Synthesis and spectroscopic properties of new bis-tetrazoles

Abstract

Syntheses of N,N′-phenyltetrazole podands link with aliphatic chains containing oxygen, nitrogen and sulphur atoms, are described. The complexing properties of these compounds towards metal cations (Fe2+, Cu2+, Zn2+, Co2+, Ni2+) were investigated by absorption and infrared spectroscopy. The UV–Vis titrations were performed to estimate the stability constant values of the respective complexes with Cu2+ ion. Changes in UV–Vis absorption spectra and IR spectra of compound 6 under various concentrations of Cu2+ ion in methanol suggest formation of very unstable complex. The structure of ligand 2 has been deduced by X-ray crystallography.

Transient Catalytic Activity of a Triazole‐based Gelator Regulated by Molecular Gel Assembly/Disassembly

“…This method has been widely applied to in the study of metal‐ligand interactions in order to investigate possible metal‐ligand charge transitions (MLCT) . The increase on the absorbance with increasing copper(I) addition suggest complexation of the metal to the triazole product (See SI), as previously observed for other triazole‐based ligands …”

“…[30][31][32] The increase on the absorbance with increasing copper(I) addition suggest complexation of the metal to the triazole product (See SI), as previously observed for other triazole-based ligands. [30,33] Furthermore, the accentuated contrast of the crystals belonging to the final product in the TEM pictures ( Figure 10 < E xfigr10 > ) also suggest Cu(I) coordination by the reaction product. On the other hand, if Cu(I) is added on the 3 rd catalytic cycle in a common batch together with the reactants, the catalytic activity could still be maintained, although on the 4 th run a decay on catalytic performance is observed.…”

Synthesis and antitumor evaluation of some new derivatives and fused heterocyclic compounds derived from thieno[2,3‐b]pyridine: Part 2

“…[22] Elemental analysis with spectral data (IR, 1 H NMR, and 13 C NMR) verified the structure of compound 11. [23,24] Upon treatment of compound 11 with an excess amount of triethyl orthoformate, [25] the ring closure has occurred to provide the respective triazolo[4,3-a]pyrimidine derivative 13. The IR spectrum of compound 12 revealed an absorption band at 2160 cm −1 assigned to the azide function, in addition to strong band characteristic for 1,5-disubstituted tetrazole ring at 1575 cm −1 , as well as an absorption band due to (N-N═N) moiety at 1338 cm −1 .…”

“…These spectroscopic data are similar to those found for 1,5-disubstituted tetrazole in the literature. [23,24] Upon treatment of compound 11 with an excess amount of triethyl orthoformate, [25] the ring closure has occurred to provide the respective triazolo[4,3-a]pyrimidine derivative 13. Formation of pyrimido[2,1-c][1,2,4]triazinone derivative 14 was achieved through the reaction of compound 11 with ethyl 2-chloroacetoacetate in the presence SCHEME 2 Reagents and conditions: (i) NH 2 CH 2 CH 2 NH 2 /CS 2 , W.B.…”

Síntesis de tetrazoles 1-sustituídos como precursores de MOFs

“…Figura 14.Recientemente, Pazik y Skwierawska34 reportaron la síntesis de una serie de siete ligantes bis-tetrazólicos en los que los tetrazoles están enlazados a anillos aromáticos, los cuales a su vez están conectados mediante cadenas que contienen diferentes heteroátomos (N, O y S) en sus estructuras (Figura 15) vía una reacción de heterociclación como paso final de una estrategia de tres pasos para el caso de los ligantes 39 a 43; y dos para los ligantes 44 y 45, para introducir los tetrazoles 1-sustituídos como sitios de coordinación, obteniendo rendimientos de buenos a excelentes (45 -99%). Posteriormente, se estudió la síntesis de los complejos formados con los ligantes y diversos cationes metálicos [Fe(II), Cu(II), Zn(II), Ni(II) y Co(II)].…”