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Synthesis, spectroscopy and magnetic properties of transition-metal complexes with aminophosphonate derivatives of pyridine

Żurowska B., Boduszek B.

Materials Science Poland

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2011

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Vol. 29, No. 2

105--111

EN

The compounds of general formula [ML2](ClO4)2 [M = Cu(II), Ni(II), Co(II)]; L = diethyl 3-pyridylmethyl[N-(butyl)amino]phosphonate (3-pmape) or diethyl 4-pyridylmethyl[N-(butyl)amino]phosphonate (4-pmape) were prepared. The new complexes were identified and characterized by elemental analysis, infrared, electronic spectral studies and magnetic measurements. The complexes are sixcoordinate. Metal ions are octahedrally surrounded by two pyridine and two amine nitrogens, and two oxygens of the phosphoryl groups. The results of the magnetic studies suggest polymeric chain structure of the above complexes and indicate weak antiferromagnetic interaction between the magnetic centers. The magnetic behavior of Co(II) complexes is characteristic for cobalt(II) system with an important orbital contribution via spin-orbit coupling.

2

Crystal structure and spectroscopic properties of [Zn(2-qmpe)Cl2] containing diethyl (quinolin-2-ylmethyl)phosphonate ligand (2-qmpe)

Żurowska B., Białońska A., Kotyński A., Ochocki J.

Materials Science Poland

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2010

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Vol. 28, No. 2

573--581

EN

The crystal structure of [Zn(2-qmpe)Cl2] (2-qmpe, diethyl (quinolin-2-ylmethyl) phosphonate) ligand) was determined by X-ray-diffraction. The compound was also characterized by IR, far-IR, 1H and 31P NMR spectroscopy. In the molecule, 2-qmpe acts as a bidentate N,O-chelate ligand. Tetrahedral ZnNOCl2 environment of Zn(II) atom is slightly distorted. The structure is stabilized by intermolecular H bond and n---n interactions. The spectral features are in agreement with the structural data.

3

Coordination properties of diethyl (pyridyn-2-ylmethyl)phoshate ligand with chloride transition metal salts

Żurowska B., Kalinowska-Lis U., Ochocki J.

Materials Science Poland

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2010

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Vol. 28, No. 3

749--755

EN

A new series of chloride transition metal complexes containing a diethyl (pyridyn-2-ylmethyl) phosphate (2-pmOpe) ligand, of the general formula [M(2-pmOpe)2Cl2] (M = Cu, Ni, Mn) and [M(2-pmOpe)Cl2] (M = Co, Zn), were synthesized and studied. The stoichiometry and stereochemistry of the compounds were confirmed by elemental analysis, spectroscopic and magnetic studies. The ligand containing two donor atoms, heterocyclic pyridyl nitrogen and phosphoryl oxygen atoms, binds in a didentate chelate manner in all complexes. The octahedral (Cu, Ni, Mn) and tetrahedral (Co, Zn) coordination sphere complete chloride ions included in coordination. The magnetic behaviour (for paramagnetic centres) and spectroscopic analyses of the complexes indicate a mononuclear structure and suggest existence of a very weak exchange coupling between the metal centres in the crystal lattice.

4

Structure and characterization of copper(II) perchlorate with diethyl(pyridin-2-ylmethyl) phosphonate (2-pmpe) ligand: [Cu(2-pmpe)2(ClO4)2]

Żurowska B., Białońska A., Ochocki J.

Materials Science Poland

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2009

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Vol. 27, No. 4/1

987--998

EN

Copper(II) mononuclear compound [Cu(2-pmpe)2(ClO4)2] (2-pmpe = diethyl(pyridin-2-ylmethyl) phosphonate was synthesized and studied. Examination of the crystal structure by the X-ray diffraction method revealed two crystallographically unrelated molecules, [Cu(1)(2-pmpe)2(ClO4)2] (1) and [Cu(2)(2-pmpe)2(ClO4)2] (2) in an asymmetric part of the unit cell. The geometry about the Cu(1) and Cu(2) chromophores shows elongated octahedra, resulting from the didentate N,O-bonded two chelate 2-pmpe ligands and two coordinated perchlorate ions around the Cu(II) cations (CuN2O4 chromophore). Similarly to 1, molecules 2 are linked to each other by weak C-HoooO hydrogen bonds and ?ooo? stacking interactions. Additionally, both 1 and 2 molecules are linked to each other through weak C-HoooO hydrogen bonds and C-Hooo? contacts, resulting in a 3D polymeric network arrangement. Magnetic data indicate a very weak intermolecular exchange interaction between copper(II) ions (zJ´ = -0.20 cm-1) transmitted through non-covalent interactions in the crystal lattice. The spectral properties are in accordance with the structural and magnetic data.

