Rodrigue Lescouezec

Sorbonne University | UPMC · Institut Parisien de Chimie Moléculaire (IPCM)

A prelude to redox-based, ferromagnetic "metal-organic switches" is exemplified by a new trinuclear oxalamide cobalt triple mesocate that presents two redox states (ON and OFF) with dramatically different magnetic properties; the two terminal high-spin d(7) Co(II) ions (S = (3)/(2)) that are ferromagnetically coupled in the homovalent tricobalt(II)...

The heterometallic hexanuclear cyanide-bridged complex {[Mn(bpym)(H(2)O)](2)[Fe(HB(pz)(3))(CN)(3)](4)} (1), its C(15)N and D(2)O enriched forms {[Mn(bpym)(H(2)O)](2)[Fe(HB(pz)(3))(C(15)N)(3)](4)} (2) and {[Mn(bpym)(D(2)O)](2)[Fe(HB(pz)(3))(CN)(3)](4)} (3), and the hexanuclear derivative complex {[Mn(bpym)(H(2)O)](2)[Fe(B(pz)(4))(CN)(3)](4)}·4H(2)O...

Electrospray ionization (EI) deposition is proven efficient in obtaining monolayers of a polymetallic charge transfer complex onto gold surfaces. The molecule’s integrity is monitored by PM-IRRAS and XPS. This approach...

As the development of aluminum-ion batteries is still in its infancy, researchers are still dedicated to exploring suitable host materials and investigating their aluminum intercalation behaviours. Here, a series of...

A two-step thermo-induced spin-state switching was observed in a cyanide-bridged [Fe2Fe2] molecular square complex, {[Fe(pzTp)(CN)3]2[Fe(L)2]2}[Fe(pzTp)(CN)3]2·4CH3OH·2H2O [1·4MeOH·2H2O; pzTp = tetrakis(pyrazol-1-yl)borate and L = bis(1-ethylimidazol-2-yl)ketone (bik*)], which was characterized fully by single-crystal X-ray diffraction, (photo)magn...

A mixed-valence Fe(II)Fe(III) molecular system, {[Fe(pzTp)(CN)3]2[Fe(bik)2]2}·[Fe(pzTp)(CN)3]2·4MeOH (1·4MeOH) (bik = bis-(1-methylimidazolyl)-2-methanone, pzTp = tetrakis(pyrazolyl)borate), exhibits single-crystal-to-single-crystal (SC-SC) transformation while increasing the temperature and is converted into {[Fe(pzTp)(CN)3]2[Fe(bik)2]2}·[Fe(pzTp)...

The cyanidocobaltate of formula fac‐PPh4[CoIII(Me2Tp)(CN)3] ⋅ CH3CN (1) has been used as a metalloligand to prepare polynuclear magnetic complexes (Me2Tp=hydrotris(3,5‐dimethylpyrazol‐1‐yl)borate). The association of 1 with in situ prepared [FeII(bik)2(MeCN)2](OTf)2 (bik=bis(1‐methylimidazol‐2‐yl)ketone) leads to a molecular square of formula {[CoI...

FeCo Prussian blue analogues of general formula AxCoy[Fe(CN)6]z are responsive, non-stoichiometric materials whose magnetic and optical properties can be reversibly switched by light irradiation. However, elucidating the critical influence of the inserted alkali ion, A+, on the material's properties remains complicated due to their complex local st...

We describe herein the first examples of six-coordinate CoII single-ion magnets (SIMs) based on the β-diimine Mebik ligand [Mebik = bis(1-methylimidazol-2-yl)ketone]: two mononuclear [CoII(Rbik)2L2] complexes and one mixed-valence {CoIII2CoII}n chain of formulas [CoII(Mebik)(H2O)(dmso)(μ-NC)2CoIII2(μ-2,5-dpp)(CN)6]n·1.4nH2O (3) [L = NCS (1), NCSe (...

