5422-44-6Relevant academic research and scientific papers
Molecular structure of nitrogen-linked methyltetrazole-saccharinates
Ismael, Amin,Paix?o, José António,Fausto, Rui,Cristiano, Maria Lurdes S.
, p. 128 - 142 (2012)
The molecular structures of nitrogen-linked 1- and 2-methyltetrazole- saccharinates, were investigated in the crystalline phase using X-ray crystallography and infrared and Raman spectroscopies, complemented by quantum chemical calculations performed at the DFT(B3LYP)/6-31++G(d,p) level of theory for the isolated molecules. In the neat crystalline solid (space group P1?, a = 6.9763 ?, b = 8.3097 ?, c = 10.0737 ?, α = 96.517°, β = 107.543°, γ = 99.989°; Z = 2), 1-methyltetrazole-saccharinate units assume the most stable configuration for the isolated molecule, (1H)-1-methytetrazole iminosaccharin tautomeric form (1MTIS), with the NC spacer linking the two heterocycles. On the other hand, neat crystalline 2-methyl derivative units (space group P1?, a = 7.8010 ?, b = 8.6724 ?, c = 9.4984 ?, α = 114.083°, β = 107.823°, γ = 93.080°; Z = 2) exist in the (2H)-2-methytetrazole aminosaccharin tautomeric form (2MTAS), with the two heterocycles connected by an NH spacer. In both crystals, the structure consists of a packing of dimeric units, the dimers formed via hydrogen bonding involving either the NH group of the saccharyl system (1MTIS) or the spacer amine group (2MTAS). In the former, the hydrogen bond is bifurcated and the NH group acts as a donor both towards a neighbor molecule and an N atom of the tetrazole ring, forming an intramolecular hydrogen bond. The observed difference in the crystallographic basic units of the two compounds reveals the prevalence of the H-bond networks in determining the structural preferences of the tetrazole-saccharinates in the solid state. Such structural flexibility appears also to be of potential interest in the design of new ligands based on the tetrazole-saccharinate framework. The relative strengths of the H-bonds in the crystals of the two compounds were evaluated through inspection of their vibrational spectra and empirical correlations between spectroscopic data and the H-bond enthalpies and distances.
Energetic silver salts with 5-aminotetrazole ligands
Karaghiosoff, Konstantin,Klapoetke, Thomas M.,Sabate, Caries Miro
, p. 1164 - 1176 (2009)
Methylation of 5-amino-1H-tetrazole (1) gives 1-methyl-5-amino-1H-tetrazole (2) and 2-methyl-5-amino-1H-tetrazole (3). A new family of energetic silver complexes based on ligands 1, 2 and 3 with Perchlorate and nitrate anions (10-15) were synthesized and characterized by using IR, Raman, and NMR ( 1H, 13C, 14N, and 35Cl NMR) spectroscopy, elemental analysis, and mass spectrometry. The crystal structures of the compounds were determined where possible and reveal interesting structural details that are discussed herein. Additionally, differential scanning calorimetry was used to assess the thermal stability of the new salts, which showed excellent thermal stabilities at temperatures up to and above 225 °C. Standard tests were also used to assess the sensitivity of the materials towards impact and friction. All the silver complexes showed increased sensitivity values in comparison with analogous protonated 5-amino-1H- tetrazolium Perchlorate and nitrate salts. Some of these materials have sensitivity values that are comparable to commonly used primary explosives and allof them either deflagrate (12-14) or detonate loudly (10 and 11) on contact with an open flame. Lastly, nitrate salt 11 is easily initiated by thermal shock. It shows reasonably low sensitivity in comparison with other silver salts (e.g., silver azide or silver fulminate), which makes handling it much less hazardous. Compound 11 also has good thermal stability, decomposing at ≈300 °C, and shows interesting properties as a more environmentally benign alternative to lead(II) diazide in initiation devices for civil and military applications.
