Bis(tetraethylammonium) tetrabromocobaltate(II) and bis(tetrabutylammonium) tetrabromomanganate(II): structure and magnetic properties

Abstract

The crystal structures of tetrabromocobaltate(II) and tetrabromomanganate(II) salts of general formula [(C 2 H 5 ) 4 N] 2 [CoBr 4 ] (1) and [(C 4 H 9 ) 4 N] 2 [MnBr 4 ] (2) were determined. The manganese and cobalt cations are four-coordinated by bromide anions and they adopt a slightly distorted tetrahedral coordination. In the structure of both compounds there are neither hydrogen bonds nor any unusual short-range intermolecular interactions. Magnetic measurements of the powdered samples gave negative values of the Weiss constants equal to -4.9 and -1.1 K for (1) and (2), respectively, which suggest antiferromagnetic interactions to be transferred within the crystal lattice.

Enhanced stability and complex phase behaviour of organic–inorganic green-emitting ionic manganese halides

“…It is also worth noting that such crystal packing motifs are rather common in similar compounds and were observed also for the ammonium analogue, [N 4444 ] 2 [MnBr 4 ] 2 . 39,50 Each anion is surrounded by six phosphonium cations ([P 4444 ] + ) in the form of a distorted octahedron (Fig. S9 †).…”

“…These interactions are however 39 which features the shortest Mn-Mn distance of 8.95 Å, but shorter than those for the polymorph crystallizing in Pnna where an Mn-Mn distance of 10.43 Å is reported. 50 For compound 2, crystals could be grown via slow diffusion of diethyl ether as the anti-solvent in acetonitrile solution of 2 (Fig. S12 †).…”

“…In the period between that study and today, the research on Mn(II) emitters based on tetraalkylammonium cations led to several materials, which have also seen application in electrochemical luminescent devices. 36,39,[43][44][45][46][47][48][49][50][51][52] Nonetheless, these were always characterised by short organic chains with up to four carbon atoms.…”

Temperature‐Induced Reversible Phase Transition with Switchable Dielectric Response in a A2BX4‐Type Hybrid Compound: [TEAMA]2[CdBr4] (TEAMA=(CH3CH2)3NCH3)

“…Several simple compounds with the general formula [(CH 3 CH 2 ) 4 N] 2 MX 4 (M=Mn 2+ , Fe 2+ , Co 2+ , Cu 2+ , Zn 2+ , Cd 2+ , etc. ; X=Cl, Br or I) were reported [10–14] . The reorientation dynamics of the cation and tetrahedral anion ions usually cause the structural phase transition accompanied by switchable dielectric anomalies.…”

Interplay of thermochemistry and Structural Chemistry, the journal (volume 21, 2010) and the discipline

“…Styczeń et al [75] describe the syntheses, characterization, and crystal structures of manganese and cobalt tetrabromometallates(II), [(C 2 H 5 ) 4 4 ]. Magnetic measurements suggest weak antiferromagnetic intermolecular interactions between the divalent metal ions in the crystal lattice.…”