| Autor: |
José Sordo, Ángeles Touceda, Javier Ellena, José S. Casas, María S. García-Tasende, Saulo Vázquez Rodríguez, Agustín Sánchez, Eduardo E. Castellano |
| Rok vydání: |
2007 |
| Předmět: |
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| Zdroj: |
Polyhedron. 26:4228-4238 |
| ISSN: |
0277-5387 |
| Popis: |
The reaction of lead(II) acetate in methanol with thiosemicarbazones derived from β-keto esters and β-keto amides (HTSCs) afforded two lead(II) thiosemicarbazonates and numerous homoleptic ([PbL 2 ]) and/or heteroleptic ([Pb(OAc)L]) complexes containing deprotonated pyrazolones L − formed by metal-induced cyclization of the starting HTSC ligands. All the complexes isolated were characterized by IR spectroscopy in the solid state and by 1 H and 13 C NMR spectroscopy in DMSO solution; in addition, crystals containing [Pb(L 6 ) 2 ] and [Pb(L 7 ) 2 ] were examined by X-ray crystallography. [Pb(L 6 ) 2 ] · 0.5H 2 O · 0.3MeOH (HL 6 = 4-ethyl-2,5-dihydro-3-methyl-5-oxo-1 H -pyrazole-1-carbothiamide) showed three types of molecule with significant structural differences that appear to be determined by packing interactions. In all three molecules the Pb⋯Pb distances are very short [3.6096(8)–3.7562(8) A], but density-functional-theoretic calculations at the B3LYP level do not support the existence of Pb–Pb bonds. In [Pb(L 7 ) 2 ] (HL 7 = N -ethyl-2,5-dihydro-3-methyl-5-oxo-1 H -pyrazole-1-carbothiamide) all the molecules are of a single type, and they are linked in a three-dimensional network by weak intermolecular Pb⋯O bonds. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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