Responsive materials that can answer to chemical or physical external stimuli offer numerous prospects in material science. Here, we have elaborated a two-step synthetic approach that allows incorporating molecular cubic switches into a polymeric material. Firstly, a preformed half-capped, Cs +-templated {Fe 4 Co 4 } cyanido-polymetallic cubic unit...

The [FeII(C6F5Tp)2] spin‐crossover complex is an atypical molecular switch, which can be converted upon annealing between two archetypal spin‐crossover behaviours: from an extremely gradual spin‐crossover to a broad hysteretic spin‐transition (of ca. 65 K). The hysteresis shows an uncommon “rounded shape” that is reproducible upon cycling temperatu...

The [FeII(C6F5Tp)2] complex is converted through melting from a crystal phase showing a very gradual spin‐crossover to another one showing a broad hysteretic spin‐transition. The uncommon „rounded“ hysteresis occurs in a non‐cooperative SCO system. It is due to a symmetry‐breaking phase transition that is triggered when roughly ca. 50 % of the SCO...

Correction for 'Thermo- and electro-switchable Cs⊂{Fe4-Fe4} cubic cage: spin-transition and electrochromism' by Jana Glatz et al., Chem. Commun., 2020, DOI: 10.1039/d0cc04279j.

A cyanide-bridged [Fe2Co2] molecular square complex, {[Fe(Tp)(CN)3]2[Co(L)2]2}(BF4)2·2CH3CN·6H2O [1; Tp = hydrotris(pyrazol-1-yl)borate and L = bis(1-ethyl-1H-imidazol-2-yl)ketone], has been synthesized and characterized fully by single-crystal X-ray diffraction, (photo)magnetic measurements, optical reflectivity, and other physical measurements. 1...

A mixed valence Cs{Fe4-Fe4} cyanido-cube was synthesized and structurally characterized. The molecule, which is robust in solution, shows a remarkable electronic versatility. Electrochromic properties associated with nine different electronic states...

A key challenge in the design of magnetic molecular switches is to obtain bistability at room temperature. Here, we show that application of moderate pressure makes it possible to convert a paramagnetic FeIII2CoII2 square complex into a molecular switch exhibiting a full dia‐ to paramagnetic transition: FeIICoIII ⇔ FeIIICoII. Moreover, the complex...

A key challenge in the design of magnetic molecular switches is to obtain bistability at room temperature. Here, we show that a moderate pressure allows converting a paramagnetic Fe III 2 Co II 2 square complex into a molecular switch exhibiting a full dia‐ to para‐magnetic transition: Fe II Co III ⬄ Fe III Co II . Moreover, the complex follows a r...

A mixed‐valence {MnII3MnIIIFeII2FeIII2} cyanide‐bridged molecular cube hosting a caesium cation, Cs⊂{Mn4Fe4}, was synthesized and structurally characterized by X‐ray diffraction. Cyclic‐voltammetry measurements show that its electronic state can be switched between five different redox states, which results in a remarkable electrochromic effect. Ma...

Synthese ins Blaue: Der Cs⊂{Mn4Fe4}-Würfel, das erste lösliche molekulare Modell der MnFe-Analoga von Berliner Blau, wird mittels Röntgenbeugung, Cyclovoltammetrie, UV/Vis-Absorptionsspektroskopie und magnetischer Messungen untersucht. Nahe Raumtemperatur findet ein Wechsel des Spinzustands statt, der einem Metall-zu-Metall-Elektronentransfer zuges...

The local magnetic structure in the [FeIII(Tp)(CN)3]⁻ building block was investigated by combining paramagnetic Nuclear Magnetic Resonance (pNMR) spectroscopy and polarized neutron diffraction (PND) with first‐principle calculations. The use of the pNMR and PND experimental techniques revealed the extension of spin‐density from the metal to the lig...

Three novel mixed valence cyanide-bridged {Fe III2 Fe II2 } square complexes were obtained through the self-assembling of [Fe III (Tp)(CN) 3 ] ⁻ or [Fe III (Tp*)(CN) 3 ] ⁻ cyanido building blocks with the in situ formed [Fe II (bik) 2 (S) 2 ]complex (Tp = hydrotris (pyrazol-1-yl)borate, Tp* = hydrotris (3,5-dimethyl-pyrazol-1-yl)borate, bik = bis(1...

