From Micro to Macro: Avian Chromosome Evolution is Dominated by Natural Selection.

Birds display striking variation in chromosome number, defying the traditional view of highly conserved avian karyotypes. However, the evolutionary drivers of this variability remain unclear. To address this, we fit probabilistic models of chromosome number evolution across birds, enabling us to estimate rates of evolution for total chromosome number and the number of microchromosomes and macrochromosomes while simultaneously accounting for the impact of other evolving traits.

Perspective on room temperature and low-field-induced magnetoelectric coupling in molecular complexes.

Magnetoelectric (ME) coupling refers to the interaction between electric and magnetic orders in materials. Based on ME coupling, the phenomenon that an external magnetic field induces electric polarization and an external electric field induces change in mangetization can be observed and is referred to as the ME effect. Examples of the ME effect include magnetodielectric (MD), magnetoferroelectric (MF), magnetoresistence (MR) and electrically controlled magnetism effects.

Effect of Substituents in Equatorial Hexaazamacrocyclic Schiff Base Ligands on the Construction and Magnetism of Pseudo Single-Ion Magnets.

Three mononuclear Dy compounds [DyL(PhSiO)][BPh]·MeCN·2HO (), [DyL(PhSiO)][BPh]·CHOH·HO (), and [DyL(PhSiO)(OAc)][BPh]·CHOH·3HO () and their corresponding Y diluted analogues [DyYL(PhSiO)][BPh]·MeCN·2HO (), [DyYL(PhSiO)][BPh]·CHOH·HO (), and [DyYL(PhSiO)(OAc)][BPh]·CHOH·3HO () were synthesized with hexaazamacrocyclic Schiff base ligands as an equatorial ligand. The substituents in the equatorial hexaazamacrocyclic Schiff base ligand show a significant effect on the replacement of the axial ligands. Compounds , , and are typical zero dc field single-molecule magnets with effective energy barriers () of 1092(6), 946.

Room-temperature Magnetocapacitance Spanning 97K Hysteresis in Molecular Material.

Magnetic capacitor, as a new type of device, has broad application prospects in fields such as magnetic field sensing, magnetic storage, magnetic field control, power electronics and so on. Traditional magnetic capacitors are mostly assembled by magnetic and capacitive materials. Magnetic capacitor made of a single material with intrinsic properties is very rare.

A Multiferroic Spin-Crossover Molecular Crystal.

Spin-crossover (SCO) ferroelectrics with dual-function switches have attracted great attention for significant magnetoelectric application prospects. However, the multiferroic crystals with SCO features have rarely been reported. Herein, a molecular multiferroic Fe(II) crystalline complex [Fe(C-F-pbh)] (1-F, C-F-pbh = (1Z,N'E)-3-F-4-(octyloxy)-N'-(pyridin-2-ylmethylene)-benzo-hydrazonate) showing the coexistence of ferroelectricity, ferroelasticity, and SCO behavior is presented for the first time.

Molecular ferroelectric with low-magnetic-field magnetoelectricity at room temperature.

Magnetoelectric materials, which encompass coupled magnetic and electric polarizabilities within a single phase, hold great promises for magnetic controlled electronic components or electric-field controlled spintronics. However, the realization of ideal magnetoelectric materials remains tough due to the inborn competion between ferroelectricity and magnetism in both levels of symmetry and electronic structure. Herein, we introduce a methodology for constructing single phase paramagnetic ferroelectric molecule [TMCM][FeCl], which shows low-magnetic-field magnetoelectricity at room temperature.

Synergetic Responses of Multiple Functions Induced by Phase Transition in Molecular Materials.

Materials that integrate magnetism, electricity and luminescence can not only improve the operational efficiency of devices, but also potentially generate new functions through their coupling. Therefore, multifunctional synergistic effects have broad application prospects in fields such as optoelectronic devices, information storage and processing, and quantum computing. However, in the research field of molecular materials, there are few reports on the synergistic multifunctional properties.

Near-Room-Temperature Synergetic Response of Magnetism, Dielectricity and Luminescence Based on (C NH Cl) MnBr.

Multifunctional materials with working temperatures near room temperature are crucial for practical applications. Until now, it is still a great challenge to obtain such materials. In this paper, a complex of (C NH Cl) MnBr (1) with a structural phase transition near room temperature is reported.

An Effective Strategy of Introducing Chirality to Achieve Multifunctionality in Rare-Earth Double Perovskite Ferroelectrics.

The hybrid rare-earth double perovskite (HREDP) system provides great convenience for the construction of multifunctional materials. However, suffering from the high symmetry of their intrinsic structure, HREDPs face the challenges in the realization and optimization of ferroelectric and piezoelectric properties. For the first time, after a systematic investigation of the chirality transformation principle, it is found that the introduction of chirality is an efficient strategy for the targeted construction of multifunctionality, which simultaneously increases the possibility of obtaining multiaxial ferroelectricity and ferroelasticity, and effectively realizes a large piezoelectric response.

