jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Hamida Jelali | Ahlem Chakchouk Mtibaa | Lassaad Baklouti | Hallouma Bilel | Yaser Bathich | Lotfi Mellouli | Naceur Hamdi
Source: Journal of Chemistry (article, 2019-08-21)
Field: Chemistry — Organic Chemistry

Development of New Multicomponent Reactions in Eco-Friendly Media-Greener Reaction and Expeditious Synthesis of Novel Bioactive Benzylpyranocoumarins Multicomponent cyclocondensation of hydrazine derivatives, ethyl acetoacetate, aromatic aldehydes, and 4-hydroxycoumarin has been reported. The optimization details of the developed novel protocol are recorded. The novel procedure features short reaction time, moderate yields, and simple workup. In addition, BMIM[triflate] was chosen as a green solvent. The structures of the obtained benzylpyrazolyl coumarins were determined and confirmed by 1 H NMR, 13 C NMR, IR, and elemental analysis. The MIC values of benzylpyrazolyl coumarin derivatives were determined by the microbroth dilution method using 96-well plates. However, the derivatives 5a , 5b , 5d , and 5g possess the strongest activities. Compound 5b was the most active derivative against Candida albicans . Moreover, the antioxidant activity determination of these coumarins derivatives 5 ( a – g )– 6 ( a – g ) were studied with the DPPH and compared with gallic acid (GA)and butylated hydroxytoluene (BHT). Molecular modelling studies using DFT (density functional theory) calculations showed that there two tautomers A and B in which A is more stable than B . The benzylpyrazolyl coumarin derivatives 5e and 6f exhibited the most cytotoxic effect on the promising cytotoxic activity with IC50 values 4.45 μ g/mL against MDA-MB-231 and 4.85 μ g/mL against MCF7, respectively. Chemistry ; Ethyl acetoacetate ; Coumarin ; DPPH ; Gallic acid ; Butylated hydroxytoluene ; Hydrazine (antidepressant) ; Organic chemistry ; Proton NMR ; Knoevenagel condensation ; Combinatorial chemistry ; Antioxidant ; Catalysis ; Chromatography Multicomponent Synthesis of Heterocycles ; Synthesis and biological activity ; Synthesis of Organic Compounds
Authors: İdi̇l Çeti̇n | Pınar ERASLAN ELMA | Mehmet Topçul | Nilgün Karalı
Source: Istanbul Journal of Pharmacy (article, 2019-10-11)
Field: Chemistry — Organic Chemistry

Anticancer activities and cell death mechanisms of 1H-indole-2,3-dione 3-[N-(4 sulfamoylphenyl)thiosemicarbazone] derivatives In this study, the cytotoxic effects of 1H-indole-2,3-dione 3-[N-(4-sulfamoylphenyl)thiosemicarbazone derivatives namely, 4a-d were evaluated using cell kinetic parameters including the cell index, mitotic index, labelling index and apoptotic index on HeLa cells taken from a human cervix carcinoma. All compounds were evaluated using cell index parameters at 5, 10, 20, 40, 80, 100 and 160 μM concentrations. As a result of this, it was seen that all 4a-d compounds were effective in different concentrations. Different cell death mechanisms were proposed for 4a-d. When all the parameters were examined, it was found that the bromine substituted 4c was the most potent antiproliferative compound in the tested compounds. The difference was significant between the control and experimental groups (p&lt;0.01). In addition, a statistically significant difference was noted among all experimental groups (p&lt;0.01). HeLa ; Semicarbazone ; Mitotic index ; Indole test ; Apoptosis ; Chemistry ; Programmed cell death ; Labelling ; Significant difference ; Carcinoma Cell ; Cytotoxic T cell ; Stereochemistry ; Cell ; Biochemistry ; Mitosis ; Biology ; Medicine ; Internal medicine ; In vitro ; Cell biology Synthesis and biological activity ; Synthesis and Characterization of Heterocyclic Compounds ; Phenothiazines and Benzothiazines Synthesis and Activities
Authors: Haili Shi | Bo Lou | Mies J. van Steenbergen | Niels J. Sijbrandi | Wim E. Hennink | Robbert J. Kok
Source: Particle & Particle Systems Characterization (article, 2019-07-28)
Field: Materials Science — Biomaterials