Efficient energy storage in the form of batteries contributes to building sustainable society. As advanced batteries need positive electrode materials capable of larger capacity, higher voltage, and lower cost, it is important to search for novel electrode materials. Among various inorganic/organic materials, cyanido-bridged coordination compounds...

Four sterically congested and highly electronically unsaturated bis(5-aryl-2-iminopyrrolyl) ML2 complexes of Fe(II) and Co(II), [M{κ²N,N-5-(2,6-R2-C6H3)-NC4H2-2-C(H)[dbnd]N(2,6-ⁱPr2-C6H3)}2] (M = Fe, R = H (1a); M = Fe, R = Me (1b); M = Co, R = H (2a); M = Co, R = Me (2b)), were synthesized by metathetic reaction of the in situ prepared sodium salt...

Two new iron(II) neutral complexes of bis(1-methylimidazol-2-yl)ketone (Mebik) with molecular formula [FeII(Mebik)2(NCS)2] (1) and [FeII(Mebik)2(NCSe)2] (2) have been synthesized and characterized by magnetic measurements, single-crystal X-ray diffraction, and solid state UV-vis spectroscopy. The temperature dependent magnetic susceptibility measur...

Using a scorpionate-based complex, [FeIII(Tp)(CN)3]-, as a bulding block, a new cyanide-based molecular material [{FeIII(Tp)(CN)3}2NiII(H2O)2]∙4H2O (1), which can be viewed as a lower dimensional model of Prussian blue analogues, was...

Cyanide coordination clusters have received attention for their electronic and magnetic properties. Here, we synthesized a new octametallic cyanide box encapsulating a Cs⁺. The cationic complex Cs⊂[FeIII4(Tp)4NiII4(NMe2Tp)4(μ-CN)12]⁺ was crystallized as a BF4⁻ salt and its structure reveals that the cesium ion interacts with the twelve cyanide edge...

We report a new cyanide-bridged Cs⊂{Fe4Co4} box, a soluble model of photomagnetic Prussian blue analogues (PBAs). The Cs+ ion has a high affinity for the box and can replace the K+ ion in the preformed K-cube. The exchange is kinetically impeded at room temperature but is accelerated by heating and using the 18-crown-6 ether. The inserted Cs+ confe...

We demonstrate that 113Cd NMR is a potent technique to monitor the local electronic and structural states of the Prussian blue electrode during Li+ intercalation, providing an atomic-scale insight into the reaction mechanism.

A nanoscopic {Fe60} coordination cage (approximately 3 nm) was prepared by the self assembly of a partially blocked tricyanidoferrate(iii) complex and tris(alkoxo)-based iron(iii) coordination motifs. This cage is a rare example of a mixed cyanido/alkoxo-bridged high nuclearity complex and it exemplifies the great potential of this new synthetic ro...

Straightforward access to a new cyanide-bridged {Fe4Co4} "molecular box" containing a potassium ion, namely K⊂{[FeII(Tp)(CN)3]4[CoIII(pzTp)]3[CoII(pzTp)]} (1) (with Tp and pzTp = tris- and tetrakis(pyrazolyl)borate, respectively), is provided, alongside its full characterisation. A detailed analysis of the molecular structure (X-ray diffraction, ma...

We have determined by polarized neutron diffraction (PND) the low-temperature molecular magnetic susceptibility tensor of the anisotropic low-spin complex PPh4 [Fe(III) (Tp)(CN)3 ]⋅H2 O. We found the existence of a pronounced molecular easy magnetization axis, almost parallel to the C3 pseudo-axis of the molecule, which also corresponds to a trigon...

The reaction of [FeIII(Tp)(CN)3]- with [CoII(vbik)2(S)2]2+ leads selectively to the crystallization of cyanide-bridged diamagnetic {FeIILSCoIIILS}2 squares at 5°C or paramagnetic {FeIIILSCoIIHS}2 ones at 35°C. The diamagnetic crystal phase can be converted to a paramagnetic one upon heating and it shows photomagnetic effect at low temperature.

