Back to the Coordination Modes of the Thiosemicarbazonate Chain: New Insights from Diorganolead(IV) and Lead(II) Derivatives of Isatin-3-thiosemicarbazone

摘要: The syntheses and characterizations of the new heteroleptic complexes [PbPh2(OAc)(N2-L1)]•MeOH•EtOH, [PbPh2(OAc)(N3-L2)]•H2O, [Pb(OAc)(N2-L1)], [Pb(OAc)(N3-L 1)]•3H2O [Pb(OAc)(N2-L2)] {HL1 = isatin-3-thiosemicarbazone, HL2 isatin-3-(N 1-methylthiosemicarbazone); N2-Lx thiosemicarbazonate bound through O,S hydrazinic [N(2)] nitrogen atom; N3-Lx iminic [N(3)] atom} are described. single-crystal X-ray structures HL2, [PbPh2(OAc)(N2-L1)] •MeOH•EtOH, [PbPh2(OAc)(N3-L2)] •H2O, [Pb(OAc)(N2-L1)] [Pb(OAc)(N 3-L1)]•3H2O have been solved. organometallic compounds [PbPh2(OAc)(N2-L 1)]•MeOH•EtOH [PbPh2(OAc)(N 3-L2)]•H2O a roughly similar distorted bipyramidal pentagonal stereochemistry, with apical phenyl groups both O,Nx,S-coordinated Lx- anisobidentate AcO- ligands in equatorial plane. In [PbPh2(OAc) (N2-L1)]•MeOH•EtOH, (N2-L 1)- ligand forms four- six-membered chelate ring metal, whereas PbPh2(OAc)(N3-L 2)]•H2O two rings formed by (N 3-L2)- five-membered. PbII complexes, 3-L1)], which were isolated from same solution, linkage isomers. These rather irregular stereochemistry that suggests presence stereochemically active lone electron pair; (L1)- is O,N2,S-coordinated [Pb(OAc)(N3-L1)] this O,N3,S-coordinated. Analyses all these systems solution 1H 13C NMR spectroscopy showed during synthesis kinetically controlled O,N2,S isomer first due to rigidity ligand. If compound remains slow partial evolution O,N3,S occurs. DFT calculations predict slightly more stable than gas phase DMSO solution. also modelled for isomers close those obtained diffraction studies. Solid state studies indicated that, title derivatives, thiosemicarbazone chain initially N2,S coordination, but evolves time form N3,S-linkage isomer. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.