scholarly journals Syntheses and Reactivity of New Zwitterionic Imidazolium Trihydridoborate and Triphenylborate Species

Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3184
Author(s):  
Maura Pellei ◽  
Riccardo Vallesi ◽  
Luca Bagnarelli ◽  
H. V. Rasika Dias ◽  
Carlo Santini

In this study, four new N-(alkyl/aryl)imidazolium-borates were prepared, and their deprotonation reactions were investigated. Addition of BH3•THF to N-benzylimidazoles and N-mesitylimidazoles leads to imidazolium-trihydridoborate adducts. Ammonium tetraphenylborate reacts with benzyl- or mesityl-imidazoles with the loss of one of the phenyl groups yielding the corresponding imidazolium-triphenylborates. Their authenticity was confirmed by CHN analysis, 1H-NMR, 13C-NMR, 11B-NMR, FT-IR spectroscopy, and electrospray ionization mass spectrometry (ESI-MS). 3-Benzyl-imidazolium-1-yl)trihydridoborate, (HImBn)BH3, and (3-mesityl-imidazolium-1-yl)trihydridoborate, (HImMes)BH3, were also characterized by X-ray crystallography. The reactivity of these new compounds as carbene precursors in an effort to obtain borate-NHC complexes was investigated and a new carbene-borate adduct (which dimerizes) was obtained via a microwave-assisted procedure.

Author(s):  
Wei Huang ◽  
Wen-Ling Wang

Two α-amino-phosphonate derivatives (1 & 2) were synthesized and their compositions and structures were characterized by Elemental Analysis (EA), FT-IR Spectrascopy (FT-IR), Electrospray Ionization Mass Spectrometry (ESI-MS), Nuclear Magnetic Resonance (NMR, 1H, 13C and 31P) and X-ray crystallography. Compound 1 & 2 were crystallized in monoclinic system with the space group P2(1)/n and P2(1)/c, respectively. The interaction effects of two α-aminophosphonate derivatives (1 & 2) with BSA were investigated and the binding constants were 1.07 × 104 M-1, 1.68 × 104 M-1, respectively. Besides, the values of n were indicated that 1:1 complex was formed between BSA and 1&2.


2021 ◽  
pp. 174751982198965
Author(s):  
Guoqi Zhang

( E)-4-[2-(Pyridin-4-yl)vinyl]benzaldehyde, containing both a 4-vinylpyridine and an aldehyde functionality, is utilized to develop new, highly conjugated chalcone compounds and a bis-Schiff base azine compound. The chalcone-containing compounds are further explored for their protonation, methylation and silver(I) coordination chemistry using the pyridine moiety. In parallel, a cyano-containing analogue, ( E)-4-[2-(pyridin-4-yl)vinyl]benzonitrile is also synthesized and studied for its silver(I) coordination chemistry. These new compounds are fully characterized by mass spectrometry, elemental analysis and spectroscopic techniques. The methylated product of ( E)-1-(9-anthryl)-3-{4-[2-(pyridin-4-yl)vinyl]phenyl}prop-2-en-1-one and a silver complex of ( E)-4-[2-(pyridin-4-yl)vinyl]benzonitrile are structurally determined by X-ray crystallography.


2019 ◽  
Vol 20 (3) ◽  
pp. 520 ◽  
Author(s):  
Giarita Ferraro ◽  
Tiziano Marzo ◽  
Maria Cucciolito ◽  
Francesco Ruffo ◽  
Luigi Messori ◽  
...  

Stable five-coordinate Pt(II) complexes have been highlighted as a promising and original platform for the development of new cytotoxic drugs. Their interaction with proteins has been scarcely studied. Here, the reactivity of the five-coordinate Pt(II) compound [Pt(I)(Me) (dmphen)(olefin)] (Me = methyl, dmphen = 2,9-dimethyl-1,10-phenanthroline, olefin = dimethylfumarate) with the model proteins hen egg white lysozyme (HEWL) and bovine pancreatic ribonuclease (RNase A) has been investigated by X-ray crystallography and electrospray ionization mass spectrometry. The X-ray structures of the adducts of RNase A and HEWL with [Pt(I)(Me)(dmphen)(olefin)] are not of very high quality, but overall data indicate that, upon reaction with RNase A, the compound coordinates the side chain of His105 upon releasing the iodide ligand, but retains the pentacoordination. On the contrary, upon reaction with HEWL, the trigonal bi-pyramidal Pt geometry is lost, the iodide and the olefin ligands are released, and the metal center coordinates the side chain of His15 probably adopting a nearly square-planar geometry. This work underlines the importance of the combined use of crystallographic and mass spectrometry techniques to characterize, in detail, the protein–metallodrug recognition process. Our findings also suggest that five-coordinate Pt(II) complexes can act either retaining their uncommon structure or functioning as prodrugs, i.e., releasing square-planar platinum complexes as bioactive species.


2016 ◽  
Vol 71 (1) ◽  
pp. 81-84 ◽  
Author(s):  
Eugen Weisheim ◽  
Hans-Georg Stammler ◽  
Norbert W. Mitzel

AbstractThe reaction of 1,3,5-triethynyl-1,3,5-trimethyl- 1,3,5-trisilacyclohexane with (dimethylamino)trimethylstannane afforded 1,3,5-tris[(trimethylstannyl)ethynyl]- 1,3,5-trimethyl-1,3,5-trisilacyclohexane with tin-functionalised ethynyl groups. The compound was characterized by single-crystal X-ray diffraction, elemental analysis, mass spectrometry, NMR and FT-IR spectroscopy.


