Your browser doesn't support javascript.
loading
Halogen bonding properties of 4-iodopyrazole and 4-bromopyrazole explored by rotational spectroscopy and ab initio calculations.
Cooper, Graham A; Medcraft, Chris; Littlefair, Josh D; Penfold, Thomas J; Walker, Nicholas R.
Afiliação
  • Cooper GA; Chemistry-School of Natural and Environmental Sciences, Newcastle University, Bedson Building, Newcastle-upon-Tyne NE1 7RU, United Kingdom.
  • Medcraft C; Chemistry-School of Natural and Environmental Sciences, Newcastle University, Bedson Building, Newcastle-upon-Tyne NE1 7RU, United Kingdom.
  • Littlefair JD; Chemistry-School of Natural and Environmental Sciences, Newcastle University, Bedson Building, Newcastle-upon-Tyne NE1 7RU, United Kingdom.
  • Penfold TJ; Chemistry-School of Natural and Environmental Sciences, Newcastle University, Bedson Building, Newcastle-upon-Tyne NE1 7RU, United Kingdom.
  • Walker NR; Chemistry-School of Natural and Environmental Sciences, Newcastle University, Bedson Building, Newcastle-upon-Tyne NE1 7RU, United Kingdom.
J Chem Phys ; 147(21): 214303, 2017 Dec 07.
Article em En | MEDLINE | ID: mdl-29221380
The combination of halogen- and hydrogen-bonding capabilities possessed by 4-bromopyrazole and 4-iodopyrazole has led to them being described as "magic bullets" for biochemical structure determination. Laser vaporisation was used to introduce each of these 4-halopyrazoles into an argon gas sample undergoing supersonic expansion prior to the recording of the rotational spectra of these molecules by chirped-pulse Fourier transform microwave spectroscopy. Data were obtained for four isotopologues of 4-bromopyrazole and two isotopologues of 4-iodopyrazole. Isotopic substitutions were achieved at the hydrogens attached to the pyrrolic nitrogen atoms of both 4-halopyrazoles and at the bromine atom of 4-bromopyrazole. The experimentally determined nuclear quadrupole coupling constants, χaa(X) and χbb(X)-χcc(X), of the halogen atoms (where X is the halogen atom) of each molecule are compared with the results of the ab initio calculations and those for a range of other halogen-containing molecules. It is concluded that each of 4-bromopyrazole and 4-iodopyrazole will form halogen bonds that are broadly comparable in strength to those formed by CH3X and CF3X.

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Idioma: En Revista: J Chem Phys Ano de publicação: 2017 Tipo de documento: Article País de afiliação: Reino Unido

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Idioma: En Revista: J Chem Phys Ano de publicação: 2017 Tipo de documento: Article País de afiliação: Reino Unido