Síntese e caracterização de polímeros de coordenação contendo o ácido 3-fenil-propiônico e ligantes derivados piridilas

Abstract

A new family of one-dimensional copper(II)-3-phenylpropionate coordination polymers was synthesized and structurally characterized by elemental analyses (C, H, N and S), thermogravimetry (TG) and differential thermal analysis (DTA), vibrational spectroscopy and X-ray diffraction (powder and single-crystal). Four novel coordination polymers were obtained and named as: [Cu2(O2CC8H9)4(4,4’-dps)]n (1), {[Cu(O2CC8H9)2(4,4’-dps)(H2O)].H2O}n (2), [Cu(O2CC8H9)2(µ-bpm)Na(NO3)]n (3) and [Cu6(O2CC8H9)9(OH)3(bpp)3]n (4) wherein O2CC8H9= 3-phenylpropionate anion, 4,4’-dps = di(4-pyridyl)sulfide, bpm = 2,2’-bipyrimidine and bpp= 1,3-bis(4-pyridyl)propane. Compound 1 belongs to a large group of copper (II) carboxylates containing the dinuclear [Cu2O8] unit, where the 4,4’-dps ligands connect the paddle-wheel [CuII2(µ-O2CC8H9)4] units leading to alternating copper(II) chains. When a dimethylformamide/water solution of 1 was left stand for longer than ten days, structural rearrangement of compound 1 is observed, giving rise to compound 2. The structure of 2 consists of uniform chains of trans-[CuII(O2CC8H9)2] units linked by the bis-monodentate 4,4’-dps ligand. Compound 3 consists of heterobimetallic chains where [NaI2CuII2(µ-O2CC8H9)4(NO3)2] units are doubly bridged by bis-bidentate bpm ligands. Compound 4 is also a chain compound whose structure is made up by tetranuclear [CuII4(µ3-OH)2(µ-O2CC8H9)4(O2CC8H9)2] units which are doubly bridged by bis-monodenate bpp ligands. Thus, this work deals with the synthesis and structural studies of four copper (II) coordination polymers built by 3-phenylpropionate-based SBUs (secondary building units) of copper (II) and rigid and flexible nitrogen donors ligands.