Polymeric Micelles Employing Platinum(II) Linker for the Delivery of the Kinase Inhibitor Dactolisib Abstract Polymeric micelles are attractive nanocarriers for hydrophobic drug molecules such as the kinase inhibitor dactolisib. Two different poly(ethylene glycol)–poly(acrylic acid) (PEG‐ b ‐PAA) block‐copolymers are synthesized, PEG(5400)‐ b ‐PAA(2000) and PEG(10000)‐ b ‐PAA(3700), respectively. Polymeric micelles are formed by self‐assembly once dactolisib is conjugated via the ethylenediamine platinum(II) linker (Lx) to the PAA block of the block copolymers. Dactolisib micelles with dactolisib loading content of 17% w/w show good colloidal stability and display sustained release of Lx‐dactolisib over 96 h in PBS at 37 °C, while media containing reagents that compete for platinum coordination (e.g., glutathione (GSH) or dithiothreitol (DTT)) effectuate release of the parent inhibitor dactolisib at similar release rates. Dactolisib/lissamine‐loaded micelles are internalized by human breast adenocarcinoma cells (MCF‐7) in a dose and time‐dependent manner as demonstrated by confocal microscopy. Dactolisib‐loaded micelles inhibit the PI3K/mTOR signaling pathway at low concentrations (400 × 10 −9 m ) and exhibit potent cytotoxicity against MCF‐7 cells with IC 50 values of 462 ± 46 and 755 ± 75 × 10 −9 m for micelles with either short or longer PEG‐ b ‐PAA block lengths. In conclusion, dactolisib loaded PEG‐ b ‐PAA micelles are successfully prepared and hold potential for nanomedicine‐based tumor delivery of dactolisib. Micelle ; Ethylene glycol ; Chemistry ; Nanocarriers ; PEG ratio ; Dithiothreitol ; Copolymer ; Linker ; Drug delivery ; Biophysics ; Nuclear chemistry ; Polymer chemistry ; Combinatorial chemistry ; Organic chemistry ; Polymer ; Aqueous solution Nanoparticle-Based Drug Delivery ; Dendrimers and Hyperbranched Polymers ; Graphene and Nanomaterials Applications
Authors: Yoshimitsu Sagara | Kiyonori Takahashi | Takayoshi Nakamura | Nobuyuki Tamaoki
Source: Molecular Systems Design & Engineering (article, 2019-09-02)
Field: Materials Science — Materials Chemistry

Crystal structure and thermoresponsive luminescence of a 9,10-bis(phenylethynyl)anthracene-based cyclophane The crystal structure of a cyclophane that exhibits a supercooled nematic phase and thermoresponsive luminescence was solved. Anthracene ; Luminescence ; Cyclophane ; Crystal structure ; Photochemistry ; Chemistry ; Materials science ; Crystallography ; Optoelectronics Luminescence and Fluorescent Materials ; Supramolecular Chemistry and Complexes ; Synthesis and Properties of Aromatic Compounds
Authors: Tetsuhiko Takabatake | Takumi Yoneda | Jyo Otsuka | Natsuko Kagawa | Masahiro Toyota
Source: Tetrahedron Letters (article, 2019-07-17)
Field: Chemistry — Organic Chemistry

Artificial intelligence designed drug synthesis: One-pot preparation of trans β-lactams and application to cholesterol absorption inhibitor SCH 47949 synthesis Chemistry ; Stereoselectivity ; Lactam ; Yield (engineering) ; Ring (chemistry) ; Combinatorial chemistry ; Chemical synthesis ; Stereochemistry ; Organic chemistry ; Catalysis ; In vitro ; Biochemistry Synthesis of β-Lactam Compounds ; Cancer Treatment and Pharmacology ; Synthesis and Biological Activity
Authors: Aaron E. Tallman | Laura Swiler | Yan Wang | David L. McDowell
Source: Modelling and Simulation in Materials Science and Engineering (article, 2019-05-22)
Field: Materials Science — Materials Chemistry

