Complexes of main-group elements containing stereochemically active lone pairs: the crystal structures of [Tl(TpAn)] {TpAn=tris[3-(2-methoxyphenyl)pyrazol-1-yl]hydroborate} and [Pb(TpPy)(NO3)]·0.5Et2O {TpPy = tris[3,-(2-pyrdyl)pyrazol-1-yl]hydroborate}

Autor: John C. Jeffery, Karen L. V. Mann, Jon A. McCleverty, Michael D. Ward, Peter L. Jones
Rok vydání: 1997
Předmět:
Zdroj: Polyhedron. 16:2435-2440
ISSN: 0277-5387
DOI: 10.1016/s0277-5387(96)00573-6
Popis: The new podand ligand tris[3-(2-methoxyphenyl)pyrazol-1-yl]hydroborate (TpAn) has been prepared and the crystal structure of [Tl(TpAn)] determined. The metal ion is in a trigonal pyramidal geometry arising from the three pyrazolyl N-donors, with the lone pair of the TlI ion in the fourth position of the tetrahedron of electron pairs. There is also a weak but significant interaction with one of the anisyl oxygen atoms ( Tl · O = 3.018 A ), and the displacement of the metal ion towards this oxygen atom results in a noticeable lengthening of the TlN(pyrazolyl) bond which lies approximately trans to it (2.70 A, compared with 2.54 A for the other two TlN bonds). The crystal structure of [Pb(TpPy)(NO3)]·0.5Et2O shows that the PbII ion has four strong interactions (with the pyrazolyl nitrogen atoms and one of the nitrate oxygen atoms; range of bond lengths 2.49–2.67 A) and four weak ones (with the pyridyl nitrogen atoms and the other nitrate oxygen atom; range of bond lengths 2.80–2.99 A). If only the four stronger interactions are considered, the irregular coordination sphere of the PbII ion has an obvious gap in it which is the site of the stereochemically active long pair.
Databáze: OpenAIRE
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