Polar metal phosphonate containing unusual μ4-OH bridged double chains showing canted antiferromagnetism with large coercivity

Abstract

The first examples of metal phosphonates based on an asymmetrical 2-(phosphonomethyl)benzoic acid (2-pmbH3) are reported, namely, Co2(μ4-OH)(2-pmb) (1) and Cu4(μ3-OH)2(2-pmb)2 (2). Both crystallize in polar space groups and show layered structures. Compound 1 contains unusual μ4-OH bridged double chains of {Co2(μ4-OH)O3}, inter-connected by the phosphonate groups. In 2, chair-like tetramers of Cu4(μ3-OH)O2 are linked by both carboxylate and phosphonate groups. Magnetic studies reveal that compound 1 experiences canted antiferromagnetic ordering below 31.0 K with a large coercivity of 4.3 Tesla at 2 K.

Spectrally-resolved third-harmonic generation and the fundamental role of O–H⋯Cl hydrogen bonding in Oh, Td-cobalt(ii) tetraphenylmethane-based coordination polymers

“…Noteworthily, this CP is a centrosymmetric analogue related to SHG-active phosphonate-ester non-centrosymmetric CPs. 11 As a result of its peculiar structure, apart from NLO studies, CP 2-Cl gave us the possibility to investigate unusual for most of the phosphonates [14][15][16][17][18][19][20][21][22][23] and phosphonate monoester [24][25][26][27][28] CPs structural aspects, important from the viewpoint of crystal engineering. It is the moderate strength of dialkylphosphonate binding via phosphoryl (PvO) donor coordination combined with the bulkiness of this functional group that induces monodentate axial binding of metal ions.…”

Dynamic Motion of Organic Ligands in Polar Layered Cobalt Phosphonates

“…A number of cobalt phosphonates have been reported to show an interesting magnetic behavior, such as ferrimagnetism, weak ferromagnetism, and metamagnetism . Polar cobalt compounds can offer unique opportunities for exploring new multifunctional materials, such as multiferroic materials combining polarity and magnetism . Bearing this in mind, we also studied the magnetic properties of compounds 1 – 4 .…”

“…[47,48] Polar cobalt compounds can offer unique opportunities for exploring new multifunctional materials, such as multiferroic materials combining polarity and magnetism. [49][50][51] Bearing this in mind, we also studied the magnetic properties of compounds 1-4.F igures 4a nd S17 in the Supporting Information show the temperature-dependentm agnetic susceptibilities measured under ad irect current (dc) field of 1kOe and at emperature range of 1.9-300 K. At room temperature,t he c m T products for compounds 1-4 are 3.08, 3.20, 3.38, and 3.31 cm 3 mol À1 K, respectively.T hese values are much larger than the spin-only value of 1.88 cm 3 mol À1 Kf or isolated Co II ions (S = 3/2 and g = 2.0), attributed to the orbital contributiono ft he octahedral cobalt(II) ion. Upon cooling, the c m T values decrease continuously and approach0 .10, 0.09, 0.13, and 0.10 cm 3 mol À1 Ka t1 .9 Kf or compounds 1-4,r espectively,a rising from antiferromagnetic (AF) interactionsa nd/or spin-orbitalc ouplings in the materials.…”

Syntheses, structures and properties of group 12 element (Zn, Cd, Hg) coordination polymers with a mixed-functional phosphonate-biphenyl-carboxylate linker

“…40 Cobalt and iron organophosphonates exhibit magnetic properties. [41][42][43][44][45][46][47][48] Organophosphonates can contain additional functional groups such as carboxylate, hydroxyl or amino in the organomoiety which presents a tunable functionality with a wide variety of structural motifs and properties. 49 The controlled growth of crystalline metalorganophosphonate complexes is not a straightforward procedure.…”