Hierarchical top-down bottom-up calibration with consideration for uncertainty and inter-scale discrepancy of Peierls stress of bcc Fe Abstract A hierarchical multiscale model of plasticity in single crystal bcc Fe, framed at the mesoscale pertaining to a statistically representative set of dislocations for each slip system, relies on specification of a set of parameters which are informed using both bottom-up (BU) (atomistic) and top-down (TD) (experimental) information. We term this specification process a ‘connection’ between BU and TD pathways to inform the mesoscale model. The connection is considered in the presence of error, uncertainty, and discrepancy between the models. We expand upon a previously developed reconciled TD and BU calibration method to account for anticipated discrepancy between information from different length scales. The results of a previously formulated likelihood-based connection test of the multiscale model suggest a ‘missing link’ may be responsible for part of the inter-scale discrepancy. In this case, this link is assumed to be a relation between the unit-process (single dislocation line) of coordinated kink-pair nucleation on a screw dislocation segment and the many-body dislocation process which manifests in the onset of experimentally observed plastic deformation in a single crystal. A physics-informed discrepancy layer is formulated to improve the connection in the presence of additional persistent uncertainties. This physics-informed hypothesis testing is demonstrated as an alternative to fully data-driven search methods, particularly applicable to datasets of limited size that are often encountered in such multiscale material modeling applications. Discrete dislocation dynamics simulations are used to investigate the effect of the Peierls stress on straight screw dislocations and in the operation of Frank–Read sources. Discussion concerns the critical role of uncertainty quantification in providing a basis for this form of incremental hypothesis testing. Dislocation ; Mesoscale meteorology ; Nucleation ; Connection (principal bundle) ; Statistical physics ; Materials science ; Scale (ratio) ; Calibration ; Slip (aerodynamics) ; Plasticity ; Stress (linguistics) ; Set (abstract data type) ; Computer science ; Physics ; Geometry ; Mathematics ; Thermodynamics ; Statistics Microstructure and mechanical properties ; Rock Mechanics and Modeling ; Model Reduction and Neural Networks
Authors: Mohammad Javad Ziabakhsh Ganji | Mehdi Bigdeli | Davood Azizian
Source: International Journal of Engineering (article, 2019-05-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Mitigation Transformer Inrush Current Using Modified Transient Current Limiter This study presents a modified transient current limiter (MTCL) for mitigation the inrush current of transformers. The MTCL is based on conventional transient current limiter (TCL), which, its configuration is modified to overcome the TCL drawbacks of operation. The proposed MTCL offers lower power losses and voltage/current THD during normal operation mode. It needs only one limiting reactor instead of two limiting reactors, which results in cost saving. The theoretical analysis of the MTCL for suppressing the inrush current has been presented and the performance was tested by PSCAD/EMTDC simulation anda experimental prototype. Both simulation and experimental results showed that the MTCL is effective for suppressing the transformer inrush current. Also, the capability of the MTCL for suppressing the transformer inrush current was compared with the conventional TCL. Inrush current ; Current limiting ; Transformer ; Limiter ; Limiting ; Transient (computer programming) ; Engineering ; Current (fluid) ; Total harmonic distortion ; Overcurrent ; Voltage ; Fault current limiter ; Electronic engineering ; Electrical engineering ; Computer science ; Control theory (sociology) ; Power (physics) ; Electric power system ; Mechanical engineering ; Physics Magnetic Properties and Applications ; Non-Destructive Testing Techniques ; Power Systems Fault Detection
Authors: Han Liu | Zipeng Fu | Yipeng Li | Nazreen Farina Ahmad Sabri | Mathieu Bauchy
Source: arXiv (Cornell University) (preprint, 2019-02-09)
Field: Materials Science — Materials Chemistry

Machine Learning Forcefield for Silicate Glasses Developing accurate, transferable, and computationally-efficient interatomic forcefields is key to facilitate the modeling of silicate glasses. However, the high number of forcefield parameters that need to be optimized render traditional parameterization methods poorly efficient or potentially subject to bias. Here, we present a new forcefield parameterization methodology based on ab initio molecular dynamics simulations, Gaussian process regression, and Bayesian optimization. By taking the example of glassy silica, we show that our methodology yields a new interatomic forcefield that offers an unprecedented description of the atomic structure of silica. This methodology offers a new route to efficiently parameterize new empirical interatomic forcefields for silicate glasses with very limited need for intuition. Silicate ; Silicate glass ; Geology ; Geochemistry ; Materials science ; Artificial intelligence ; Computer science ; Mineralogy ; Chemical engineering ; Engineering Machine Learning in Materials Science ; Advanced X-ray and CT Imaging ; X-ray Diffraction in Crystallography
Authors: Vanessa Koehlé-Divo | Sandrine Pain-Devin | Carole Bertrand | Simon Devin | Catherine Mouneyrac | Laure Giambérini | Bénédicte Sohm
Source: Environmental Science and Pollution Research (article, 2019-03-29)
Field: Materials Science — Materials Chemistry

