Preparation, structure, and magnetic properties of a dodecanuclear mixed‐valence manganese carboxylate

Content Provider	Semantic Scholar
Author	Lis, Tadeusz
Copyright Year	1980
Abstract	This new type of dodecanuclear crystalline complex was obtained by reaction of Mn 2÷ with MnO 4 in acetic and propionic acids. The reddish-black acetate complex has the formula [Mn12(CHaCOO)I6(H20)4OI2 ] .2CH 3COOH.4H20, established by chemical and singlecrystal X-ray diffraction methods. This complex is tetragonal, space group I~,, with a -- 17.319 (9), c = 12.388 (7)/t,, V = 3716 ,/k 3, Z = 2, M r = 2060.3, D c = 1.84, D,,, = 1.83 Mg m -a. The final R and R w were 0.045 and 0.034 for 1172 non-zero reflexions. The crystals are built up of [MnIE(CH3COO)16(H20)4012] molecules, waters of crystallization and disordered acetic acid molecules. In the dodecanuclear molecules, which have 4 ($4) crystallographic symmetry, the Mn atoms are linked by triply bridging oxo O atoms and by carboxylate bridges from acetate anions. The occurrence of a strong Jahn-Teller effect in Mn a+ ions differentiates the Mn 3+ and Mn 4+ ions. The interesting magnetic properties (the magnetic moment increases from 30-9 x 10 -24 J T -1 at 3-3 K to a maximum of 56.5 x 10 -24 J T -~ in the range 17-31 K and then decreases to 33.4 x 10 -24 J T -~ at 280K per Mn atom) may be interpreted in terms of the Mn-Mn distances and superexchange via bridge O atoms.
Starting Page	2042
Ending Page	2046
Page Count	5
File Format	PDF HTM / HTML
DOI	10.1107/S0567740880007893
Volume Number	36
Alternate Webpage(s)	http://journals.iucr.org/b/issues/1980/09/00/a19066/a19066.pdf
Alternate Webpage(s)	https://doi.org/10.1107/S0567740880007893
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article