Synthesis, solution thermodynamics, and X-ray study of CuII [12]metallacrown-4 with GABA hydroxamic acid: an unprecedented crystal structure of a [12]MC-4 with a gamma-aminohydroxamate |
| |
Authors: | Tegoni Matteo Ferretti Luca Sansone Francesco Remelli Maurizio Bertolasi Valerio Dallavalle Francesco |
| |
Affiliation: | Dipartimento di Chimica Generale ed Inorganica, Chimica Analitica, Chimica Fisica, Università degli Studi di Parma, Viale G.P. Usberti 17A, 43100 Parma, Italy. |
| |
Abstract: | The solution equilibria of gamma-aminobutanehydroxamic acid (GABAha) with H+ and Cu2+ were investigated by potentiometry, titration calorimetry, spectrophotometry, NMR spectroscopy, and ESI-MS. The thermodynamic parameters of the CuII [12]metallacrown-4 obtained for GABAha were compared with those of the corresponding complexes of (S)-alpha-Alaha and beta-Alaha. The stability (-DeltaG0) sequence was beta-Alaha>alpha-Alaha>GABAha, whereas the order of formation enthalpies (-DeltaH0) was beta-Alaha>GABAha>alpha-Alaha. These data were interpreted on the basis of the dimensions of the chelate rings and the planarity of the metallamacrocycles. The CuII [12]metallacrown-4 ([12]MC-4) complex of GABAha was isolated and its crystal structure, which is the first reported for a [12]MC-4 of a gamma-aminohydroxamic acid, fully supports the structural features interpreted from the thermodynamic data. |
| |
Keywords: | aminohydroxamic acids crown compounds metallacycles structure elucidation thermodynamics |
本文献已被 PubMed 等数据库收录! |
|