14121-58-5Relevant academic research and scientific papers
Cobalt(II) and copper(II) assembling through a functionalized oxamate-type ligand
Oliveira,Kalinke,Mascarenhas,Castro,Martins,Sabino,Stumpf,Ferrando,Julve,Lloret,Cangussu
, p. 105 - 114 (2014)
Two new metal complexes of formula {[Co(Hpcpa)(H2O) 3]n·3/2nH2O} (1) and [Cu 2(MeHpcpa)4(MeOH)2]·H 2O·3.68 MeOH (2) [H3pcpa = N-(4-carboxyphenyl) oxamic acid and MeH2pcpa = methyl ester derivative of H 3pcpa] have been synthesized and their structures determined by X-ray diffraction. 1 is a neutral zigzag chain of cobalt(II) ions bridged by Hpcpa2- ligands exhibiting the bidentate/monodentate coordination mode. Each cobalt(II) ion is six-coordinate with three mer positioned water molecules, two oxamate-oxygens from a Hpcpa2- ligand and a carboxylate-oxygen from another Hpcpa2- group building a somewhat distorted octahedral surrounding. The intrachain cobalt-cobalt separation is 11.326(2) A?. The structure of 2 consists of discrete syn-syn tetracarboxylate-bridged dicopper(II) units of the paddle wheel-type, the oxamate fragment of the MeHpcpa ligand being not involved in the coordination. Each copper(II) ion is five-coordinate in a distorted square pyramidal environment with four carboxylate-oxygens in the basal plane and a methanol molecule in the apical position. The intradimer copper-copper separation is 2.5974(11) A?. The magnetic properties of 1 and 2 have been investigated in the temperature range 1.9-300 K. The magnetic behavior of 1 corresponds to that of a magnetically isolated high-spin cobalt(II) ion with an important orbital contribution. The analysis of its magnetic data through the Hamiltonian, H = -αλLCo · SCo + Δ[L ZCo2 - 2/3] + βH(-αLCo + g eSCo) leads to the following set of best-fit parameters: α = 1.28(1), λ = -160(5) cm-1 and |Δ| = 400(20) cm-1. The magnetic properties of 2 show the occurrence of a strong antiferromagnetic interaction between the two local spin doublets which lead to a ground singlet spin state [J = -315(2) cm-1, the Hamiltonian being defined as H = -JSA·SB]. This value is in the upper range of those previously reported for the large family of tetracarboxylate- bridged dicopper(II) complexes, the exchange pathway being provided by the four carboxylate bridges in the syn-syn conformation mode.
New metal-organic systems with a functionalized oxamate-type ligand and MnII, FeII, CuII and ZnII
Maciel, Jhonny W.,Kalinke, Lucas H.G.,Valdo, Ana K.,Martins, Felipe T.,Rabelo, Renato,Moliner, Nicolás,Cano, Joan,Julve, Miguel,Lloret, Francesc,Cangussu, Danielle
, p. 2413 - 2429 (2020/01/03)
Four new complexes of formula [Fe(H2pcpa)2(H2O)2] (1), {[Mn(Hpcpa)(H2O)3]?1/2H2O}n (2), {[Zn(Hpcpa)(H2O)3]?1/2H2O}n (3) and
Synthesis, structural and biological studies of some oxamic acids and their CoII, NiIIand CuII metal complexes
Kumar, Devendra,Bhadauria, Anupama,Sharma
experimental part, p. 427 - 430 (2012/03/12)
Six new metal complexes of CoII, NlII and Cu II with N-(4-methoxyphenyl)oxamic acid and N-(4-carboxyphenyl)oxamic acid have been synthesized and characterized by elemental analyses, IR, 1H NMR and electronic spe
