¹³C and ¹⁵N nuclear magnetic resonance studies of selected tetrazoles: Relationships with the chemistry of tetrazoles

Abstract

sodium tetrazolate salts, 1,sand 2,s-disubstituted tetrazoles, bitetrazoles, and cobalt(II1) tetrazolate complexes of the type (PBu3")Co(DH),(5-R-tetrazolate), where DH is the monoanion of dimethylglyoxime.The "N chemical shifts have been analysed with respect to structure, substituent effects, electron density as determined by molecular orbital calculations, Brensted acidity, Lewis basicity and nucleophiiicity of the nitrogen atoms in the ambidentate tetrazoles.

A New 5,5′‐Bitetrazole Thorium(IV) Compound: Synthesis, Crystal Structure and Quantum Chemical Investigation

“…Generally, the finding of discrete Th 2 O 16 moieties with absent Th IV -BT contacts is in line with the recent observation of the coordination behaviour of BT 2-in the analogue Tb III and Er III systems: [12] Tb III , Er III , and Th IV have -in a ninefold-coordinated scenario -comparable ionic radii of 109, 106, and 109 pm, [16] respectively, and must be regarded as strong and hard Lewis acids, thus favouring H 2 O over BT 2- [9] From the higher positive charge on Th IV it appears natural that, in going beyond the Ln III series, one finds a salt-like Th IV -BT 257 (4) [a] This work.…”

“…[8] Recently, our group reported on the 5,5Ј-bitetrazole coordination chemistry of a number of trivalent 4f element ions. [9] Generally, the 5,5Ј-bitetrazolate dianion BT 2- [10][11][12] and related tetrazolyl systems are interesting candidates for rich coordination chemistry: For example, BT 2-contains eight N atoms, being able to act as mono-, bi-, tri-or tetradentate ligand (cf. Scheme 1), and might therefore give rise to mononuclear, binuclear, or oligonuclear complexes (coordination polymers), as well as the formation of one-, two-, or three-dimensional networks in the solid state.…”

Polynuclear branched tetrazole systems. 3. Acidity of α,ω-ditetrazol-5-ylalkanes

“…This circumstance permits the suggestion of a related character for the solvation of each compound in the given binary solvent [8]. It was shown previously by the authors of [9] that for 5-substituted tetrazoles a linear dependency exists between the chemical shift of the signals of the endocyclic carbon atom of the tetrazole ring in the 13 C NMR spectra and pK a . We have also found analogous correlation dependencies (1), (2) for the sizes of pK a 1 and pK a 2 of compounds 1-5.…”

Azide Chemistry – An Inorganic Perspective, Part II[‡][3+2]‐Cycloaddition Reactions of Metal Azides and Related Systems

“…[291] An attempt to prepare 5,5'-bistetrazolate from (CN) 2 and CsN 3 in excess was unsuccessful; [289] this dianion can be synthesized from NaCN and NaN 3 under oxidizing conditions (MnO 2 , Cu 2+ ), however. [228] A rather dubious paper claiming multiple cycloaddition between the cyano ligands in [Fe(CN) 5 …”

“…[171,227] Nelson at first made use of the changes in the appearance of the 1 H NMR spectra upon heating equilibrium mixtures of cis/trans-and N 1 /N 2 -isomers for their identification; here the resonances of the higher energy isomers -trans and N 1 -increased in intensity at the expense of those of the cis and the N 2 -bonded species. [151] Later he was able to distinguish the isomers of disubstituted tetrazoles from one another by simply analyzing the natural abundance 15 N NMR spectra, which for the 1,5-substitution pattern exhibit a high field resonance [152,228] Particularly favourable types of tetrazoles which allow for the unambiguous determination of their binding site from the 1 H and 13 C NMR spectra of their metal complexes are those with aryl substituents in the 5-position. Not only that according to Butler [229] there are also markedly larger separations between the chemical shifts of the ortho-and meta-H atoms (δH o -δH m ) as well as of the respective C atoms (δC 3' -δC 2' ) when the tetrazole is N 2 -coordinated.…”