Corbicula fluminea gene expression modulated by CeO2 nanomaterials and salinity Corbicula fluminea ; Gill ; Salinity ; Context (archaeology) ; Ecotoxicology ; Biology ; Gene expression ; Toxicology ; Environmental chemistry ; Zoology ; Ecology ; Gene ; Chemistry ; Genetics ; Fish <Actinopterygii> ; Fishery Advanced Nanomaterials in Catalysis ; Nanoparticles: synthesis and applications ; Environmental Toxicology and Ecotoxicology
Authors: T. S. Serchenya | Dzmitry Shcharbin | Iryna Shyrochyna | О. В. Свиридов | Maria Terekhova | Volha Dzmitruk | Viktar Abashkin | Evgeny Apartsin | Serge Mignani | Jean‐Pierre Majoral | Максим Йонов | Maria Bryszewska
Source: Colloids and Surfaces B Biointerfaces (article, 2019-04-04)
Field: Materials Science — Polymers and Plastics

Immunoreactivity changes of human serum albumin and alpha-1-microglobulin induced by their interaction with dendrimers Dendrimer ; Chemistry ; Cationic polymerization ; In vivo ; In vitro ; Biophysics ; Human serum albumin ; Beta-2 microglobulin ; Serum albumin ; Albumin ; Biocompatibility ; Poly(amidoamine) ; Biochemistry ; Amidoamine ; Polymer chemistry ; Organic chemistry ; Biology ; Immunology Dendrimers and Hyperbranched Polymers ; RNA Interference and Gene Delivery ; Click Chemistry and Applications
Authors: Huan Huang | Zheng Liu | Lele Zhang | Xihong Guo | Rongli Cui | Jinquan Dong | Fei Chang | Shang‐Da Jiang | Song Gao | Baoyun Sun
Source: Carbon (article, 2019-10-31)
Field: Chemistry — Organic Chemistry