Electron transfer in a trinuclear oxo-centred mixed-valence iron complex, in solid and solution states
Stadler,Daub,Koehler,Saalfrank,Coropceanu,Schuenemann,Ober,Trautwein,Parker,Poyraz,Inomata,Cannon
, p. 3373 - 3383 (2001)
Complexes [FeIII2MIIOL3] (M = Fe, Co, Ni, Cu; 2, 3, 4, 5) have been synthesised in which L2- is a pentadentate ligand designed to coordinate all three metal atoms in the central cluster and to inhibit dissociation and solvent exchange processes. Crystal structures for 2, 4 and 5 show threefold symmetry, attributed to rotational disorder. Magnetisation data for 2 indicate strong superexchange between basis oxidation states Fe(3+, 3+, 2+). Comparisons of IR spectra across the series of complexes confirm the non-threefold symmetry of the mixed-valence cluster on the vibrational time scale, both in the solid state and in solution. Proton NMR spectra in solution at room temperature do not distinguish the three iron sites, suggesting that pseudo-rotation by thermal electron transfer also operates. Cyclic voltammetry and spectroelectrochemical measurements show that the mixed-valence iron complex 2 can be oxidised reversibly to give the tri-iron(III) complex [Fe3OL3]+ and reduced reversibly and quasireversibly to give respectively [Fe3OL3]- and tri-iron(II) [Fe3OL3]2-, E0 = 85,-635, -1230 mV (versus Fc+/0) in dichloromethane (T = 298 K, 0.1 M [n-Bu4N][PF6]). Moessbauer spectra of 2 indicate significant valence delocalisation even at low temperature (4.2 K) with estimated valences Fe(2.9+, 2.9+, 2.2+) in the solid state. At higher temperatures no lifetime broadening is observed but additional Moessbauer absorptions are consistent with increasing proportions of trimer molecules with greater delocalisation, i.e. Fe(2.75+, 2.75+, 2.5+). In frozen solution (THF) the spectra indicate increasing proportions of molecules fully valence-delocalised on the Moessbauer time scale. The data are accounted for with a model which places the complex at the Robin-Day class III/II borderline. It combines strong superexchange with significant double exchange even at the lowest temperatures, while at higher temperatures in solution complete valence delocalisation occurs through intramolecular electron transfer at rates intermediate between the IR and NMR time scales.
In vitro assessment of antimicrobial, antioxidant, and cytotoxic properties of saccharin–tetrazolyl and –thiadiazolyl derivatives: The simple dependence of the ph value on antimicrobial activity
Frija, Luís M. T.,Ntungwe, Epole,Sitarek, Przemys?aw,Andrade, Joana M.,Toma, Monika,?liwiński, Tomasz,Cabral, Lília,Cristiano, M. Lurdes S.,Rijo, Patrícia,Pombeiro, Armando J. L.
, (2019)
The antimicrobial, antioxidant, and cytotoxic activities of a series of saccharin–tetrazolyl and –thiadiazolyl analogs were examined. The assessment of the antimicrobial properties of the referred-to molecules was completed through an evaluation of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values against Gram-positive and Gram-negative bacteria and yeasts. Scrutiny of the MIC and MBC values of the compounds at pH 4.0, 7.0, and 9.0 against four Gram-positive strains revealed high values for both the MIC and MBC at pH 4.0 (ranging from 0.98 to 125 μg/mL) and moderate values at pH 7.0 and 9.0, exposing strong antimicrobial activities in an acidic medium. An antioxidant activity analysis of the molecules was performed by using the DPPH (2,2-diphenyl-1-picrylhydrazyl) method, which showed high activity for the TSMT (N-(1-methyl-2H-tetrazol-5-yl)-N-(1,1-dioxo-1,2-benzisothiazol-3-yl) amine, 7) derivative (90.29% compared to a butylated hydroxytoluene positive control of 61.96%). Besides, the general toxicity of the saccharin analogs was evaluated in an Artemia salina model, which displayed insignificant toxicity values. In turn, upon an assessment of cell viability, all of the compounds were found to be nontoxic in range concentrations of 0–100 μg/mL in H7PX glioma cells. The tested molecules have inspiring antimicrobial and antioxidant properties that represent potential core structures in the design of new drugs for the treatment of infectious diseases.
