Solvothermal Synthesis of the Canted Antiferromagnet {K2[CoO3PCH2N(CH2CO2)2]}6⋅x H2O

Abstract

A rare example of a molecular species prepared by solvothermal synthesis is the macrocyclic cobalt phosphonate/carboxylate 1, whose structure is shown schematically. At low temperatures this compound displays spontaneous magnetization due to canted antiferromagnetic ordering, which is very unusual for a discrete molecular material.

Solvothermal syntheses, characterizations and properties of two new NiII-PMIDA phosphonates

“…Phosphonic acid, N-(phosphonomethyl)iminodiacetic acid (H 4 PMIDA) with two additional carboxylic groups and one amine group, has been shown to be appropriate chelating ligand in a less acidic solution [8][9][10][11]. A number of the metal phosphonates containing the ligand H 4 PMIDA from zerodimensional to three-dimensional structures have been obtained [7][8][9][10][11][12][13][14][15][16][17].…”

“…A majority of the aforementioned materials were isolated from hydrothermal and conventional solution reaction, only a few of them prepared by solvothermal method during the synthesis process [17]. Herein we report the solvothermal synthesis, crystal structure and characterization of two new metal phosphonates:…”

Honeycomb-like layered cobalt(II) phosphonate with [O2CCH(OH)PO3]3− as ligand: Hydrothermal synthesis, crystal structure, and magnetic properties

“…Upon cooling v m T first gradually decreases to a minimum value of 1.33 cm 3 K mol À1 at 7 K, then abruptly increases to a sharp maximum value of 1.78 cm 3 K mol À1 at 4 K, and finally decreases more rapidly on further cooling. The abrupt increase in v m T value below 7 K is characteristic of a weak ferromagnet, in which a predominantly antiferromagnetic phase possesses a small spontaneous magnetization due to the spin canting [19,20]. Further support for this comes from the v m T vs. T curves at different fields that show a pronounced field dependence of the low-temperature phase, i.e.…”

“…A quantitative measure of the frequency shift of v 00 m is obtained from / = DT p /[T p D(log f)] = 0.04, which is comparable to a spin-glass rather than a superparamagnet (/ > 0.1) [23,24]. It should be noted that weak ferromagnetic ordering has been found in several metal phosphonates [4,5,19,25]. However, compound 1 shows the coexistence of spin-glass-like behavior, which is quite rare in metal phosphonate chemistry.…”

Synthesis and magnetic properties of a new Cr(II) ammonium-ethyl-phosphonate: Cr1.5[H3N(CH2)2PO3](SO4)·2H2O

“…Metal(II) phosphonates M II ½RPO 3 ðH 2 OÞ; where M is a divalent first series transition metal ion and R is an organic group, have provided interesting examples of magnetic solids [1,2]. They crystallize often in a lamellar structure, with alternating organic and inorganic layers along one direction of the unit-cell [3].…”