Paramagnetic properties adjustment for Gd@C(9)-C82 by regioselective multi-amination Paramagnetism ; Unpaired electron ; Morpholine ; Electron paramagnetic resonance ; Amination ; Chemistry ; Dodecahedron ; Gadolinium ; Spin (aerodynamics) ; Fullerene ; Crystallography ; Nuclear magnetic resonance ; Condensed matter physics ; Organic chemistry ; Catalysis ; Physics Fullerene Chemistry and Applications ; Graphene research and applications ; Diamond and Carbon-based Materials Research
Authors: Mo Ashafaq | Mohd Khalid | Mukul Raizada | Anzar Ali | Mohd Faizan | M. Shahid | Musheer Ahmad | Ray J. Butcher
Source: Crystal Growth & Design (article, 2019-02-25)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Crystal Engineering and Magnetostructural Properties of Newly Designed Azide/Acetate-Bridged Mn<sub>12</sub> Coordination Polymers Crystal engineering of the coordination polymers where polynuclear clusters are building blocks constitutes an emerging class of chemistry. The fine-tuning of the structural motifs leads to interesting and varying magnetic properties. Owing to such properties, two rare μ6-oxo centered mixed-valent, azide or acetate-bridged coordination polymers viz, [{MnII2MnIII10Na2(μ6-O)2(N3)10(NO3)(H2O)4(thme)8}·3(Et3NH)]n (1) and [{MnII3MnIII9Na7(μ2-O)2(μ6-O)2(O)5(CH3O)(CH3CO2)11(thmp)8}·4(O)]n (2), with retention of a Mn12 metallic core in both polymers are obtained using tripodal polyalcohol 1,1,1-tris (hydroxymethyl)ethane (H3thme) and 1,1,1-tris (hydroxymethyl)propane (H3thmp) ligands, respectively. X-ray analysis shows that 1 is a one-dimensional coordination polymer where Mn12 units are propagating by bridging azide function. 1 shows the underlying net of 2,2,3C6 topological type. 2 forms a cyclic ring as a result of repeating Mn12 zigzag chains bridging by sodium and H2O. The topology of 2 results in a 31-nodal underlying 3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,5,5,5,5,5,5,6,6,6,6,6,6,6,6,7,7-c net with a point symbol of the net of {3.4.5}2{3.47.52}2{32.410.52.6}{32.410.53}4{32.43.5.203.21}{32.43.5}6{32.44}2{32.46.52.63.7.8}{32.46.52}{34.44.52}{34.46.54.64.72.8}2{412.52.6}2{42.6}2{43}{45.5}3{45.6}{46.63.8}. In 1, a magnetic study ascertains the presence of antiferromagnetic interaction and shows single molecule magnet-like behavior with an energy barrier of 75.5 K. However, 2 exhibited strong antiferromagnetic interaction in dc studies. The super-paramagnetic-like slow relaxation of its magnetization was not observed for 2 in out-of-phase ac magnetic susceptibility due to the absence of a large enough energy barrier. Magnetization versus an applied dc field exhibited a hysteresis loop at 2 K with a coercivity of 1069.10 Oe and remanent magnetization of 0.374 μB in 1, while 2 has no coercivity in the hysteresis loop even at the lowest temperature (2.0 K), and no saturation was observed up to 7.0 T field supporting antiferromagnetic interactions present in the polymer. Hydroxymethyl ; Azide ; Crystallography ; Chemistry ; Coordination polymer ; Crystal engineering ; Polymer ; Tris ; Zigzag ; Propane ; Crystal structure ; Topology (electrical circuits) ; Polymer chemistry ; Stereochemistry ; Organic chemistry ; Supramolecular chemistry ; Mathematics Magnetism in coordination complexes ; Metal-Organic Frameworks: Synthesis and Applications ; Lanthanide and Transition Metal Complexes
Authors: Yuanyuan Zhang | Lefu Mei | Sergey M. Aksenov | Dina V. Deyneko | Haikun Liu | Dian Zhang | Zhaohui Huang
Source: Journal of the American Ceramic Society (article, 2019-12-07)
Field: Materials Science — Materials Chemistry

New apatite‐type phosphor Ca <sub>9</sub> La(PO <sub>4</sub> ) <sub>5</sub> (SiO <sub>4</sub> )F <sub>2</sub> :Tb <sup>3+</sup> ,Dy <sup>3+</sup> with improved color rendering index Abstract Ca 9 La(PO 4 ) 5 (SiO 4 )F 2 :Tb 3+ ,Dy 3+ (CLPSF:Tb 3+ ,Dy 3+ ) phosphors were successfully prepared using the traditional solid‐state technique. The crystal structure was refined and the luminescence properties have been examined in detail. The band gap and electronic structure of Ca 9 La(PO 4 ) 5 (SiO 4 )F 2 were performed by the periodic density functional theory (DFT) calculation. The spectral and fluorescence decay dynamics of CLPSF:Tb 3+ ,Dy 3+ show that the energy transfer behavior between Tb 3+ and Dy 3+ ions is observed. The CLPSF:Tb 3+ ,Dy 3+ phosphors can be efficiently excitable at the wavelengths range from 300 to 500 nm. The emission spectrum covers the whole visible part of the spectra with the sharp emission bands in red, green, and blue regions. The correlated color temperature (CCT) and color rendering index (CRI) of white light emission could be improved by the fine‐tuning of the Tb 3+ and Dy 3+ ions ration in accordance with the energy transfer behavior. Thus, the CLPSF:Tb 3+ ,Dy 3+ phosphor could be used as a material for the near‐ultraviolet ( n ‐UV) and white light‐emitting diodes ( w ‐LEDs). Phosphor ; Analytical Chemistry (journal) ; Luminescence ; Emission spectrum ; Ion ; Fluorescence ; Light-emitting diode ; Ultraviolet ; Materials science ; Color temperature ; Chemistry ; Spectral line ; Optoelectronics ; Optics ; Physics Luminescence Properties of Advanced Materials ; Crystal Structures and Properties ; Solid-state spectroscopy and crystallography
Authors: Shuai Che | Xin Fang | Siyang Li | Xudong Chen | Tao Du
Source: Zeitschrift für anorganische und allgemeine Chemie (article, 2019-12-05)
Field: Chemistry — Inorganic Chemistry

