Hysteresis Photomodulation within photochromic assemblies of [Dy(Tp2-py)F]+ Single-Molecule Magnets : Influence of the supramolecular magnetic couplings.

A 1D coordination compound made of a photochromic dithienylethene linker and [Dy(Tp2-py)F]+ units (with Tp2-py = tris(3-(2-pyridyl)pyrazolyl)hydroborate) and having tetrakis[3,5-bis(trifluoromethyl)phenyl]borate counterions is reported. Full photoconversion from the closed isomer to the open isomer of the dithienyethene within single crystals allow for monitoring of the transformation by photocrystallography. Magnetic slow relaxation as well as magnetic hysteresis are observed and can be both modulated upon light irradiation.

Halogen-Bonds-Based Strategy for the Design of Highly Luminescent Lanthanide Coordination Polymers as Taggants for Plastic Waste Sorting.

Reactions in water between a lanthanide ion and 3,4,5,6-tetrachloro-phthalate lead to a new series of iso-structural coordination polymers with general chemical formula [Ln(tcpa)(HO)] with Ln = Eu-Yb plus Y. The crystal structure has been solved on the Y-derivative. This compound crystallizes in the monoclinic system, space group 2/ (no.

Kinetic Delay in Cooperative Supramolecular Polymerization by Redefining the Trade-Off Relationship between H-Bonds and Van der Waals/π-π Stacking Interactions.

We here present how rebalancing the interplay between H-bonds and dispersive forces (Van der Waals/π-π stacking) may induce or not the generation of kinetic metastable states. In particular, we show that extending the aromatic content and favouring the interchain VdW interactions causes a delay into the cooperative supramolecular polymerization of a new family of toluene bis-amide derivatives by trapping the metastable inactive state.

Isotopic enrichment in lanthanide coordination complexes: contribution to single-molecule magnets and spin qudit insights.

Lanthanide Single-Molecule Magnets (SMMs) fascinate the scientific community due to their plethora of potential applications ranging from data storage to spintronic devices and quantum computing. This review article proposes a comprehensive description of the influence of the nuclear spin, hyperfine interaction, on the magnetic properties of lanthanide SMMs and on quantum information processing of qudit. This influence is analysed for non-Kramers and Kramers lanthanide SMMs as well as for the electronic distribution of the electron in 4f orbitals oblate and prolate ions.

A photochromic metallacycle with highly anisotropic Dy-F magnetic units.

A dinuclear metallacycle assembled from a bispyridyl dithienylethene linker and a highly anisotropic dysprosium based Single Molecule Magnet (SMM) shows magnetic hysteresis at 1.8 K together with photoisomerization in single crystals (SC). The impact of photoswitching on the SMM behavior is evidenced and related to the specific organization of the magnetic units.

Lanthanide-Based Coordination Polymers Molecular Alloys Stability: A Thermochemical Approach.

In this study, we investigate the thermodynamics of lanthanide-based coordination polymer molecular alloys. We demonstrate that if lanthanide ions have many chemical similarities, the solubility of homo-lanthanide-based coordination polymers can vary significantly from one lanthanide ion to another. Indeed, we experimentally determine the solubility constants of a series of isostructural homo-lanthanide coordination polymers, with general chemical formula [Ln(bdc)(HO)] with Ln = La-Er plus Y and where bdc symbolizes 1,4-benzene-di-carboxylate.

Building Connections to Biology and Community through Service-Learning and Research Experiences.

Service-learning and undergraduate research experiences are high-impact practices that have become more common in the sciences, but the benefits of short-term experiences have not been thoroughly investigated. The purpose of this study was to compare within-semester gains for students in a short-term service-learning (SL) or short-term research project (RP) in terms of students' (i) motivation to learn biology, (ii) scientific literacy, (iii) perception of the relevance of biology to their lives, and (iv) learning gains associated with course learning outcomes. The impacts of brief service-learning and research project experiences were compared using direct and indirect assessments, including qualitative coding of open-ended response questions and quantitative analysis of exams and Likert-type items.

Metallogels: a novel approach for the nanostructuration of single-chain magnets.

In this study we demonstrate that single-chain magnets (SCMs) can be assembled in gel phase and transferred intact on surface. We take advantage of a family of SCMs based on Tb ions and nitronyl-nitroxides radicals functionalized with short alkyl chains known to form crystalline supramolecular nanotubes interacting with heptane acting as crystallizing solvent. When the radicals are functionalized with long aliphatic chains a robust gel is formed with similar structural and functional properties respect to its crystalline parent.

Luminance and Brightness: Application to Lanthanide-Based Coordination Polymers.

Measuring the luminance of lanthanide-based coordination polymers under UV excitation is of prime importance for many technological applications. This study highlights that the quantum yield gives no information about the luminescence intensity of a solid-state compound. Indeed, compounds with high quantum yield can actually be poorly luminescent.

