A pseudo-icosahedral cage {Gd₁₂} based on aminomethylphosphonate

Abstract

Reaction of (aminomethyl)phosphonic acid (ampH2) with a mixture of gadolinium and cobalt pivalates under solvothermal conditions, led to a pseudo-icosahedral cage {Gd12}, which shows a large magnetocaloric effect (MCE).

Synthesis, Crystal Structures, and Magnetic Properties of Lanthanide (III) Amino-Phosphonate Complexes

“…Three different amino-phosphonate binding modes are found in the compounds. Previous results from our group and others indicate that the alkyl groups attached to the aminophosphonic acid has a strong effect on the structures and properties of the lanthanide(III) phosphonates isolated [38,39]. The aminophosphonic acids, H 2 NRPO 3 H 2 (R = alkyl or aryl group), have been proved to be very useful ligands for the synthesis of metal phosphonates with new structure types in which the organic part plays a controllable spacer role and the two inorganic-PO 3 groups chelate with metal ions to form one-, two-, and three-dimensional structures [64,65].…”

“…Previous studies have shown that the phosphonate moiety is an efficient functional group for the construction of molecular cages [38,39]. Winpenny and co-workers reported results using t-butylphosphonic acid (H 2 3 ] + cation, the anion of the compound contains nine Ln(III) metal ions in a ring and a tenth Ln(III) metal ion at the center of the structure, the ten metal sites are almost co-planar.…”

“…Previous studies have shown that the phosphonate moiety is an efficient functional group for the construction of molecular cages [38,39]. Winpenny and co-workers reported results using t-butylphosphonic acid (H2O3P t Bu) reacted with lanthanide salts Ln(NO3)3·nH2O or lanthanide pivalates (Ln = Gd(III), Tb(III), Dy(III), Ho(III), and Er(III) [12,13,39]. Winpenny and coworkers have also synthesized a decanuclear 3d-4f phosphonate cage of [Co4Ln10(O2C t Bu)12(O3PC6H10NH2)8(PO4)2(O2CMe)2(O3PC6H10NH3)2] (Ln = Gd, Dy) [38].…”

“…Three of the six phosphonates lie below the plane of the {Ln10} disc and adopt the 4.221 binding mode, the remaining three phosphonates are above the plane of metal centers; two of them adopt the 3.111 binding mode, while the third adopts the 3.211 mode [52]. Another frequently used ligand to the polynuclear 4f molecular cages is α-amino acids [42][43][44][45], thus 1-amino-1-cyclohexyl phosphonic acid is supposedly a good ligand to synthesize 4f molecular cages ( Figure 2) [38,39]. …”

“…Much of recent work has so far focused on the exploration of metal phosphonate materials with new structural types, and a large number of metal phosphonates were prepared through designing and synthesizing phosphonic synthesizing phosphonic acids with different functional organic groups [7,[33][34][35][36][37]. More recently, a series of metal phosphonates, using phosphonic acids containing -NH2 sub functional group were also isolated under solvothermal condition [38,39].…”