Modification of Potassium Chabazites Derived from Fly Ash by Dosing Extra Cations: Promoted CO<sub>2</sub> Adsorption Capacities and Fine‐Tuned Frameworks Potassium chabazite (K‐CHA), a typical microporous zeolite with excellent CO 2 separating properties, was synthesized with waste fly ash and modified via cation dosing treatments using cesium and zinc cations, respectively. The resulting CHAs were analyzed by XRF, XRD, FT‐IR, SEM, and N 2 physisorption, whose CO 2 adsorption properties were then tested on the reorganized TGA apparatus. It showed from XRF data that cesium and zinc cations were successfully imported in the original K‐CHA by cation dosing, but the CHA microstructures and morphologies of K‐CHA were perfectly retained as confirmed by XRD, FT‐IR, SEM and N 2 physisorption. Since there were still over 9 potassium cations per unit cell in cation dosed Cs‐CHA and Zn‐CHA, they both maintained the favored properties of K‐CHA as “molecular trapdoors”. In the following adsorption experiments, the CO 2 uptakes of Cs‐CHA and Zn‐CHA at 333 K and 1 bar, compared with K‐CHA, elevated from 1.70 mmol · g –1 to 2.34 and 2.03 mmol · g –1 , and the import of zinc cation also presented a positive effect on the adsorption kinetics. Detailed comparisons suggested modifications with cesium and zinc cations fine‐tune the CHA complying with different mechanisms, and CHAs modified via cation perform more approvingly than fully ion‐exchanged ones, providing us important insights into CHA modifications and applications in practice. Physisorption ; Chemistry ; Adsorption ; Microporous material ; Chabazite ; Potassium ; Zeolite ; Zinc ; Fly ash ; Nuclear chemistry ; Sodalite ; Inorganic chemistry ; Physical chemistry ; Organic chemistry ; Catalysis Zeolite Catalysis and Synthesis ; Metal-Organic Frameworks: Synthesis and Applications ; Covalent Organic Framework Applications
Authors: Lei Liu | Yanju Ji | Yifan Liu | Liqiang Liu
Source: Journal of Applied Mathematics and Physics (article, 2019-01-01)
Field: Materials Science — Materials Chemistry

First-Principle Studies on the Ga and As Doping of Germanane Monolayer The study of energetics, structural, the electronic and optical properties of Ga and As atoms substituted for doped germanane monolayers were studied by first-principles calculations based on density functional theory. Both of the two doping are thermodynamically stable. According to the band structure and partial density of the states, gallium is p-type doping. Impurity bands below the conduction band lead the absorption spectrum moves in the infrared direction. Arsenic doping has impurity level passing through the Fermi level and is n-type doping. The analysis of optical properties confirms the value of bandgap and doping properties. Doping ; Density functional theory ; Materials science ; Monolayer ; Gallium ; Condensed matter physics ; Fermi level ; Band gap ; Impurity ; Density of states ; Electronic band structure ; Electronic structure ; Infrared ; Nanotechnology ; Chemistry ; Optoelectronics ; Computational chemistry ; Physics ; Optics ; Quantum mechanics 2D Materials and Applications ; Graphene research and applications ; Topological Materials and Phenomena
Authors: Nóra V. May | G. Tamás Gál | Zsolt Szentendrei | L. Korecz | Zoltán May | María Grazia Ferlin | Annalisa Dean | Petra Bombicz | Valerio Di Marco
Source: New Journal of Chemistry (article, 2019-01-01)
Field: Chemistry — Inorganic Chemistry

Relationship between solid state structure and solution stability of copper(<scp>ii</scp>)–hydroxypyridinecarboxylate complexes More acidic –OH groups increase the solution stability of copper(<sc>ii</sc>)–hydroxypyridinecarboxylate complexes and they lose the bridging role in cyclic dimer formation. Chemistry ; Copper ; Solid-state ; Stability (learning theory) ; Crystallography ; Chemical engineering ; Physical chemistry ; Organic chemistry Metal-Organic Frameworks: Synthesis and Applications ; Metal complexes synthesis and properties ; Magnetism in coordination complexes