Premium
Structural Diversity in Thallium Chemistry. Part V
Author(s) -
Linden Anthony,
Petridis Alexander,
James Bruce D.
Publication year - 2003
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.200390070
Subject(s) - chemistry , pyridinium , bromide , raman spectroscopy , stoichiometry , thallium , crystallography , hydrogen bond , trigonal bipyramidal molecular geometry , crystal structure , ion , salt (chemistry) , inorganic chemistry , molecule , medicinal chemistry , organic chemistry , physics , optics
Abstract From thallium(III) bromide solution, the unsubstituted pyridinium cation yields a complex ( 1 ) with the [Tl 2 Br 9 ] 3− anionic stoichiometry. The Raman spectrum and single‐crystal X‐ray crystallographic analysis showed that the salt contains independent [TlBr 4 ] − and bromide anions. A variety of mono‐ and disubstituted pyridinium cations were also employed in similar syntheses. The 2‐bromopyridinium cation gave a salt 2 with [TlBr 5 ] 2− stoichiometry, but the crystal structure revealed very weakly interacting [TlBr 4 ] − and bromide anions with a Tl ⋅⋅⋅Br − distance of 4.1545(6) Å. The 2‐(ammoniomethyl)pyridinium and 2‐amino‐4‐methylpyridinium cations yielded complexes containing [TlBr 5 ] 2− ( 3 ) and [TlBr 4 ] − ( 4 ) species, respectively, which were confirmed by Raman spectroscopy and X‐ray crystallographic analyses. For 3 , the [TlBr 5 ] 2− anion has a highly distorted trigonal bipyramidal conformation with one long axial Tl ⋅⋅⋅Br bond of 3.400(2) Å. Microanalytical results in conjunction with Raman spectra from a further five salts confirmed that they all contain the simple [TlBr 4 ] − anion. NH ⋅⋅⋅Br Hydrogen bonds clearly influence the nature of the anionic species obtained in these systems.