Síntese, propriedades e investigação estrutural de 1,3-diariltriazenos e complexos com Ni(II), Pd(II), Pt(II) e Hg(II)

Although transition metal complexes with nitrogen coordination spheres involving monocatenated 1,3-diarylsubstituted triazenido ligands (ArNNNAr)−, have been investigated in the last decades, the structure of such compounds continues to attract the interest investigatiors. The synthesis of new triaz...

Nível de Acesso:openAccess
Publication Date:2006
Main Author: Visentin, Lorenzo do Canto lattes
Orientador/a: Hörner, Manfredo lattes
Banca: Filgueiras, Carlos Alberto Lombardi lattes, Casagrande Junior, Osvaldo de Lazaro lattes, Bordinhão, Jairo lattes, Fenner, Herton lattes
Format: Tese
Language:por
Published: Universidade Federal de Santa Maria
Programa: Programa de Pós-Graduação em Química
Department: Química
Assuntos em Português:
Áreas de Conhecimento:
Online Access:http://repositorio.ufsm.br/handle/1/4304
Citação:VISENTIN, Lorenzo do Canto. Synthesis, properties and structural investigation of 1,3-diariltriazenes and complexes with Ni(II), Pd(II), Pt(II) e Hg(II). 2006. 362 f. Tese (Doutorado em Química) - Universidade Federal de Santa Maria, Santa Maria, 2006.
Resumo Português:O estudo de complexos de coordenação com metais de transição, envolvendo pré-ligantes triazenos desperta interesse há muitas décadas. A síntese de moléculas derivadas do triazeno 1-3-diariltriazeno e seus complexos com Ni(II), Pd(II), (Pt)(II) e Hg(II) são tema de estudo neste trabalho. Triazenos são moléculas com pares de elétrons livres. Estes elétrons podem ser doados aos metais de transição formando complexos de coordenação. As estruturas dos compostos 3-(4-bromofenil)-1-(4-nitrofenil)triazeno, 3-(2-flúorofenil)-1-(4-nitrofenil)triazeno, 1-3-bis(4-azofenil)triazeno, estás moléculas foram caracterizadas por difração de raios-X em monocristal confirmando uma estereoquímica trans em torno da dupla ligação N=N na cadeia diazoamínica. Interações intermoleculares foram observadas na estrutura cristalina destas moléculas. Tratando cloreto de paládio (II) e trans-[Pd(Cl)2(PPh3)2] com 2 equivalentes de pré-ligantes triazenos (RN=N-NHR), derivados do 1-3-diariltriazeno mais coligantes piridina, menos para a reação com trans-[Pd(Cl)2(PPh3)2], formaram complexos de Pd(II) com geometria de coordenação quadrado-plana e isomeria geométrica trans. A reação entre cis-[Pt(Cl)2(DMSO)2] e os pré-ligantes triazenos mais coligantes piridina formaram complexos com geometria de coordenação quadradoplana e isômeros geométricos cis e trans. Interações intermolecular e intramolecular ocorrem nos complexos de platina(II). Também foi caracterizado um complexo cis de níquel(II) com ligantes triazenidos e co-ligantes piridina. Trabalhando com acetato de mercúrio(II) foi obtido um triazenido complexo em que existem interações Hg-areno-p formando dímeros. Estes ainda formam uma cadeia unidimensional através de ligações de hidrogênio-clássicas C−H×××O.
Resumo inglês:Although transition metal complexes with nitrogen coordination spheres involving monocatenated 1,3-diarylsubstituted triazenido ligands (ArNNNAr)−, have been investigated in the last decades, the structure of such compounds continues to attract the interest investigatiors. The synthesis of new triazenes derive 1-3-diariltriazenes and reaction with transition metal Ni(II), Pd(II), (Pt) and Hg(II) is the subject of this work. Triazenes are molecules with free electron pairs. These electron pairs can be donors to the transition metal for the formation of coordination complexes. The crystal structure of 3-(4-bromophenyl)-1-(4-nitrophenyl)triazene, 3-(2-flúorophenyl)-1-(4-nitrophenyl)triazene and 1-3-bis(4-azophenyl)triazene, shows that the stereochemistry about the N=N double bond in the diazoamine moiety is trans. Intermolecular interactions were observed in solid state. Treatment of palladium chloride and trans-[Pd(Cl)2(PPh3)2] with two equivalents of 1,3-disubstituted triazenes (RN=N-NHR), derived from 1-3-diariltriazenes, 3-(4-bromophenyl)-1-(4-nitrophenyl)triazenido, 3-(4-clorophenyl)-1-(4-nitrophenyl)triazenido, 3-(2-fluorophenyl)-1-(4-nitrophenyl)triazenido, 1,3-bis(pazophenyl) triazenido and pyridine, except for the reaction with trans-[Pd(Cl)2(PPh3)2], form complexes as deep red crystalline solids which form small crystal block. The palladium complexes exhibit square-plane coordination spheres with trans-1-3-diariltriazenes. A positional disorder effect was observed in (1). The unit cell of complex (2) is formed with two structure isomers. Complex (3) has intermolecular and intramolecular interactions via non-classic hidrogen bonds. The reaction between cis-[Pt(Cl)2(DMSO)2] and two equivalents of 1,3-disubstituted triazenes (RN=N-NHR), derived from 1-3-diariltriazenes, 3-(4-bromophenyl)-1-(4-nitrophenyl)triazenido, 3-(4-clorophenyl)-1-(4-nitrophenyl)triazenido, 3-(4-fluorophenyl)-1-(4-nitrophenyl)triazenido, 3-(2-fluorophenyl)-1-(4-nitrophenyl) triazenido and pyridine, all form complexes. The platinum complexes yield deep red crystalline solids which form small prismatic crystal. The complexes exhibit squareplane coordination with cis and trans 1-3-diariltriazenes. Complex (5) has intramolecular interactions via non-classic hidrogen bonds. The complexes (6), (7) e (8) have intermolecular and intramolecular interactions via non-classic hidrogen bonds. Two more complexes, one with nickel((II), and the other with mercury(II) were caracterized by X-ray crystallography, from red crystals of [NiII(Py)2(PhN2C6H4NNNC6H4R)2] (9) (Py = pyridine; R = 4-azophenyl) and {[HgII(Py)2(PhN2C6H4NNNC6H4R)2]2}n (10) (Py = pyridine; R = NO2). In the (9) we observed the first chelate coordination form of 1-3-bis(4-diazophenyl)triazene. Two triazenido ligands plus two molecules of pyridine are in a cis geometry in the coordination sphere. In (10) tectons {[HgII(Py)2(PhN2C6H4NNNC6H4R)2]2}n are linked in pairs as centrosymmetric dimers through reciprocal metal-2-arene p-interactions. The dimeric units are assembled by translation in the plane ac to unidimensional chains linked through non classical C−H×××O hydrogen bonds.