Negatively charged hydrogen-bonded chains formed by tetrazole

Brzeziński, Bogumił; Wojciechowski, Grzegorz; Zuńdel, Georg; Sobczyk, L.; Grech, E.

doi:10.1016/s0022-2860(99)00064-2

Cited by 10 publications

(10 citation statements)

References 15 publications

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“…NMR Measurements. 1 H, 13 C, and 19 F NMR spectra were recorded on a spectrometer at 300.075, 75.461, and 282.352 MHz, respectively, in 0.1 M CDCl 3 solutions, in 5 mm tubes. The chemical shifts were measured with respect to an internal standard (TMS for 1 H and 13 C NMR spectra; CFCl3 for 19 F NMR spectra δ 0.00 ppm).…”

Section: Methodsmentioning

confidence: 99%

“…6 The pK a values of the amidines DBU and DBN are 24.33 and 23.79, respectively. 6 Amidines and guanidines are very important agents in the deprotonation reactions of weak O-H, [8][9][10][11][12] N-H, [13][14][15] and C-H [16][17][18] acids, whereas after protonation all of them, except for MTBD, can form homoconjugated complexes. 19 Furthermore, in our previous papers we have demonstrated that MTBD can form hydrogen-bonded chains with phenols, [8][9][10][11][12]20,21 biphenols, and NH acids in nonpolar aprotic solvents as well as in the solid state.…”

Section: Introductionmentioning

confidence: 99%

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Reaction of Some Strong N-Bases with Chloropentafluorobenzene in the Presence of Water Molecules

2003

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Products of reactions between chloropentafluorobenzene and strong N-bases (DBN, DBU, TBD, and MTBD) in polar aprotic solvents and in the presence of water were isolated and identified by analytical and spectroscopic methods. The products of these dehydrohalogenation reactions are apropriate lactams, and if the TBD N-base is used, a condensation occurs with formation of benzimidazole derivative. All the products are not formed directly in the nucleophilic substitution by N-bases but after the hydrolyses of the N-bases with formation of amines known as hard nucleophiles.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Reaction of Some Strong N-Bases with Chloropentafluorobenzene in the Presence of Water Molecules

2003

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“…The tendency of tetrazoles to produce series of charged cluster peaks containing neutral tetrazole molecules has been noted in a different context before. 29 ion pairs that are solvent-separated. In all probability solvatophobicity may well be a major factor, and the greater lipophilicity of some of the heterocyclic acids compared to a carboxylate will have to be considered.…”

Section: Competition Experimentsmentioning

confidence: 99%

Binding interactions between 3-aryl-1,2,4-oxadiazol-5-ones and a trisimidazoline base

Reichert

Fröhlich

Ferguson

et al. 2001

J. Chem. Soc., Perkin Trans. 1

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The use of 1,2,4-oxadiazol-5-ones, a recently developed class of bioisosteric replacements for carboxylic acids in medicinal chemistry, as binding ligands in supramolecular complexes is reported and has been exemplified by the formation of non-covalent complexes between acidic 3-aryl-1,2,4-oxadiazol-5-ones and an imidazoline base, 1,3,5-tris(4,5-dihydroimidazol-2-yl)benzene 1. The X-ray crystal structure of complex 6d illustrates how the carbonyl oxygen and the nitrogen atom in the position α to the carbonyl group of the heterocyclic ligand are hydrogen-bonded to the NH groups of tris(imidazoline) 1. A combination of 1 H NMR dilution studies and electrospray mass spectrometry-based competition experiments shows that 1,2,4-oxadiazol-5-ones bind more strongly to receptor 1 than a comparable benzoate.

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“…Some systems with NH‚‚‚Nh -N‚‚‚HN were also already studied. [16][17][18][19] In ref 16 intermolecular and in refs 12, 17-19 intramolecular (NH‚‚‚N)bonds were investigated.…”

Section: Introductionmentioning

confidence: 99%

“…Vice versa hydrogen bonds with great proton polarizability in systems are indicated by these infrared continua. − Many systems with N + H···N ⇌ N···H + N bonds with great proton polarizability have been already studied. − In ref , it was shown that the infrared continua and hence the proton polarizability of the N + H···N ⇌ N···H + N hydrogen bonds are almost independent of the p K a of the N acceptors. Some systems with NH···N - ⇌ - N···HN were also already studied. − In ref intermolecular and in refs , −19 intramolecular (NH···N) - bonds were investigated.…”

Section: Introductionmentioning

confidence: 99%

Homoconjugated (NH···N)^- Hydrogen Bonds with Great Proton PolarizabilityFTIR and NMR Studies

Bauer¹,

Zuńdel²

2002

J. Phys. Chem. A

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Nine NH acids with pK a values between 0 and 8.57 were studied by FTIR spectroscopy in the middle and far-infrared region. In addition, NMR spectra were taken and a semiempirical AM1 analysis of the systems performed. The proton potential in the NH‚‚‚Nh -N‚‚‚HN hydrogen bonds is almost the same. The proton polarizability of these hydrogen bonds is almost independent of the pK a of the studied N acids. There is no relation between the position of the hydrogen bond vibration in the far-infrared region and the pK a of the N acids. Only with the pyrrol, the pyrazol, and the 4,( 5)-methylimidazol systems these hydrogen bonds are linear. With all other systems these hydrogen bonds are more or less strongly bent. The position of the hydrogen bond vibrations ν σ calculated with the AM1 procedure agrees well with the experimentally obtained values. The chemical shift of the hydrogen-bonded proton increases in proportion to the pK a values of the N acids.

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Negatively charged hydrogen-bonded chains formed by tetrazole

Cited by 10 publications

References 15 publications

Reaction of Some Strong N-Bases with Chloropentafluorobenzene in the Presence of Water Molecules

Reaction of Some Strong N-Bases with Chloropentafluorobenzene in the Presence of Water Molecules

Binding interactions between 3-aryl-1,2,4-oxadiazol-5-ones and a trisimidazoline base

Homoconjugated (NH···N)^- Hydrogen Bonds with Great Proton PolarizabilityFTIR and NMR Studies

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Negatively charged hydrogen-bonded chains formed by tetrazole

Cited by 10 publications

References 15 publications

Reaction of Some Strong N-Bases with Chloropentafluorobenzene in the Presence of Water Molecules

Reaction of Some Strong N-Bases with Chloropentafluorobenzene in the Presence of Water Molecules

Binding interactions between 3-aryl-1,2,4-oxadiazol-5-ones and a trisimidazoline base

Homoconjugated (NH···N)- Hydrogen Bonds with Great Proton PolarizabilityFTIR and NMR Studies

Contact Info

Product

Resources

About

Homoconjugated (NH···N)^- Hydrogen Bonds with Great Proton PolarizabilityFTIR and NMR Studies