the use of an asymmetric field since it allows smaller dimensions and greater sensitivity of the detector. In this paper, besides commercially available chemical detectors based on colorimetry and ion mobility spectroscopy techniques, an overview of scientific research focused on further development of these technologies with the goal of increasing selectivity and sensitivity is given.
The novel N-1-sulfonylcytosine-cyclam conjugates 1 and 2 conjugates are ionized by electrospray ionization mass spectrometry (ESI MS) in positive and negative modes (ES and ES ) as singly protonated/deprotonated species or as singly or doubly charged metal complexes. Their structure and fragmentation behavior is examined by collision induced experiments. It was observed that the structure of the conjugate dictated the mode of the ionization: 1 was analyzed in ES mode while 2 in positive mode. Complexation with metal ions did not have the influence on the ionization mode. Zn and Cu complexes with ligand 1 followed the similar fragmentation pattern in negative ionization mode. The transformation from 2°-amine in 1 to 3°-amine of cyclam ring in 2 leads to the different fragmentation patterns due to the modification of the protonation priority which changed the fragmentation channels within the conjugate itself. Cu ions formed complexes practically immediately, and the priority had the cyclam portion of the ligand 2. The structure of the formed Zn complexes with ligand 2 depended on the number of 3° amines within the cyclam portion of the conjugate and the ratio of the metal:ligand used. The cleavage of the cyclam ring of metal complexes is driven by the formation of the fragment that suited the coordinating demand of the metal ions and the collision energy applied. Finally, it was shown that the structure of the cyclam conjugate dictates the fragmentation reactions and not the metal ions.
We report about the selective reduction of eight cyclohexanones with NaBH 4 in aqueous solutions of bcyclodextrin, PEG-400, cationic micelles of CTAB and CPC, anionic micelles of SDS and SS at room temperature and at 808C. All results were compared with NMR, GC-MS as well as with IR. The charge of the micellar head group influences the preferential direction of hydride attack by favoring one reactant conformation over the other and the outcome is more products with the H 2 in the axial position. One example is the reduction of ketone 4. It was obtained 73% of trans 4-tert-butylcyclohexanol in CTAB, 90% in SDS and 94% in SS micelles. The importance of this work is in the obtained selectivity, the high yields, and the simplicity.
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