Alkali salts of 1-methyl-5-nitriminotetrazole - Structures and properties
Klap?tke, Thomas M.,Radies, Hendrik,Stierstorfer, J?rg
, p. 1343 - 1352 (2007)
Alkali salts of 1-methyl-5-nitriminotetrazole (1, 1-MeAtHNO2) are common intermediates in the synthesis of alkylated nitriminotetrazoles and their derivatives and can be used as brilliant coloring agents in modern pyrotechnics, due to their cations in combination with the high nitrogen contents. The structures of the crystalline state of A+ 1-MeAtNO 2-·x H2O (A = Li+, x = 1 (2), A = Na+ (3), A = K+ (4), A = Rb+ (5) and A = Cs+ (6), all x = 0) were determined using low temperature single crystal X-ray diffraction. In addition, the compounds were characterized using vibrational (IR and Raman) and multinuclear NMR spectroscopy (1H, 7Li, 13C, 14N, 15N), elemental analysis and differential scanning calorimetry (DSC). Since tetrazoles are known to be promising energetic materials, the heats of formation were calculated using experimentally determined heats of combustion obtained by bomb calorimetry. The sensitivities of all compounds were tested using the BAM drophammer and friction tester showing them to have no sensitivity neither against friction (1, a = 3.5152(3), b = 12.3308(9), c = 7.3381(5) A?, β = 92.068(7)°, V = 317.86(4) A?3, Z = 2, δ = 1.756 g cm-3; 3: monoclinic, P21/n, a = 3.6071 (2), b = 8.3254(5), c = 18.955(1) A?, β = 91.365(6)°, V = 569.07(6) A?3, Z = 4, δ = 1.939 g cm-3; 4: monoclinic, P21/c, a = 3.6310(1), b = 8.6487(2), c = 19.8598(5) A?, β = 94.945(2)°, V = 621.34(3) A?3, Z = 4, δ = 1.948 g cm-3; 5: monoclinic, P21/n, a = 8.7948(2), b = 10.1640(2), c = 15.0571(3) A?, β = 92.470(2)°, V = 1344.71(5) A?3, Z = 8, δ = 2.258 g cm-3; 6: monoclinic, P21/n, a = 6.3539(1), b = 13.4762(3), c = 8.2876(2) A?, β = 99.245(2)°, V = 700.42(3) A?3, Z = 4, δ = 2.618 g cm-3.
Synthesis and antileishmanial activity of 1,2,4,5-tetraoxanes against leishmania donovani
Cabral, Lília I.L.,Pomel, Sébastien,Cojean, Sandrine,Amado, Patrícia S.M.,Loiseau, Philippe M.,Cristiano, Maria L.S.
supporting information, (2020/02/11)
A chemically diverse range of novel tetraoxanes was synthesized and evaluated in vitro against intramacrophage amastigote forms of Leishmania donovani. All 15 tested tetraoxanes displayed activity, with IC50 values ranging from 2 to 45 μm. The most active tetraoxane, compound LC140, exhibited an IC50 value of 2.52 ± 0.65 μm on L. donovani intramacrophage amastigotes, with a selectivity index of 13.5. This compound reduced the liver parasite burden of L. donovani-infected mice by 37% after an intraperitoneal treatment at 10 mg/kg/day for five consecutive days, whereas miltefosine, an antileishmanial drug in use, reduced it by 66%. These results provide a relevant basis for the development of further tetraoxanes as effective, safe, and cheap drugs against leishmaniasis.
Solvent-free oxidation of benzyl alcohols catalysed by a tetrazole-saccharinate Zn(II) complex under microwave radiation: The role of the ligand and the reaction mechanism
Cristiano, M. Lurdes S.,Fernandes, André L.,Frija, Luís M. T.,Pombeiro, Armando J. L.
, (2020/07/27)
Herein we present an efficient methodology for the microwave-assisted peroxidative oxidation of benzyl alcohols to the corresponding aldehydes by using a novel and stable tetrazole-saccharinate zinc(II) catalyst, along with some insights into the reaction mechanism. This methodology is distinguished by the use of easily available and cheap reagents on the genesis of the zinc catalyst, mild reaction conditions, very short reaction periods (5–20 min) and no need to add an organic solvent. Furthermore, the use of TBHP (70percent. aq.) as oxidizing agent turn this protocol a convenient one for benzyl alcohol oxidation in yields up to 98percent.
