Layered Simple Hydroxides Functionalized by Fluorene‐Phosphonic Acids: Synthesis, Interface Theoretical Insights, and Magnetoelectric Effect

Abstract

International audienceCopper- and cobalt-based layered simple hydroxides (LSH) are successfully functionalized by a series of fluorene mono- and diphosphonic acids, using anionic exchange reactions and a preintercalation strategy. The lateral functionalization of the fluorene moieties has only little impact on the overall structure of the obtained layered hybrid materials but it influences the organization of the molecules within the interlamellar spacing. For bulky fluorene (9,9-dioctyl derivative), luminescence is preserved when inserted into copper and cobalt hydroxydes, whereas it is completely quenched for the other fluorenes. Detailed characterization of the internal structure and chemical bonding properties for copper- and cobalt-based hybrids is performed via ancillary experimental techniques. For the copper-based LSH class, for which more elusive findings are found, first-principles molecular dynamics simulations unravel the fundamental stabilizing role of the H-bonding network promoted within the local environments of the fluorene mono- and diphosphonic acids. The cobalt series of compounds constitute a new class of hybrid magnets, with ordering temperatures ranging from 11.8 to 17.8 K and show a clear magnetoelectric effect. This effect appears above a threshold magnetic field, which is null below the magnetic ordering temperature, and it persists in the paramagnetic regime till about 110 K

Designing of a Magnetodielectric System in Hybrid Organic–Inorganic Framework, a Perovskite Layered Phosphonate MnO3PC6H4‐m‐Br⋅H2O

“…Then, the hydrolysis of phosphonate to phosphonic acid can be achieved in acidic condition . Note that we placed the bromine atom in meta position respective to the phosphonic acid on the benzene ring because we have previously observed that the use of rigid organic precursors that feature a low symmetry contributed to the formation of non‐centrosymetric hybrid materials . To this goal, we used an excess of 1,3 dibromobenzene as substrate to favor the monophosphonation to produce compound 1 ( Scheme ).…”

“…Structures of MnPO 3 C 6 H 5 ⋅H 2 O and MnPO 3 C 6 H 4 ‐ m ‐Br⋅H 2 O: a) perovskite‐like MnPO 3 H 2 O layer containing PO 3 C tetrahedra, b) view of the MnPO 3 C 6 H 5 ⋅H 2 O structure along showing the b ≈ 14 Å periodicity after ref. , and c) view of the MnPO 3 C 6 H 4 ‐ m ‐Br⋅H 2 O structure along showing the c ≈ 31 Å periodicity.…”

“…Recently, layered cobalt hydroxide phosphonates have been reported to exhibit a MD effect. Yet the fact is that this system exhibits MD coupling from short‐range magnetic correlation in paramagnetic region …”

M(H2O)(PO3C10H6OH)·(H2O)0.5 (M = Co, Mn, Zn, Cu): a new series of layered metallophosphonate compounds obtained from 6-hydroxy-2-naphthylphosphonic acid

“…34,35 In a few cases, magneto-electric coupling was observed. [36][37][38] Since the properties of hybrid materials are influenced by the functionalization of organic precursors and after considering the incorporation of carboxylic acids 9 or halogen atoms into organic precursors 38,39 in addition to one or several phosphonic acid functions, 40 we investigate herein the conception of metal-phosphonate hybrids featuring phenol functions. Actually, only a few metal-phosphonate materials possessing phenol functions were previously reported in the literature.…”

Transparent Magnetoelectric Materials for Advanced Invisible Electronic Applications

“…[1,2] Single-phase ME materials [3][4][5] are sparse in nature and have limited applications, since they show weak ME response at very low operating temperatures. [9,10] These ME heterostructures [11] enable the conversion between magnetic and electrical energies through mechanical coupling between magnetostrictive and piezoelectric phases, [12] allowing a large number of applications including magnetic sensors, actuators, switches, energy harvesters, inductors, and data storage devices for smart electronic applications. [9,10] These ME heterostructures [11] enable the conversion between magnetic and electrical energies through mechanical coupling between magnetostrictive and piezoelectric phases, [12] allowing a large number of applications including magnetic sensors, actuators, switches, energy harvesters, inductors, and data storage devices for smart electronic applications.…”