5

Coordination properties of the diethyl (pyridin-3-ylmethyl)phosphonate ligand (3-pmpe) with nitrate transition metal salts

Żurowska B., Kotyński A., Ochocki J.

Materials Science Poland

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2009

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Vol. 27, No. 4/1

999--1007

EN

A new series of nitrate transition metal complexes containing diethyl(pyridin-3-ylmethyl)phosphonate (3-pmpe) as a ligand, having a general formula [M(3-pmpe)2(H2O)2](NO3)2 (M = Cu, Co and Ni) and [Zn(3-pmpe)2](NO3)2 were prepared. The complexes were identified and characterized by the elemental analysis, spectroscopic and magnetic studies. Ligands containing two donor atoms, heterocyclic nitrogen and phosphoryl oxygen atoms bind in a bidentate bridging manner via the pyridine nitrogen and the phosphoryl oxygen atoms. The magnetic behaviour in the temperature range 1.8-300 K) of the Cu(II), Ni(II), Co(II) complexes as well as their spectroscopic properties suggest polymeric structure of all complexes and the existence of a weak antiferromagnetic exchange coupling between paramagnetic centres inside the dibridged linear chains [M(3-pmpe)2M]n.

6

Korelacje magnetyczno-strukturalne dla układów molekularnych Cu-pikolinian oraz Cu-chinaldynian

Żurowska B.

Wiadomości Chemiczne

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2008

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[Z] 62, 1-2

9-48

EN

This article concerns information on a synthesis, and structural and magnetic characterization of copper(II) compounds based on two classes of carboxylate ligands containing heterocyclic nitrogen atom of pyridine and quinoline i.e. pyridylo-2-carboxylate (2-picolinate, 2-pic) and quinolilo-2-carboxylate (2-chinaldynate, 2-qic), (Fig. 1, Tab. 1). Such compounds are products of a direct reaction of picolinate or chinaldynate acids with copper(II) salts [19, 37, 45, 48, 50, 51] and the hydrolytic [20, 52] and non hydrolytic [53] decomposition of ligands. Picolinate ion forms compounds of the general formula Cu(2-pic)2ź2H2O (1) or [Cu(2-pic)2Br2][(2-picH)2] (2). The compound of the formula Cu(pyridylo-2-carboxylate)2 exists in three polymorphic forms: monomeric (Cu(N2O2) chromophore) (3), and two (4 and 5) polymeric (1D) (Cu(N2O4) chromophore). With halide ions isostructural polymeric (2D) compounds of the formula Cu(2-pic)X, X= Cl (6) or Br (10) are formed (Cu(N2O2X) chromophore). However, with chinaldynate ion exist compounds of the stoichiometries: two isomeric forms of Cu(2-qic)2źH2O (7 and 8), which involve the same CuN2O3 chromophore (distortion isomers), and Cu(2-qic)X, X = Cl (9) and Br (11) compounds. The chloride and bromide (9 and 11) polymeric (2D) Cu(2-qic)X compounds, which crystal structure consists of two different chromophore Cu(N2O2X) and Cu(O2X2) are isostructural. Crystal structure of these copper-picolinate and copper-quinaldinate systems indicate, that carboxylate group in both ligands offers a variety of coordination modes leading to the formation of mononuclear and polynuclear compounds. The monomeric form of Cu(2-pic)2 (3) is an example of a square-planar copper(II) compound in which structure is achieved by important ?-? stacking intermolecular interaction. This interaction leads to antiferromagnetic coupling (J = -0.76 cm-1) [129]. The polymeric compounds of the formula Cu(2-pic)2 (4 and 5) are an example of an out-of-plane double carboxylato-bridged copper(II) compound resulting in the formation of an infinite chain. The magnetic properties revealed a weak intrachain antiferromagnetic coupling in both compounds (J = -0.73 and -1.04 cm-1 for 4 [48] and 5 [49], respectively). The structures of Cu(2-pic)X (6 and 10) and Cu(2-qic)X (9 and 11) compounds are based on syn-anti carboxylate bridge and additionally on halido-bridge. The carboxylate bridges transmit a weak ferromagnetic exchange (J < 0.5 cm-1) in both compounds [46, 47, 50]. For Cu(2-pic)X observed ferromagnetic coupling through dichloro-bridge (J = 15 cm-1) [46] is stronger than that through dibromo-bridge in bromide analog (J = 8.31 cm-1) [50]. For Cu(2-qic)X observed strong antiferromagnetic coupling through the single chloro-bridge (J = -57 cm-1) [47] is much weaker than that transmitted by the single bromo-bridge (J = -102.5 cm-1) [50]. The magnitude of the magnetic coupling through the non-covalent interactions (hydrogen bonds and ?-? stacking) is also discussed on the basis of the structural data [48, 49, 129, 130]. The magnitude of the exchange interactions between copper(II) ions are discussed on the basis of the molecular and crystal structures, in terms of bond properties and known theory of exchange [62-65, 100-104]. Keywords: copper(II), carboxylate ligands, halide ligands, structure, magnetism