Investigation of Intermetallic Energy Transfers in Lanthanide Coordination Polymers Molecular Alloys: Case Study of Trimesate-Based Compounds.

Reactions in water at ambient temperature and pressure between a lanthanide ion and benzene-1,3,5-tricarboxylate (or trimesate) lead to two series of iso-structural coordination polymers. Their general chemical formula is [Ln(tma)(HO)] for the lightest lanthanide ions (Ln = La-Dy except ), while it is [Ln(tma)(HO)·3.5HO] for the heaviest ones (Ho-Lu plus Y).

Synthesis, Crystal Structure, and Luminescence Properties of the Iso-Reticular Series of Lanthanide Coordination Polymers Synthesized from Hexa-Lanthanide Molecular Precursors.

Microwave-assisted reactions in DMSO, between a hexa-lanthanide octahedral complex ([Ln(μ-O)(μ-OH)(NO)(HO)·2NO·2HO] with Ln = Nd-Yb plus Y) and either 3-halogenobenzoic acid (hereafter symbolized by 3-bH with = f or c for fluoro or chloro, respectively) or 4-halogenobenzoic acid (hereafter symbolized by 4-bH with = f, c, or b for fluoro, chloro, or bromo, respectively), lead to 1D lanthanide coordination polymers. These coordination polymers are almost iso-reticular. The crystal structure is described on the basis of the coordination polymer with chemical formula [Tb(4-fb)(DMSO)(HO)·DMSO] obtained from 4-fluorobenzoic acid (4-fbH) and the Tb-based octahedral complex: It crystallizes in the triclinic system, space group 1̅ (n°2), with the following cell parameters: = 9.

Hexanuclear Molecular Precursors as Tools to Design Luminescent Coordination Polymers with Lanthanide Segregation.

Solvothermal reactions between hexanuclear complexes with the general chemical formula [Ln(μ-O)(μ-OH)(NO)(HO)]·2NO·2HO and 2-bromobenzoic acid (2-bbH) lead to a series of isostructural one-dimensional coordination polymers with the general chemical formula [Ln(2-bb)] with Ln = Sm, Eu, Tb, Dy, and Y. These coordination polymers crystallize in the orthorhombic space group 2 (No. 43) with the following cell parameters: = 29.

Using Community-Based Participatory Research to Characterize Health and Lifestyle Behaviors of Montagnards, a Refugee-Origin Asian-American Subgroup.

Montagnards, an indigenous multitribal refugee-origin population concentrated in North Carolina, remain an invisible, medically underserved, and socioeconomically underrepresented Asian American sub-group. Yet this group is resilient, with language diversity, rich cultural traditions and family caregiving in multigenerational households. Using community-based participatory research methods, we developed and administered a two-part survey to 144 Montagnard adults, documenting socioeconomic characteristics, health indicators and lifestyle behaviors.

Single-chain magnet behavior in a finite linear hexanuclear molecule.

The careful monitoring of crystallization conditions of a mixture made of a Tb building block and a substituted nitronyl-nitroxide that typically provides infinite coordination polymers (), affords a remarkably stable linear hexanuclear molecule made of six Tb ions and five NIT radicals. The are double-bridged by water molecules but calculations demonstrate that this bridge is inefficient in mediating any magnetic interaction other than a small dipolar antiferromagnetic coupling. Surprisingly the , despite being finite molecules, show a single-chain magnet (SCM) behavior.

Solvato Modulation of the Magnetic Memory in Isotopically Enriched Erbium Polyoxometalate.

Single-Molecule Magnet (SMM) property is by essence molecular, while commonly measured in solid crystalline state. Solvent crystallization molecules are usually neglected in the analysis and interpretation of solid-state properties. The solvation/desolvation process in the polyoxometalate(POM)-based Na [Er(W O ) ] ⋅ 35 H O SMM demonstrates that the dehydrated form relaxes more than 1000 times faster than the initial state, while the rehydration process allows the quasi complete recovering of the initial magnetic behaviour.

Highly Luminescent Europium-Based Heteroleptic Coordination Polymers with Phenantroline and Glutarate Ligands.

Isostructural lanthanide-based coordination polymers with general chemical formula [Ln(phen)(glu)(NO)] with Ln = La-Tm (except Ce and Pm) have been synthesized by hydrothermal methods (Hglu stands for glutaric acid and phen stands for 1,10-phenantroline). They crystallize in the monoclinic system with the 2/ (no. 14) space group.

A Journey in Lanthanide Coordination Chemistry: From Evaporable Dimers to Magnetic Materials and Luminescent Devices.

