Synthesis, characterization and crystal structures of the first pentacoordinate nickel(II) complexes containing N,S-donor ligands †
2000; Issue: 4 Linguagem: Inglês
10.1039/a907367a
ISSN1470-479X
AutoresM. Dolores Santana, Gabriel Garcı́a, Antonio Rufete, Carmen Ramı́rez de Arellano, G. López,
Tópico(s)Crystal structures of chemical compounds
ResumoBy reaction of the hydroxo nickel complexes [Ni([12]aneN3)(μ-OH)]2+2 ([12]aneN3 = 2,4,4-trimethyl-1,5,9-triazacyclododec-1-ene ([12]aneN3-mc1) and its 9-methyl derivative ([12]aneN3-mc2)) with heterocyclic-2-thiones in acetone, the pentacoordinate nickel(II) complexes [Ni([12]aneN3)(LL′)]+ (LL′ = py2S (pyridine-2-thionate) 1, 5; pym2S (pyrimidine-2-thionate) 2, 6; bzimSH (benzimidazole-2-thionate) 3, 7; bztzS (benzothiazole-2-thionate) 4, 8) have been prepared. The X-ray diffraction study on 5, 6 and 7 shows that the thionate is bonded to nickel atom as chelating η2-N,S ligand, the nickel atom being in a distorted square pyramidal geometry. Complex 7 is the first structurally characterized example of a 1,3-benzimidazole-2-thionate derivative acting as a chelating ligand. The 2-D NOE technique (NOESY) allowed us to assign the isotropically shifted resonances due to coordinated thionates. Elemental analysis as well as IR and UV-VIS spectroscopic studies have also been used to aid structural characterization.
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