The Analyst ◽  
2018 ◽  
Vol 143 (6) ◽  
pp. 1475-1481 ◽  
Author(s):  
Yukako Hayashi ◽  
Kazuaki Ohara ◽  
Rika Taki ◽  
Tomomi Saeki ◽  
Kentaro Yamaguchi

The combination of X-ray analysis and laser desorption ionization by using crystalline sponge will be a promising method to determine guest structures.


2014 ◽  
Vol 70 (8) ◽  
pp. 2217-2231 ◽  
Author(s):  
Philippe Bénas ◽  
Nicolas Auzeil ◽  
Laurent Legrand ◽  
Franck Brachet ◽  
Anne Regazzetti ◽  
...  

The adsorption of Rb+, Cs+, Mn2+, Co2+and Yb3+onto the positively charged hen egg-white lysozyme (HEWL) has been investigated by solving 13 X-ray structures of HEWL crystallized with their chlorides and by applying electrospray ionization mass spectrometry (ESI-MS) first to dissolved protein crystals and then to the protein in buffered salt solutions. The number of bound cations follows the order Cs+< Mn2+≃ Co2+< Yb3+at 293 K. HEWL binds less Rb+(qtot= 0.7) than Cs+(qtot= 3.9) at 100 K. Crystal flash-cooling drastically increases the binding of Cs+, but poorly affects that of Yb3+, suggesting different interactions. The addition of glycerol increases the number of bound Yb3+cations, but only slightly increases that of Rb+. HEWL titrations with the same chlorides, followed by ESI-MS analysis, show that only about 10% of HEWL binds Cs+and about 40% binds 1–2 Yb3+cations, while the highest binding reaches 60–70% for protein binding 1–3 Mn2+or Co2+cations. The binding sites identified by X-ray crystallography show that the monovalent Rb+and Cs+preferentially bind to carbonyl groups, whereas the multivalent Mn2+, Co2+and Yb3+interact with carboxylic groups. This work elucidates the basis of the effect of the Hofmeister cation series on protein solubility.


Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1456
Author(s):  
Manas Sutradhar ◽  
Marta A. Andrade ◽  
Sónia A. C. Carabineiro ◽  
Luísa M. D. R. S. Martins ◽  
Maria de Fátima C. Guedes da Silva ◽  
...  

Oxidovanadium(V) and dioxidovanadium(V) compounds, [VO(OEt)L] (1) and [Et3NH][VO2L] (2), were synthesized using an aroylhydrazone Schiff base (5-bromo-2-hydroxybenzylidene)-2-hydroxybenzohydrazide (H2L). They were characterized by elemental analysis, Fourier-transform infrared spectroscopy (FT-IR), (1H and 51V) nuclear magnetic resonance (NMR), electrospray ionization mass spectrometry (ESI-MS) and single crystal X-ray diffraction analyses. Both complexes were immobilized on functionalized carbon nanotubes and activated carbon. The catalytic performances of 1 and 2, homogenous and anchored on the supports, were evaluated for the first time towards the MW-assisted peroxidative oxidation (with tert-butylhydroperoxide, TBHP) of cyclohexane under heterogeneous conditions. The immobilization of 1 and 2 on functionalized carbon materials improved the efficiency of catalytic oxidation and allowed the catalyst recyclability with a well-preserved catalytic activity.


2021 ◽  
Vol 12 ◽  
Author(s):  
Hayden E. Hodges ◽  
Heather J. Walker ◽  
Aaron J. Cowieson ◽  
Robert J. Falconer ◽  
Duncan D. Cameron

Modern feed quality sorghum grain has been bred to reduce anti-nutrients, most conspicuously condensed tannins, but its inclusion in the diets of monogastric animals can still result in variable performance that is only partially understood. Sorghum grain contains several negative intrinsic factors, including non-tannin phenolics and polyphenols, phytate, and kafirin protein, which may be responsible for these muted feed performances. To better understand the non-tannin phenolic and polyphenolic metabolites that may have negative effects on nutritional parameters, the chemical composition of sorghum grain polyphenol extracts from three commercial varieties (MR-Buster, Cracka, and Liberty) was determined through the use of an under-studied, alternative analytical approach involving Fourier-transform infrared (FT-IR) spectroscopy and direct ionization mass spectrometry. Supervised analyses and interrogation of the data contributing to variation resulted in the identification of a variety of metabolites, including established polyphenols, lignin-like anti-nutrients, and complex sugars, as well as high levels of fatty acids which could contribute to nutritional variation and underperformance in monogastrics. FT-IR and mass spectrometry could both discriminate among the different sorghum varieties indicating that FT-IR, rather than more sophisticated chromatographic and mass spectrometric methods, could be incorporated into quality control applications.


2010 ◽  
Vol 63 (2) ◽  
pp. 252 ◽  
Author(s):  
Jingli Xie ◽  
Ryan Gilbert-Wilson ◽  
Boujemaa Moubaraki ◽  
Keith S. Murray ◽  
Anthony G. Wedd

Two new hybrid materials [Fe(bipy)3]3[ZnW12O39(OH)Fe(bipy)2(H2O)]2 and [Fe(bipy)3]2[CoW12O40] were obtained by hydrothermal synthesis. They contain [Fe(bipy)3] n+ (bipy = 2,2′-bipyridyl; n = 2 or 3) cations and Keggin-type polyoxotungstate anions. Both have been characterized by elemental analysis, FT-IR spectroscopy, 1H-NMR spectrometry, and single crystal X-ray crystallography. The anion in the former salt features [FeII(bipy)2(OH2)]2+ units covalently bound via a W=O-Fe bridge to the protonated anion [ZnW12O39(OH)]5–. The latter salt contains discrete [CoW12O40]6– anions.


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