Straightforward access to a new cyanide-bridged {Fe4Co4} “molecular box” containing a potassium ion, namely K⊂{[FeII(Tp)(CN)3]4[CoIII(pzTp)]3[CoII(pzTp)]} (1) (with Tp and pzTp = tris- and tetrakis(pyrazolyl)borate, respectively), is provided, alongside its full characterisation. A detailed analysis of the molecular structure (X-ray diffraction, ma...

a The aim of this paper is to demonstrate the possibility of expressing molecular magnetic phenomena on hybrid nano-particles. The advantage of such composite materials is their wonderful versatility, in terms of choice of molecular compounds to be grafted on, and in terms of possibilities for integration in devices. As a first example, we designed...

The self-assembly of [Mo(V)(CN)8](3-) and [Fe(II)(bik)2(S)2](2+) affords a cyanide-bridged {Mo(V)2Fe(II)2} rhombus molecule that shows photomagnetic effect under laser light irradiation at low temperature and exhibits thermo-induced spin crossover near ambient temperature.

With the aim of probing the spin density distribution in the open-shell cyanometallates Cs2K[M(CN)6] (M = Cr, Mn, Fe), K3[M(CN)6] (M = Mn, Fe), K4[M(CN)6] (M = Cr, Mn), and K4[V(CN)7] have been studied by solid-state (13)C and (15)N NMR spectroscopy. The signals appear in strongly shifted and broad ranges ((13)C, -2100 to -8900 ppm; (15)N, -1900 to...

As an original synthetic route to molecular magnetic 12 materials, we have reacted partially-blocked cyanometalates with preformed 13 coordination cluster. The association of the fac-[Fe(Tp)(CN) 3 ] − 14 assembling metalloligand with the [Cu 3 (OH)(pz) 3 ] 2+ trigonal cluster has 15 afforded a novel coordination network where the trimetallic copper...

Molecular (photo)switch: A WCo photomagnetic discrete complex can be prepared through the self-assembly of preformed building blocks. [Co(bik)3][{W(CN)8}3{Co(bik)2} 3]×2 H2O×13 CH3CN (see figure) exhibits a thermally-induced electron-transfer-coupled spin transition between the two states: {{{\rm {\rm Co}}{{{\rm {\rm II}}\hfill \atop {\rm {\rm H...

A repeatable bidirectional paramagnetic ↔ diamagnetic photomagnetic effect has been observed in the cyanide-bridged Fe–Co square complex {[Fe{B(pz)4}(CN)3]2[Co(bik)2]2}(ClO4)2·3H2O [B(pz)4 = tetrapyrazolylborate, bik = bis(1-methylimidazol-2-yl)ketone]. Magnetic measurements and low-temperature single-crystal X-ray diffraction experiments have show...

Combining serendipitously-formed hydroxo-clusters, [Co(II)(3)(OH)(piv)(4)(L)](+) (where L = MeCN or Hpiv), with assembling cyanide building block, [Fe(III)(Tp)(CN)(3)](-), has led to an unprecedented architecture where polymetallic cobalt clusters and blocked tris-cyanide iron complexes define the apexes of a unique magnetic cubic nanocage.

Two metallacyclic complexes of general formula Na8[MII2L3][middle dot]xH2O [M = Ni (4) and Co (5) with x = 15 (4) and 17 (5)] have been self-assembled in aqueous solution from N,N[prime or minute]-1,3-phenylenebis(oxamic acid) (H4L) and M2+ ions in a ligand/metal molar ratio of 3 : 2 in the presence of NaOH acting as base. X-Ray structural analyses...

The self-assembly of [Fe(III)(Tp)(CN)(3)](-) and [Fe(II)(bik)(2)(S)(2)](2+) affords the cyanide-bridged mixed valence {Fe(III)(2)Fe(II)(2)}(2+) molecular square, which exhibits a photomagnetic effect under laser light irradiation at low temperature and also shows thermal spin-state conversion near ambient temperature.

