Charge transfer adducts of binuclear rare earth 3, 5-dinitrobenzoates with N, N-dimethylaniline and toluene. (29th March 2015)

• Record Type: Journal Article
• Authors: Koroteev, Pavel S.; Ilyukhin, Andrey B.; Efimov, Nikolay N.; Minin, Vadim V.; Tyurin, Aleksandr V.; Dobrokhotova, Zhanna V.; Novotortsev, Vladimir M.
• Is Part Of: Polyhedron. Volume 89(2015)
• Page Start: 238
• Page End: 249
• Publication Date: 2015-03-29
• Subjects: Charge transfer complex -- Lanthanide 3, 5-dinitrobenzoate -- N, N-Dimethylaniline -- Supramolecular structure -- Magnetism; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2014.12.048
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: Binuclear 3, 5-dinitrobenzoates of lanthanides form stable charge transfer adducts with N, N -dimethylaniline (DMA), [Ln2 (O2 CC6 H3 (NO2 )2 )6 (DMSO)4 ]·3(Me2 N)C6 H5 (Ln = Eu (1 ), Gd (2 ), Tb (3 ), Dy (4 ), Y (5 )), and toluene, [Ln2 (O2 CC6 H3 (NO2 )2 )6 (DMSO)4 ]·(2 + n )MePh⋅(1 − n )DMSO (Ln = Eu (6 ), Gd (7 ), Tb (8 ), Dy (9 ), Y (10 ); 0 ⩽ n ⩽ 1). In the case of the DMA compounds, the charge transfer is strong enough to add a paramagnetic contribution to the compounds and to determine their 3D-supramolecular structures. Compounds of series1 –5 were studied by several physico-chemical methods in comparison with compounds of series6 –10 . Abstract: Crystallization of the products of an exchange between LnCl3 ·6H2 O and potassium 3, 5-dinitrobenzoate from N, N -dimethylaniline (DMA) in the presence of DMSO afforded the isostructural complexes [Ln2 (O2 CC6 H3 (NO2 )2 )6 (DMSO)4 ]·3(Me2 N)C6 H5 (where Ln = Eu (1 and its polymorphic modification1a ), Gd (2 ), Tb (3 ), Dy (4 ) and Y (5 )). In addition, formation of the metastable compounds [Tb2 (O2 CC6 H3 (NO2 )2 )6 (DMSO)4 ]·5(Me2 N)C6 H5 (3a ) and [Ln2 (O2 CC6 H3 (NO2 )2 )6 (DMSO)4 ]·4(Me2 N)C6 H5 (Ln = Eu (1b ), Tb (3b ), Dy (4a ), Y (5a )) was found. Due to charge transfer (CT), the stacking interactions between DMA molecules and 3, 5-dinitrobenzoate moieties occur, which determine the supramolecular structure of compounds1 –5 . The CT also determines the weak paramagnetism of the Y compound, but its effect on the overall magnetism of the compounds is insignificant. The structure and physicochemical properties of compounds1 –5 are considered in comparison with those of the newly synthesized complexes [Eu2 (O2 CC6 H3 (NO2 )2 )6 (DMSO)4 ]·2.2MePh⋅0.8DMSO (6 ), [Ln2 (O2 CC6 H3 (NO2 )2 )6 (DMSO)4 ]·3MePh (Ln = Gd (7 ), Tb (8 )), [Dy2 (O2 CC6 H3 (NO2 )2 )6 (DMSO)4 ]·2MePh·DMSO (9 ), and [Y2 (O2 CC6 H3 (NO2 )2 )6 (DMSO)4 ]·2.52MePh·0.48DMSO (10 ), in which CT is minor. For compound2, a correlation between the heat capacity and magnetic behavior is found. Gadolinium complexes2 and7 are found to have weak ferromagnetic interactions between the Gd 3+ ions. Complex9 displays the properties of a single molecule magnet. For compound2, standard thermodynamic functions were calculated.