Tetranuclear [Mn2Co2], [Mn2Fe2], and [Mn2Mn2] Complexes with Defective Double‐Cubane Cores and Phenoxo and Oxo Bridges: Syntheses, Crystal Structures, and Electronic Properties12. Issue 22 (24th June 2014)

• Record Type: Journal Article
• Authors: Malpaharia, Pijush; Pramanik, Koushik; Costes, Jean‐Pierre; Tuchagues, Jean‐Pierre; Moulton, Brian; Zaworotko, Michael J.; Das, Babulal; Chandra, Swapan K.
• Is Part Of: European journal of inorganic chemistry. Issue 22(2014)
• Page Start: 3527
• Page End: 3535
• Publication Date: 2014-06-24
• Subjects: Heterometallic complexes -- Magnetic properties -- Manganese -- Cobalt -- Iron; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.201402191
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract: Three new tetranuclear complexes [Mn III 2 Co III 2 O2 (L)2 ][ClO4 ]2 (1 ), [Mn III 2 Fe III 2 O2 (L)2 ][ClO4 ]2 (2 ), and [Mn III 2 Mn III 2 O2 (L)2 ][Mn II (NCS)4 ] (3 ) have been synthesized through reactions of the mononuclear [Mn III L] precursor with the corresponding metal perchlorate under aerobic conditions [H3 L = tris(2‐salicylaldimine)amine, a condensation product between tris(2‐aminoethyl)amine and salicylaldehyde in a 1:3 molar ratio]. These compounds have been characterized by spectroscopic and analytical techniques including single‐crystal X‐ray structure analysis, electron paramagnetic resonance (EPR) spectroscopy, Mössbauer spectroscopy, and magnetic measurements. The structure of1 consists of oxo‐/phenoxo‐bridged Co III and Mn III centers in a defective double‐cubane topology. The molecules of2 and3 have similar structures with the Co III centers changed to Fe III centers in2 and to Mn III centers in3 . These isostructural complexes have been scrutinized with regard to changes in distortions (distances and angles) of the metal coordination spheres. Magnetic studies indicate that1, 2, and3 show predominant antiferromagnetic interactions. Changes in the electronic properties concomitant with changes in the distortions in1, 2, and3 are analyzed in terms of magnetostructural correlations. Abstract : The syntheses, crystal structures, and electronic properties of three tetranuclear [Mn2 Co2 ], [Mn2 Fe2 ], and [Mn2 Mn2 ] compounds are described. These complexes possess defective double‐cubane [Mn2 M2 O2 ] 8+ cores and are interesting examples that show how small structural changes in molecule‐based magnetic compounds can strongly affect the overall electronic properties.