High-level ab initio electronic structure calculations, including extrapolations to the complete basis set (CBS) limit, were performed, and highly precise relative energies of five-member N-heterocycles were determined. Nitrogen-containing heterocycles studied included tautomers of tetrazole (CH(2)N(4)) and triazoles (C(2)H(3)N(3)). Valence focal-point analysis of 1H-tetrazole, 2H-tetrazole, 5H...

A study of the effect of the tetrazole moiety, a cis-amide bond surrogate, on the Cu(II) coordinating properties of oligopeptides is reported. Insertion of the tetrazole moiety Psi[CN(4)] into the peptide sequence of [D-Ala(2)]deltorphin I changes considerably the coordination ability of the peptide. Potentiometric and spectroscopic results show that if the tetrazole moiety is in a suitable pos...

The aim of the investigation was to establish the chelating ability of a new proctolin analogue of the sequence Arg-Tyr-LeuPsi[CN(4)]Ala-Thr towards copper(II) ions. The insertion of the tetrazole moiety into the peptide sequence has considerably changed the coordination ability of the ligand. Potentiometric and spectroscopic (UV-Vis, CD, EPR) results indicate that the incorporation of 1,5-disu...

The ongoing study is a Ugi-azide four-component reaction for the synthesis of 1,5-disubstituted tetrazole(1,5-DST), which involves an aldehyde, different amines, isocyanides, and as azide’s source Trimethylsilylazide (TMSN3), in water solvent using catalyst tetradecyltrimethylammonium bromide (TTAB) with load (10% mole), provides hydrophobic micellar site. This approach step toward green chemis...

This combined experimental, theoretical and comparative study details the syntheses and chemical characterisation of two new energetic polynitromethyl tetrazole derivatives, namely, 2-(2-nitro-2-azapropyl)-5-(trinitromethyl)-2 H-tetrazole and its fluorine-containing analogue 2-(2-nitro-2-azapropyl)-5-(fluorodinitromethyl)-2 H-tetrazole. Their crystal structures and energetic behaviour are compa...

The title compound, C(7)H(13)N(5), a tetrazole analogue of betaines, exists as a zwitterion, with the H atom of the tetrazole ring being transferred to the piperidine ring N atom. The tetrazole ring symmetry is close to C(2v), which suggests strong charge delocalization in the N-C-N fragment of the ring. There are classical hydrogen bonds in the structure which are responsible for the formation...

The metal-organic framework [Cd15(5MT)18(OH)4(SO4)4] (5-MT = 5-methyl-1H-tetrazole) with an unprecedented Cd(3)(micro3-OH)(micro3-SO4) core and two kinds of tetrazole coordination modes was formed by self-assembly and in situ synthesis of the 5-MT tetrazole ligand; the structure exhibits an unusual 3(9) x 4(12) x 5(15) topological network and shows reversible shrinkage and expansion in a crysta...

Bio-orthogonal chemistry has been widely used for conjugation of polymer molecules to proteins. Here, we demonstrate the conjugation of polyethylene glycol (PEG) to bovine beta-lactoglobulin (BLG) by photo-induced cyclo-addition of tetrazole-appended PEG and allyl-modified BLG. During the course of the investigation, a significant side-reaction was found to occur for the conjugation of PEG-tetr...

The decomposition of 5-benzhydryl-1H-tetrazole in an N-methyl-2-pyrrolidone/acetic acid/water mixture was investigated under a variety of high-temperature reaction conditions. Employing a sealed Pyrex glass vial and batch microwave conditions at 240 °C, the tetrazole is comparatively stable and complete decomposition to diphenylmethane requires more than 8 h. Similar kinetic data were obtained ...

Development of a new improved and efficient process suitable for the large-scale production of Irbesartan has been described. The key steps are tetrazole formation from secondary amide for the preparation of the key intermediate 1-Benzyl-5-(4'-bromomethyl-biphenyl-2-yl)-1H-tetrazole (9), N-alkylation and debenzylation.