Single-molecule magnet behaviour in a centrosymmetric dinuclear dysprosium(III) complex: sequential differentiation of triple relaxation pathways.

A dinuclear complex with the formula DyL(HL)Cl(EtOH) (Dy2) has been synthesized by reacting DyCl·HO with a ligand HL (HL = ,'-ethylenebis(salicylideneimine)) using ethanol as the solvent. Its crystal structure can be viewed as a dimer of two Dy(III) fragments, where each Dy(III) site shows a NOCl coordination sphere with a pentagonal bipyramid geometry (). Magnetic measurements reveal that Dy2 behaves as a single-ion magnet (SIM) under a zero field.

A cationic sulfur-hydrocarbon triradical with an excited quartet state.

The triptycene-bridged tris(thianthrene) compound 1 was designed and synthesized. Three-electron oxidation of 1 by NO[Al(OC(CF))], followed by crystallization at two different temperatures resulted in the triradical trication salts 2a and 2b respectively, which feature different crystal packing patterns. The triradical trications in 2a and 2b both feature a doublet ground state which can be thermally populated to a quartet state, representing the first examples of cationic main-group triradicals.

Indeno[2,1-a]fluorene-11,12-dione Radical Anions: Synthesis, Characterization, and Properties.

The one-electron reduction of indeno[2,1-a]fluorene-11,12-dione (IF) with various alkali metals prepare the radical anion salts. The data about different structures, properties, and characterization was obtained by single-crystal X-ray diffraction, electron paramagnetic resonance (EPR) spectroscopy, superconducting quantum interference device (SQUID) measurements, and physical property measurement system (PPMS). Compound IF K (18-c-6) is regarded as a one-dimensional magnetic chain through C-H⋅⋅⋅C interaction.

Significantly Enhancing the Single-Molecule-Magnet Performance of a Dinuclear Dy(III) Complex by Utilizing an Asymmetric Auxiliary Organic Ligand.

In this work, we employed an asymmetric auxiliary organic ligand (1,1,1-trifluoroacetylacetone, Htfac) to further regulate the magnetic relaxation behavior of series of Dy single-molecule magnets (SMMs) with a 1,3-bis(3-methoxysalicylidene)diethylenetriamine (HL) ligand. Fortunately, an air-stable Dy complex, [Dy(L)(tfac)] (; Htfac = 1,1,1-trifluoroacetylacetone) was obtained at room temperature. A structural analysis indicated that some Dy-O or Dy-N bond lengths for are not in the range of those for the complexes [Dy(L)(acac)]·2CHCl (; Hacac = acetylacetone) and [Dy(L)(hfac)] (; Hhfac = hexafluoroacetylacetone), although the electron-withdrawing ability of tfac is stronger than that of acac but weaker than that of hfac.

Reversible Switching of Single-Molecule Magnetic Behaviour by Desorption/Adsorption of Solvent Ligand in a New Dy(III)-Based Metal Organic Framework.

Two metal-organic frameworks (MOFs), [Dy(BDC)(NO)(DMF)] (, HBDC = terephthalic acid) and [Dy(BDC)(NO)] (), were synthesized. The structures of MOFs and are easy to be reversibly transformed into each other by the desorption or adsorption of coordination solvent molecules. Accordingly, their magnetic properties can also be changed reversibly, which realizes our goals of manipulating on/off single-molecule magnet behaviour.

A high-spin diradical dianion and its bridged chemically switchable single-molecule magnet.

Triplet diradicals have attracted tremendous attention due to their promising application in organic spintronics, organic magnets and spin filters. However, very few examples of triplet diradicals with singlet-triplet energy gaps (Δ ) over 0.59 kcal mol (298 K) have been reported to date.

Influence of the Different Types of Auxiliary Noncarboxylate Organic Ligands on the Topologies and Magnetic Relaxation Behavior of Zn-Dy Heterometallic Single Molecule Magnets.

In this work, we first synthesized a Zn-Dy complex, [ZnDy(L)(tea)(CHOH)]·6CHOH·8HO (HL = -3-methoxysalicylidene-2-amino-3-hydroxypyridine, teaH = triethanolamine, ), by employing HL, anhydrous ZnCl, and Dy(NO)·5HO reacting with auxiliary ligand teaH in the mixture of CHOH and DMF. When teaH and the solvent CHOH in the reaction system of were replaced by the auxiliary ligand 2,6-pyridinedimethanol (pdmH) and the solvent MeCN, another Zn-Dy complex, [ZnDy(L)(pdm)(pdmH)]·10CHCN·5HO (), was obtained. For , its crystal structure can be viewed as a dimer of two ZnDy units.

Macrocyclic Chromium(III) Catecholate Complexes.