NEW ENDOPEROXIDE COMPOUNDS, PROCESS FOR OBTAINING THEM AND USES THEREOF FOR CONTROL OF PERKINSIOSIS IN BIVALVES
-
Page/Page column 22-23, (2020/12/11)
The present invention relates to new endoperoxide compounds and compositions, and to a process for producing them for prophylaxis and control of perkinsiosis in bivalves. Endoperoxide compounds with biological activity against Perkinsus olseni include 13
2-Methyl-substituted monotetrazoles in copper(ii) perchlorate complexes: manipulating coordination chemistry and derived energetic properties
Zeisel, Lukas,Szimhardt, Norbert,Wurzenberger, Maximilian H. H.,Klap?tke, Thomas M.,Stierstorfer, J?rg
supporting information, p. 609 - 616 (2019/01/10)
A proposed correlation between coordination chemistry and deduced energetic properties (thermal behaviour, and sensitivities towards mechanical and optical stimuli) of copper(ii) complexes is investigated. Starting from a system comprising Cu(ClO4)2 and either of the ligands 2-methyl-5-aminotetrazole (1, 2-MAT) or 2-methyl-5H-tetrazole (2, 2-MTZ), typically altered parameters like the metal(ii) centre, ligand, or counterion were predefined. Instead, solely slight changes in ligand concentration and the solvent system were implemented in order to provide an insight into structure-property relationships of energetic coordination compounds (ECC) of this type. As a result, five highly energetic complexes [Cu(H2O)2(2-MAT)4](ClO4)2·H2O (3), [Cu(H2O)2(2-MAT)4](ClO4)2 (4), [Cu(H2O)2(2-MAT)4](ClO4)2·2 2-MAT (5), [Cu(ClO4)2(H2O)2(2-MAT)2] (6), and [Cu(H2O)2(2-MTZ)4](ClO4)2 (7) were synthesized and, except for 5, elaborately characterized. Besides structural elucidation via X-ray diffraction, NIR-spectroscopy, differential thermal analysis (DTA), standard sensitivity measurements (impact, friction, and electrostatic discharge), UV/vis-spectroscopy, and optical initiation experiments were conducted to deduce a precise relationship between coordination chemistry and the consequential energetic characteristics of these complexes.
Substituent-dependent coordination modes of 1-methyl-5-R-tetrazoles in their cupric chloride complexes
Voitekhovich, Sergei V.,Lyakhov, Alexander S.,Matulis, Vadim E.,Ivashkevich, Ludmila S.,Ivashkevich, Oleg A.
, p. 100 - 110 (2019/02/19)
A series of cupric chloride complexes with 1-methyl-5-R-tetrazole ligands, where R = NH2, t-Bu, Ph, MeS, CH[dbnd]CH2, MeSO2, were synthesized by interaction of CuCl2·2H2O with the above ligands LNH2, LtBu, LPh, LMeS, LVin, and LMeSO2, respectively. The obtained complexes [Cu(LNH2)3Cl2]·H2O (1), [Cu(LtBu)2Cl2] (2), [Cu(LPh)2Cl2] (3), [Cu(LMeS)2Cl2] (4), [Cu(LVin)Cl2]n (5), and [Cu(LMeSO2)(H2O)Cl2]n (6) were characterized by single crystal X-ray analysis. The effect of C5-substituent on coordination modes of tetrazole ligands and structural motifs of complexes was observed. Complexes 1–4 are mononuclear, with the tetrazole ring N4 coordination. Complex 5 presents 1D coordination polymer, formed at the expense of triple bridge between two neighboring copper(II) cations (double chlorido bridge and the tetrazole ring N3,N4-bridge). In 6, being also 1D coordination polymer, coordination chains are composed of alternating Cu(LMeSO2)2 and Cu(H2O)2 fragments linked by double chlorido bridges. Ligand LMeSO2 shows N3 coordination, being rare among 1,5-disubstituted tetrazoles. The influence of the nature of C5 substituents on coordination features of the obtained complexes is discussed by using quantum-chemical calculations of the electronic structure and basicity of the ligands.
