Pujales Paradela R (2018)
Publication Status: Published
Publication Type: Journal article, Original article
Publication year: 2018
Publisher: ROYAL SOC CHEMISTRY
Book Volume: 47
Pages Range: 13830-13842
Journal Issue: 39
DOI: 10.1039/c8dt02602e
We report a detailed study of the structure of the [Bi(DO3A)] complex both in the solid state and in solution. The X-ray crystal structure of [Bi(DO3A)] evidences the octa-coordination of the Bi(iii) ion, which is directly coordinated to the four nitrogen atoms of the cyclen unit and three oxygen atoms of the carboxylate groups. The octa-coordination is completed by an oxygen atom of a neighboring carboxylate group, which bridges Bi(iii) ions thanks to (2)-(1):(1) coordination, resulting in the formation of a coordination polymer. The Bi(iii) ion presents a twisted-square antiprismatic (TSAP) coordination geometry associated with the ()/() enantiomeric pair. A computational DFT study indicates that the 6s(2) lone pair of Bi(iii) is stereochemically active in [Bi(DO3A)] and most of the cyclen-based complexes reported in the literature. Depending on the spatial arrangement of the donor atoms of the ligand the lone pair points in different directions, so that Bi(iii) can easily accommodate different coordination environments. In solution the [Bi(DO3A)] complex exists as a monomeric complex, as demonstrated by DOSY measurements. The stability constant of the [Bi(DO3A)] complex, determined by using batch spectrophotometric titrations, was found to be rather high (logK = 26.85(5)). The complex presents characteristic absorption in the UV spectrum at 299 nm (epsilon = 8770 M-1 cm(-1)) that was attributed to the Bi(iii)-centered 6p 6s band on the basis of TDDFT calculations. Spectrophotometric titrations reveal weak binding of different anions to the [Bi(DO3A)] complex, with association constants of K-11 = 3.55(8), 3.09(7), 6.2(1) and 2.19(5) for Cl-, Br-, I- and N-3(-), respectively.
APA:
Pujales Paradela, R. (2018). On the consequences of the stereochemical activity of the Bi(iii) 6s(2) lone pair in cyclen-based complexes. The [Bi(DO3A)] case. Dalton Transactions, 47(39), 13830-13842. https://dx.doi.org/10.1039/c8dt02602e
MLA:
Pujales Paradela, Rosa. "On the consequences of the stereochemical activity of the Bi(iii) 6s(2) lone pair in cyclen-based complexes. The [Bi(DO3A)] case." Dalton Transactions 47.39 (2018): 13830-13842.
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