7

Magnetic Interactions in Cu(pyridine-2-carboxylate)2

Żurowska B., Mroziński J., Ciunik Z.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 3

403-410

EN

The magnetic properties of the compound of the formula Cu(2-pca)2, (2-pca = 2-picolinate ion) were studied in the light of its known X-ray structure. The crystal structure consists of a copper atom lying in the centre of symmetry, trans square-planar coordinated via two pyridine nitrogens and the carboxylate oxygen atoms of the two picolinate anions. The crystal packing is due to short pi-pi stacking interactions between pyridine rings belonging to different molecules giving rise to a one-dimensional polymeric network arrangement. Additional CH-O hydrogen bonds form a three-dimensional polymeric network. The variable-temperature (1.8-300 K) magnetic susceptibility data of the complex were interpreted with the Bonner-Fisher expression with molecular field approximation, yielding J, zJ' and g values of -0.76, -0.47 cm-1, 2.09, respectively. The magnitude of the magnetic interaction through the pi-pi stacking interaction and hydrogen bond, and the nature of the exchange coupling is discussed on the basis of the structural data results.

8

Coordination properties of the diethyl 2-quinolilmethylphosphonate ligand with chloride and nitrate transition-metal salts

Żurowska B., Mroziński J., Ochocki J.

Materials Science Poland

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2007

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Vol. 25, No. 4

1063--1074

EN

A new series of the chloride and nitrate transition metal complexes containing the ligand diethyl 2-quinolylmethylphosphonate (2-qmpe) of general formula M(2-qmpe)(NO3)2 (M = Cu, Co), [Zn(2-qmpe)(H2O)2NO3]NO3ź H2O, [Ni(2-qmpe)(H2O)2NO3]NO3, M(2-qmpe)2Cl2 (M = Cu, Ni, Co, Pd) and M(2-qmpe)Cl2 (M = Co, Zn) were prepared. The complexes were identified and characterized by elemental analysis, spectroscopic and magnetic studies. Ligand containing two donor atoms, heterocyclic nitrogen and phosphoryl oxygen atoms exhibits different coordination properties. It was shown that the ligand binds in a bidentate chelate manner via the quinoline nitrogen and the phosphoryl oxygen atoms (complexes with 1:1 metal to ligand molar ratio) and it can also acts as a monodentate ligand coordinated through the nitrogen in the Pd(II) or oxygen atom in the Cu(II) and Co(II) complexes (complexes with 1:2 metal to ligand molar ratio). The magnetic behaviour of the Cu(II), Ni(II) and Co(II) and spectroscopic investigation of Zn(II) complexes suggests mononuclear structure of all the complexes and the existence of a weak intermolecular exchange coupling between magnetic centres inside crystal lattice.

9

Isomeric forms of Cu(quinoline -2-carboxylate)2.H2O compound: Spectroscopic, and magnetic properties

Żurowska B., Mroziński J.

Materials Science Poland

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2005

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Vol. 23, No. 3

737--744

EN

Spectroscopic and magnetic data of the compound Cu(2-qic)2 .H2O (1), where 2-qic is quinoline-2-carboxylate in the light of the known X-ray structure were studied. The geometry of CuN2O3 chromophore shows a very distorted five-coordinate stereochemistry intermediate between tetragonal pyramid and trigonal bipyramid resulting from the didentate N,O-bonded two chelate ligands and one water molecule. The crystal structure is stabilized by extended hydrogen-bonding network. Magnetic data reflect the molecular character of the compound with very weak exchange interaction (zJ' = - 0.23 cm-1), transmitted through H-bonds. The physico-chemical properties of 1 are compared with a recently reported forms 2 and 3 of identical stoichiometries Cu(quinoline-2-carboxylate)2.H2O obtained in an unusual oxidative P-dealkylation reaction. The compound 1 was prepared directly from quinaldinic acid.