A new series of neutral oxamato-bridged M(II)Cu(II) chiral chains of general formula [MCuL(x)(S)(m)(H(2)O)(n)]·aS·bH(2)O [L(1)=(M)-1,1'-binaphthalene-2,2'-bis(oxamate) with M=Mn (1a) and Co (1b); L(2)=(P)-1,1'-binaphthalene-2,2'-bis(oxamate) with M=Mn (2a) and Co (2b)] and the analogous racemic chains of formula [MCuL(3)(S)(m)(H(2)O)(n)]·aS·bH(2)O...

Magic-angle spinning (MAS) NMR spectroscopy is used to study the local structure and spin delocalisation in Prussian blue analogues (PBAs). We selected two common archetypes of PBAs (A(I)M(II)[M(III)(CN)(6)]·xH(2)O and M(II)(3)[M(III)(CN)(6)](2)·xH(2)O, in which A(I) is an alkali ion, and M(II) and M(III) are transition-metal ions) that exhibit sim...

The self-assembly of the partially blocked fac-[FeIII(L-L-L)(CN)3]− and cis-[MII(L-L)2(S)2]2+ (M = Mn, Ni, Co) building blocks provides a safe route toward the synthesis of heterometallic FeIII2MII2 square complexes. Their magnetic properties reveal the occurrence of an efficient magnetic exchange interaction between the metal ions through the cyan...

Double-stranded copper(II) string complexes of varying nuclearity, from di- to tetranuclear species, have been prepared by the Cu(II)-mediated self-assembly of a novel family of linear homo- and heteropolytopic ligands that contain two outer oxamato and either zero (1 b), one (2 b), or two (3 b) inner oxamidato donor groups separated by rigid 2-met...

A new metallosupramolecular functional complex… … with a meso-helical structure has been prepared through the side-by-side self-assembly of two linear heterotopic oligo-m-phenyleneoxalamide ligands by four CuII ions. The unique redox and ferromagnetic properties are described by Y. Journaux, F. Lloret et al. in their Full Paper on page 12838 ff.

Two new heterometallic Ni(II)(n)Cu(II)((9-n)) complexes [n = 1 (2) and 2 (3)] have been synthesized following a multicomponent self-assembly process from a n:(3 - n):2:6 stoichiometric mixture of Ni(2+), Cu(2+), L(6-), and [CuL'](2+), where L and L' are the bridging and blocking ligands 1,3,5-benzenetris(oxamate) and N,N,N',N'',N''-pentamethyldieth...

The impressive potential of the metallosupramolecular approach in designing new functional magnetic materials constitutes a great scientific challenge for the chemical research community that requires an interdisciplinary collaboration. New fundamental concepts and future applications in nanoscience and nanotechnology will emerge from the study of...

The self-assembly of [Fe(III){B(pz)(4)}(CN)(3)](-) and [Co(II)(bik)(2)(S)(2)](2+) affords the diamagnetic cyanide-bridged [Fe(II)(LS)Co(III)(LS)](2) molecular square which is converted into the corresponding magnetic [Fe(III)(LS)Co(II)(HS)](2) species under light irradiation at relatively low temperatures.

A new 1D coordination polymer comprised of [Mn(III)(6)O(2)(Et-sao)(6)(EtOH)(4)(H(2)O)(2)](2+) units and bithiophene dicarboxylato was synthesized by mixing EtsaoH(2) (salicylaldoxime), H(2)btda (2,2'-bithiophene-5,5'-dicarboxylic acid) and Mn(ClO(4))(2)·6H(2)O in the presence of NEt(4)OH. The crystal structure was determined and consists of Mn(6) c...

