SYNTHESIS AND CHARACTERIZATION OF OXIMES LIGANDS AND THIOSEMICARBAZONES AND THEIR COMPLEXES / SÍNTESE E CARACTERIZAÇÃO DE LIGANTES OXIMAS E TIOSSEMICARBAZONAS E SEUS COMPLEXOS

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

This research shows the synthesis and characterization of five ligands and four complexes derived from oximes and thiosemicarbazones. It analyses the crystalline/molecular structures determined by X-ray difraction in monocrystals: the ligand 4- phenylthiosemicarbazone-isatin (Ligand 5), the complexes pyridine-salicylaldehyde-4- phenylthiosemicarbazone of Ni(II) (Complex 1), and the bis-4-phenylthiosemicarbazoneisatin the Pb(II) (Complex 2). The structure of Ligand 5 crytallizes in the monoclinic system, space group P21/c, with the cell parameters a=6,3227(2) Å, b=15,7973(7) Å, c=14,4572(6) Å, = 93,9330(10), V=1440,61(10) Å3 , Z=4. The refinement of the structure converges to the final discordance indexes R1 = 0,0520, wR2 = 0,1471. We have also observed the occurrence of intermolecular interactions of the type classic hydrogen bonds [N18−H3×××O1 2,907(2)Å], with the formation of dymer structures interrelated by symmetry within the crystalline cell. In the crystal structure of Complex 1, I have observed NC=4, and square plane coordination geometrics, where the ligand salicyladehyde-4-phenilsemicarbazone behaves as the tridentate quelating. In order to complete the coordenation sphere of the metallic center, there is a pyridine molecule. The structure crystallizes in the monoclinic system, space group P21/m, with cell parameters a = 12,8211(2) Å, b = 5,73370(10) Å, c = 23,9950(4) Å, = 101,0910(10), V = 1730,98(5) Å3, Z=3, and final discordance indexes R1= 0,0320, wR2 = 0,0888. Complex 1 presents intermolecular interactions of the type [N(3)-H(3)---S(1) =3,5838(17), N(3)H(3A)---S(1) = 160,91(19)], forming dymer structures and non-classic intramolecular hydrogen bonds of the type [C(10)-H(10)---N(2) = 2,838(2) and C(10) H(10)---N(2) = 122]. The crystalline structure of Complex 2 presents two independent forms (one with the center represented by Pb 1 and another represented by Pb2). For unit Pb, there is the compound formed by two units of Ligand 5 which behaves as the tridentate quelating, and the coordination sphere is completed by intermolecular interactions of the type h2-arene and by a bond polarized with the O1 of the neighbouring molecule; it gives NC=9 to ion Pb1. Unit Pb2 presents just the two coordinated units of Ligand 5 giving it NC=6. The structure crystallizes in the monoclinic system, space group C2/c, cell parameters a=37,9747(6) Å, b= 9,51280(10) Å, c= 31,4378(5) Å, = 125,951(2), V= 9193,5(2) Å3, Z=4, and final discordance indexes R1 = 0,0643, wR2 = 0,1227.

ASSUNTO(S)

hydrogen bonds oximas e tiossemicarbazonas compostos de coordenação ligações de hidrogênio oximes and thiosemicarbazone coordination compounds quimica inorganica

ACESSO AO ARTIGO

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