The synthesis and structural, electrochemical, spectroscopic, and magnetic characterizations of Cr(HMC) catecholate and semiquinonate complexes are reported herein, where HMC is 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane. [Cr(HMC)(Cat)] complexes (Cat = catecholate, []; tetrachlorocatecholate, []; and 3,5-di--butylcatecholate, []) were prepared from the reaction between appropriate catechol and [Cr(HMC)Cl]Cl reduced by zinc. Chemical oxidation of [] by FcPF resulted in -[Cr(HMC)(SQ)] ([], SQ = 3,5-di--butylsemiquinonate).

Guest-Induced Switching of a Molecule-Based Magnet in a 3d-4f Heterometallic Cluster-Based Chain Structure.

With the motivation of controlling a magnetic switch by external stimuli, we report here an infinite chain structure formed from the secondary building units of CuTb clusters through the linkage of nitrate ions. It behaves as a molecule-based magnet with the highest energy barrier among isolated Tb/Cu-based single-molecule magnets and single-chain magnets, which is close to a dimer of a CuTb cluster unit from a magnetic point as revealed by its correlation length of 2.23 CuTb units.

Structurally modulated single-ion magnets of mononuclear β-diketone dysprosium(III) complexes.

Five β-diketone based Dy(iii) single-ion magnets (SIMs), [DyIII(TTA)3(AIP)]·0.5CH3CH2OH·0.5H2O (1), [DyIII(TTA)3(APIP)]·2CH3OH·H2O (2), [DyIII(TTA)3(DPP)] (3), [DyIII(TTA)3(BPP)]·0.

Synthesis, crystal structures, HF-EPR, and magnetic properties of six-coordinate transition metal (Co, Ni, and Cu) compounds with a 4-amino-1,2,4-triazole Schiff-base ligand.

We have synthesized a series of transition metal compounds [M(L)(HO)] (M = Co (1), Ni (2), and Cu (3)) by using the 4-amino-1,2,4-triazole Schiff-base ligand the hydrothermal methods. They are all mononuclear compounds with the octahedral geometry. Direct-current magnetic and HF-EPR measurements were combined to reveal the negative values (-28.

Optimal diamagnetic dilution concentration for suppressing the dipole-dipole interaction in single-ion magnets.

The effect of screening the Co moment of monomeric [CoL(HO)] (L = 8-hydroxyquinaldine), having a trigonal bipyramid coordination, by diamagnetic Zn in CoZn solid solutions on its magnetic relaxation was explored using ac-susceptibility, high-field electron-spin-resonance measurements and CASPT2 calculations. The retention of the crystal structure for all the solid solutions was demonstrated using single crystal diffraction. The dc-magnetization and theoretical fittings of the susceptibility for Co and CoZn gave a large zero-field-splitting (ZFS) D of 50 ± 6 cm, and very weak dipole interaction between the nearest neighbors, while EPR and calculations confirmed the positive sign of the axial component (D).

Narrow Band Gap Observed in a Molecular Ferroelastic: Ferrocenium Tetrachloroferrate.

Due to the intriguing chemical variability and structure-property flexibility, molecular materials with striking multifunctional characteristics, including tunable physical, chemical, optical, and electronic properties, have aroused wide attention. Recently, great advances have also been made in designing molecular ferroelastics with optoelectronic properties. However, the band gaps of the most typical ferroelastics are far in excess of 2.

Light-controlled efficient photoluminescence based on an europium β-diketonate complex with single-crystal-to-single-crystal [2+2] cycloaddition.

A brand new europium(iii) β-diketonate complex undergoes a single-crystal-to-single-crystal transformation via [2+2] cycloaddition after UV irradiation, triggering strong Eu(iii) red emission turn-on, which is highly photostable even after 50 hours of irradiation. A photo-patterning process is successfully conducted for security printing application in materials science.

Synthesis, crystal structures and magnetic properties of a series of chair-like heterometallic [FeLn] (Ln = Gd, Dy, Ho, and Er) complexes with mixed organic ligands.

Four chair-like hexanuclear Fe-Ln complexes containing mixed organic ligands, namely, [FeLn{(py)CO}(pdm)(NO)(HO)Cl]·xCHCN·yHO (Ln = Gd (1, x = 1, y = 0), Dy (2, x = 1, y = 1), Ho (3, x = 0, y = 2), and Er (4, x = 1, y = 3); (py)COH = the gem-diol form of di-2-pyridyl ketone and pdmH = 2,6-pyridinedimethanol) have been obtained by employing di-2-pyridyl ketone and 2,6-pyridinedimethanol reacting with FeCl and Ln(NO) in MeCN. The structures of 1-4 are similar to each other except for the number of lattice solvent molecules. Four Fe and two Ln in these complexes comprise a chair-like core with the "body" constructed by four Fe ions and the "end" constructed by two Ln ions.