New Zn(II) and Cd(II) coordination polymers based on bifunctional bis-m-aminobenzoylglyoxime
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2022-08-18 13:17
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RIJA, Andrei, BOUROSH, Pavlina, COROPCEANU, Eduard, URECHE, Dumitru, BULHAK, Ion. New Zn(II) and Cd(II) coordination polymers based on bifunctional bis-m-aminobenzoylglyoxime. In: The International Conference dedicated to the 55th anniversary from the foundation of the Institute of Chemistry of the Academy of Sciences of Moldova, 28-30 mai 2014, Chișinău. Chișinău, Republica Moldova: Institutul de Chimie al AȘM, 2014, p. 58.
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The International Conference dedicated to the 55th anniversary from the foundation of the Institute of Chemistry of the Academy of Sciences of Moldova 2014
Conferința "The International Conference dedicated to the 55th anniversary from the foundation of the Institute of Chemistry of the Academy of Sciences of Moldova"
Chișinău, Moldova, 28-30 mai 2014

New Zn(II) and Cd(II) coordination polymers based on bifunctional bis-m-aminobenzoylglyoxime


Pag. 58-58

Rija Andrei12, Bourosh Pavlina3, Coropceanu Eduard1, Ureche Dumitru2, Bulhak Ion1
 
1 Institute of Chemistry of the Academy of Sciences of Moldova,
2 Tiraspol State University,
3 Institute of Applied Physics, Academy of Sciences of Moldova
 
 
Disponibil în IBN: 21 ianuarie 2019


Rezumat

A new glyoximederived from dichloroglyoxime and m-aminobenzoic acid as well as new polymeric compounds of [Zn(DmabaH2)(H2O)(DMF)]n (I) and [Cd(DmabaH2)(H2O)2]n(II) with this ligand were synthesized and described by IR, RMN spectroscopies and X-ray crystallography. The versatility of this ligand is due to his peripherical functional group which is able to coordinate to metal through both oximic and carboxylic fragments.Bis-maminobenzoylglyoxime (DmabaH4) with its eight potential donor sites is a suitable scaffold to construct a stable metal-containing polymeric architecture. Zn(II) and Cd(II) are known to form coordination compounds with polymeric structure. Therefore,crystals suitable for X-ray study were obtained from M(CH3COO)2 – DmabaH2system in 1:1 molar ratio. In the IR spectrum of DmabaH4 the bands at ν(C=O)1693, ν(CC)arom+ν(C=N)1635, ν(NO)941 and δ(CH)691, 716, 753 cm-1are observed. The presence of these bands and absence of ν(C–Cl) band at 850 cm-1 of dichloroglyoxime confirm the condensation of m-aminobenzoic acid to dichloroglyoxime. Upon coordinationthe ν(C=O) band shifts to lower energy at 1656and 1654 for Zn(II) and Cd(II) complexes. In the 1H NMR spectraof these complexes the signals for –OH and –NH groups are upfield shifted with 0.79 and 0.44 ppm respectively comparative to free ligand being the only ones shifted so much. All signals in13C NMR spectra are not shifted more than 3ppm comparative to free ligand. Compound I crystallizes in the monoclinic space group P21/c, II – in the orthorhombic space group Pbcn. In I and II the symmetricstructural units [Zn(DmabaH2)(H2O)(DMF)] and [Cd(Cd(DmabaH2)(H2O)2)] form 2D coordination polymers. In these units Zn(II) and Cd(II) are hexacoordinatedwith a square bipyramidal environment. In I, each Zn(II) cationbinds twooxime N atoms and two O atoms (from two others bideprotonated DmbaH2residues)forming the equatorial plane of the coordination polyhedron.The axial positions are occupied by two O atoms ofone water and one DMF molecules. Cd(II) cation in II has the same environment as I except axial position where only water molecules are founded. The equatorial Me–N bond lengths are 2.227(2), 2.135(3) Å in I and 2.314(6), 2.387(6) Å in II and Me–O – 1.986(2), 2.023(2) Å in I and 2.232(5), 2.215(5) Å in II. The axial Me–O bond lengths are 2.145(2), 2.192(3) Å in I and 2.301(6), 2.307(5) Å in II. In these compounds DmabaH2 serves as both chelate and bridging ligand linking together three metal atoms (Fig.1). The oxime and carboxyl groups coordinated to the same atom form strong H-bonds between them with donor – acceptor distance 2.596 – 2.657 Å. The aromatic rings form π-π interactions with the distance between aromatic centers of 3.730 Å.