Homo- and heterometallic octanuclear complexes of formula Na₂{[Cu₂(mpba)₃][Cu(Me₅dien)]₆}-(ClO₄)₆·12H₂O (1), Na₂{[Cu₂(Mempba)₃][Cu(Me₅dien)]₆}(ClO₄)₆·12H₂O (2), Na₂{[Ni₂(mpba)₃]-[Cu(Me₅dien)]₆}(ClO₄)₆·12H₂O (3), Na₂{[Ni₂(Mempba)₃][Cu(Me₅dien)]₆}(ClO₄)₆·9H₂O (4), {[Ni₂(mpba)₃][Ni(dipn)(H₂O)]₆}(ClO₄)₄·12.5H₂O (5), and {[Ni₂(Mempba)₃][Ni(dipn)-(H₂O)]₆...

The self-assembly of an enantiomerically pure, chiral dianionic oxamatocopper(II) complex with cobalt(II) ions leads to neutral oxamato-bridged heterobimetallic chains that combine chirality and slow magnetic relaxation, providing thus the first example of "chiral single chain magnets" (CSCMs).

Two isostructural heterometallic trinuclear oxalato-bridged complexes of formula C(4)[MCr(2)(ox)(6)(H(2)O)(2)]·nH(2)O (C(+) = 4-aminopyridinium; ox(2-) = oxalate dianion; M(2+) = Mn(2+), n = 3, 1; M(2+) = Co(2+), n = 3.25, 2) have been synthesized by using direct self-assembly methods combining C(3)[Cr(ox)(3)] and the chloride salts of the correspo...

A series of trinuclear copper(II) complexes of general formula A(6)[Cu(3)L(2)] x nH(2)O [L = benzene-1,3,5-tris(oxamate); A = Li(+) (n = 8), 1a; Na(+) (n = 11.5), 1b; and K(+) (n = 8.5), 1c] have been synthesized, and they have been structurally and magnetically characterized. X-ray diffraction on single crystals of 1c shows the presence of three s...

The rational preparation of both homo- and heterometallic, tetranuclear Cu2M2 racks (M = CuII and NiII) presented herein is based on the heteropolytopic nature of the linear, tetranucleating phenylenedioxamato bridging ligands (L) and the presence of different aliphatic bi- and tridentate polyamines as terminal ligands (L′); their magnetic behavior...

No legendary Prussian order! The distribution of vacancies in Prussian blue analogues is not random, and the spin density on the Cd(2+) ion varies depending on the number of paramagnetic ions in its surroundings. This conclusion follows from (113)Cd solid-state magic-angle spinning NMR studies of [Cd(3){Fe/Co(CN)(6)}(2)] x 15 H(2)O, where the prese...

Keine legendäre preußische Ordnung! Leerstellen sind in Preußischblau-Analoga nicht zufällig verteilt, und die Spindichte am Cd2+ variiert mit der Zahl an umgebenden paramagnetischen Ionen. Dies ergaben Festkörper-113Cd-NMR-Studien an [Cd3{Fe/Co(CN)6}2]⋅15 H2O, in denen das Vorliegen einer geringen, aber signifikanten Spindichte an den beobachteten...

The reaction of the iron(III) unit fac-[Fe{HB(pz)3}(CN)3]−[HB(pz)3-=hydrotris(1-pyrazolyl)borate] as the lithium salt (1) with the nickel(II) complex mer-[Ni(dpt)(H2O)3](ClO4)2 [dpt = dipropylenetriamine] in water affords the heterometallic compound of formula {[FeIII{HB(pz)3}(CN)3]2[NiII(dpt)]}n · 3nH2O (2). The structure of 2 has been determined...

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Two new series of oxamato-bridged heterobimetallic coordination networks of general formula Li5[Li3M2(mpba)3(H2O)6]·31H2O [M=NiII (1a) and CoII (1b)] and Li2[Mn3M2(mpba)3(H2O)6]·22H2O [M=NiII (2a) and CoII (2b)] have been prepared from the metal-mediated self-assembly of the hexakis(bidentate), triple-stranded dinickel(II) and dicobalt(II) complexe...

The aim and scope of this review is to show the general validity of the 'complex-as-ligand' approach for the rational design of metallosupramolecular assemblies of increasing structural and magnetic complexity. This is illustrated herein on the basis of our recent studies on oxamato complexes with transition metal ions looking for the limits of the...