ConspectusLanthanide ions are prime ingredients for the design of compounds, materials, and devices with unique magnetic and optical properties. Accordingly, coordination chemistry is one of the best tools for building molecular edifices from these ions because it allows careful control of the ions' environment and of the dimensionality of the final compound.In this Account, we review our results on lanthanide-based dimers.

High Luminance of Heterolanthanide-Based Molecular Alloys by Phase-Induction Strategy.

Reactions in water of lanthanide chlorides with the sodium salt of 4,5-dichlorophthalate (dcpa) lead to two families of isostructural coordination polymers: family that gathers compounds with the general chemical formula [Ln(dcpa)(HO)] with Ln = La-Gd (except Pm) and family that gathers compounds with general chemical formula [Ln(dcpa)(HO)·3HO] with Ln = Tb-Lu plus Y. Heterolanthanide molecular alloys that contain both Eu and Tb ions have been prepared in both structural families. Their luminescence properties have been studied, especially from the brightness point of view.

Rational Design of Dual IR and Visible Highly Luminescent Light-Lanthanides-Based Coordination Polymers.

A series of isostructural homo- and heterolanthanide coordination polymers of formula [Ln(dcpa)(HO)] with Ln = La-Gd have been obtained by reactions in water between the lightest lanthanide chlorides and the disodium salt of 4,5-dichlorophthalic acid (Hdcpa). They present particularly high thermal stability for coordination compounds (up to 400 °C). Their luminescent properties have been studied in detail.

Sonocrystallization as an Efficient Way to Control the Size, Morphology, and Purity of Coordination Compound Microcrystallites: Application to a Single-Chain Magnet.

The size, morphology, and purity control of coordination compound powders is a key stage for their conversion into materials and devices. In particular, surface science techniques require highly pure bulk materials with a narrow crystallite-size distribution together with straightforward, scalable, and reproducible crystallization procedures. In this work we demonstrate how sonocrystallization, i.

Fostering Inclusion through an Interinstitutional, Community-Engaged, Course-Based Undergraduate Research Experience.

Creation of an inclusive environment requires a culture of equity, justice, value and respect for diverse backgrounds, and opportunities for students to engage with communities while addressing issues in science and society. These tasks are particularly challenging for institutions lacking a diverse population. Here, we demonstrate evidence of a successful model for creating an inclusive environment in an interinstitutional course between a large, public, historically black institution and a small, private, primarily white institution.

Self-assembly of a terbium(III) 1D coordination polymer on mica.

The terbium(III) ion is a particularly suitable candidate for the creation of surface-based magnetic and luminescent devices. In the present work, we report the epitaxial growth of needle-like objects composed of [Tb(hfac)·2HO] (where hfac = hexafluoroacetylacetonate) polymeric units on muscovite mica, which is observed by atomic force microscopy. The needle-like shape mimics the structure observed in the crystalline bulk material.

Hysteresis Photomodulation via Single-Crystal-to-Single-Crystal Isomerization of a Photochromic Chain of Dysprosium Single-Molecule Magnets.

A one-dimensional coordination solid is synthesized by reaction of a bispyridyl dithienylethene (DTE) photochromic unit with the highly anisotropic dysprosium-based single-molecule magnet [Dy(Tp)F(pyridine)]PF. Slow magnetic relaxation characteristics are retained in the chain compound , and photoisomerization of the bridging DTE ligand induces a single-crystal-to-single-crystal transformation that can be monitored using photocrystallography. Notably, the resulting chain compound exhibits faster low-temperature relaxation than that of , which is apparent in magnetic hysteresis data collected for both compounds as high as 4 K.

Hetero-hexalanthanide Complexes: A New Synthetic Strategy for Molecular Thermometric Probes.

Reactions in solvothermal or microwave-assisted conditions between a hexanuclear rare-earth entity ([Ln] with Ln = Eu-Dy) and -halogeno-benzoic acids lead to three series of isostructural complexes with respective chemical formulas [Ln(μ-OH)(HO)(NO)(3-cb)]·4CHCN, [Ln(μ-OH)(HO)(NO)(3-bb)]·6CHCN, and [Ln(μ-OH)(HO)(NO)(3-ib)]·6CHCN, where 3-cb, 3-bb, and 3-ib represent 3-chloro-, 3-bromo-, and 3-iodo-benzoate, respectively. These three series of compounds are almost isostructural. Their luminescent properties, in the solid and solution states, have been studied in detail and compared.

Chiral Supramolecular Nanotubes of Single-Chain Magnets.

We report a single-chain magnet (SCM) made of a terbium(III) building block and a nitronyl-nitroxide radical (NIT) functionalized with an aliphatic chain. This substitution is targeted to induce a long-range distortion of the polymeric chain and accordingly it gives rise to chains that are curled with almost 20 nm helical pitch. They self-organize as a chiral tubular superstructure made of 11 chains wound around each other.