Ionic complex of fullerene C602− dianions with (MDABCO+)2·MnIITPP coordination assemblies: synthesis, crystal structure and magnetic properties

Abstract

The crystals of the ionic complex containing fullerene C 602− dianions and positively charged ( MDABCO +)2· Mn II TPP assemblies: {( MDABCO +)2·MnII TPP }·( C 602−)·( C 6 H 4 Cl 2)4·( CH 3 CN )2 (1) were obtained for the first time ( MDABCO +: the cation of N-methyldiazabicyclooctane; TPP: tetraphenylporphyrin). The C 602− dianions are isolated in the complex with the shortest center-to-center distance of 13.228 Å. The Mn II atoms are six-coordinated in the ( MDABCO +)2· Mn II TPP units. The length of the Mn-N(TPP) equatorial bonds of 2.093-2.098(1) Å corresponds to the high-spin state of the Mn II atoms (S = 5/2) which was confirmed by the magnetic measurements (µ eff = 5.61 µ B at 300 K). The Mn II atoms are located exactly in the porphyrin plane and this results in the radial expansion of the porphyrin core. The long (2.537(1)−2.545(1) Å) Mn - N ( MDABCO +) axial bonds indicate essential destabilization of the six-coordinated ( MDABCO +)2· Mn II TPP units due to the population of the d ( z 2) orbital in high-spin state. The contribution from the C 602− dianions was not found in magnetic measurements on the basis of the contribution from high-spin Mn II TPP and most probably they are diamagnetic in the 2-300 K range.