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[N(CH 3 ) 4 ] 2 [Mn(H 2 O)] 3 [Mo(CN) 7 ] 2 ⋅2 H 2 O: A New High T c Cyano‐Bridged Ferrimagnet Based on the [Mo III (CN) 7 ] 4− Building Block and Induced by Counterion Exchange
Author(s) -
Larionova Joulia,
Clérac Rodolphe,
Donnadieu Bruno,
Guérin Christian
Publication year - 2002
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/1521-3765(20020617)8:12<2712::aid-chem2712>3.0.co;2-i
Subject(s) - ferrimagnetism , tetramethylammonium , crystallography , monoclinic crystal system , aqueous solution , chemistry , magnetization , molecule , crystallite , stereochemistry , materials science , crystal structure , ion , magnetic field , physics , organic chemistry , quantum mechanics
The title compound was synthesized by slow diffusion of aqueous solutions containing K 4 [Mo(CN) 7 ] ⋅ 2 H 2 O, [Mn(H 2 O) 6 ](NO 3 ) 2 , and [N(CH 3 ) 4 ]Cl. The compound crystallized in monoclinic space group C 2/ c, a =25.8546(14), b =12.3906(7), c =13.5382(7) Å, β =116.4170(10)°, Z =4, R =0.0353, wR2= 0.0456. The Mo III site is surrounded by six ‐C‐N‐Mn linkages and one terminal cyano group in a distorted capped‐prism fashion. There are two pentahedral Mn II sites in the structure, both with four ‐N‐C‐Mo linkages and one water molecule. The anisotropic three‐dimensional structure consists of connected corrugated gridlike sheet layers parallel to the bc plane. Tetramethylammonium counterions ([N(CH 3 ) 4 ] + ) located between these layers seem to induce their distortion. The three‐dimensional organization may also be viewed as interconnected octagonal channels propagated along the c axis. The void space of these channels is occupied by coordinated and crystallized water molecules. Temperature and field dependence of the magnetization in both the dc and ac modes have been measured on polycrystalline sample. These investigations have revealed that the compound ordered ferrimagnetically at T c =86 K, with a small hysteresis effect. These findings have been compared to those reported previously for three‐ and two‐dimensional materials of the same family.