The Structure of Mn(acac)3—Experimental Evidence of a Static Jahn–Teller Effect in the Gas Phase. Issue 49 (7th November 2017)

• Record Type: Journal Article
• Authors: Berger, Raphael J. F.; Girichev, Georgiy V.; Giricheva, Nina I.; Petrova, Angelika A.; Tverdova, Natalya V.
• Is Part Of: Angewandte Chemie international edition. Volume 56:Issue 49(2017)
• Page Start: 15751
• Page End: 15754
• Publication Date: 2017-11-07
• Subjects: electronic structure -- gas-phase studies -- high spin -- manganese(III); Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201708498
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The structure of free manganese(III) tris(acetylacetonate) [Mn(acac)3 ] was determined by mass‐spectrometrically controlled gas‐phase electron diffraction. The vapor of Mn(acac)3 at 125(5) °C is composed of a single conformer of Mn(acac)3 in C2 symmetry with the central structural motif of a tetragonal elongated MnO6 octahedron and 47(2) mol % of acetylacetone (Hacac) formed by partial thermal decomposition of Mn(acac)3 . Three types of Mn−O separations have been refined (rh1 =2.157(16), 1.946(5), and 1.932(5) Å. We have found no indication for a significant deviation of the ‐C−C−C−O−Mn−O‐ six‐membered rings from planarity, which is observed in the solid state. Abstract : Too symmetric to be true : An experimentally determined molecular structure of Mn(acac)3 displays a rare example of a static Jahn–Teller distortion in the gas phase. The one‐conformer composition in the gas phase is in contrast to the situation in the solid state, with its many different distorted structures from five different modifications.