Search

The pyrolysis and combustion mechanism of the hydrocarbon fuel has important scientific and practical significance. However, it is difficult to detect the whole intermediates and products using traditional methods, which brings trouble to the analysis of the reaction process. In this paper, the microscopic reaction mechanism and the main products of n-eicosane (C20H42) were simulated based on the reactive force field molecular dynamics (ReaxFF-MD). The effects of temperature (2000–3500 K) and oxygen on the initial decomposition, the distribution of main products, and the reactive pathways of C20H42 fuel were studied to determine its reaction mechanism. The initial decomposition of C20H42 was mainly initiated by small alkyl radicals in pyrolysis, and by the oxygen-containing radicals in combustion. The participation of oxygen had a greater effect on accelerating the decomposition reaction. The reactions involving oxygen of C20H42 initial decomposition accounted for 87.5% of the total reactions at 2000 K. Moreover, the detailed distribution and formation pathways of the main products of H2, C2H4, CH4, H2O, CO, and CO2 were depicted to construct the overall reaction mechanism of C20H42. •H radical formed from the composition of C2H4 was exactly consistent with the •H radical consumed by the generation of CH4 and H2 in the pyrolysis stage. The feasibility of the simulation method was verified by the result of thermal analysis. The results are helpful for further research on the reaction mechanism of hydrocarbon fuels.

AIM To investigate the potential role of Kruppel-like factor 6 (KLF6) in the odontoblastic differentiation of immortalized dental papilla mesenchymal cells (iMDP-3) cells. METHODOLOGY Alizarin Red S (ARS) and Alkaline phosphatase (ALP) staining was used to examine the mineralization effect of iMDP-3 cells after odontoblastic induction. Real-time PCR and Western blotting were employed to analyse dentine sialophosphoprotein (DSPP), dentine matrix protein 1 (DMP1), RUNX family transcription factor 2 (RUNX2), ALP and KLF6 expression during this process. Co-expression of the KLF6 with DMP1, DSPP and RUNX2 was detected by double immunofluorescence staining to explore their local relationship in the cell. To further investigate KLF6 functions, Klf6 gain- and loss-of-function assays followed by ARS and ALP stainings, real-time PCR and Western blotting were performed using Klf6-overexpression plasmids and Klf6 siRNA to investigate whether changes in Klf6 expression affect the odontoblastic differentiation of iMDP-3 cells. Dual-luciferase reporter assays were used to elucidate the mechanistic regulation of Dspp and Dmp1 expression by Klf6. Means were compared using the unpaired t-test and Kruskal-Wallis one-way anova with P

Successful osseointegration involves the biological behavior of bone marrow stem cells (BMSCs) on an implant surface; however, the role of BMSC-derived extracellular vesicles (EVs)/exosomes in osseointegration is little known. This study aimed to: (i) explore the interaction force between exosomes (Exo) and cells on a titanium surface; (ii) discuss whether the morphology and biological behavior of BMSCs are affected by exosomes; and (iii) preliminarily investigate the mechanism by which exosomes regulate cells on Ti surface. Exosomes secreted by rat BMSCs were collected by ultracentrifugation and analyzed using transmission electron microscopy and nanoparticle tracking analysis. Confocal fluorescence microscopy, scanning electron microscopy, Cell Counting Kit-8 (CCK-8), quantitative real-time polymerase chain reaction techniques, and alkaline phosphatase bioactivity, Alizarin Red staining, and quantification were used to investigate the exosomes that adhere to the Ti plates under different treatments as well as the morphological change, adhesion, spread, and differentiation of BMSCs. We found that exosomes were efficiently internalized and could regulate cell morphology and promoted the adhesion, spreading, and osteogenic differentiation of BMSCs. These were achieved partly by activating the RhoA/ROCK signaling pathway. Our discovery presents a new insight into the positive regulatory effect of exosomes on the biological behaviors of BMSCs on Ti surface and provides a novel route to modify the surface of a Ti implant.

A series of seven isostructural homometallic dinuclear lanthanide metal complexes having the general formula [Ln2(L)2(NO3)4]·2CH3 OH, where L = 6-methoxy-2-(2-pyridylmethyliminomethyl) phenol Ln = Tb (1), Dy (2), Ho (3), Er (4), Tm (5), Yb (6), and Lu (7), are described. Compounds 1–7 were obtained from the reactions of Schiff base ligand (L) with the respective metal nitrates in the presence of triethylamine in MeOH. The structure of 2 was determined by single-crystal X-ray diffraction and the remaining compounds were characterized from X-ray powder diffraction patterns and found to be isostructural. The magnetic properties of 1–7 have been investigated using dc and ac susceptibility measurements. All these compounds show antiferromagnetic behavior between adjacent paramagnetic centers. Out of these seven compounds, only 2 displays an out-of-phase ac susceptibility signal which is attributed to the presence of the anisotropic DyIII ions.

Successful osseointegration in dental implants depends on balanced activation of osteoclasts and osteoblasts. Osteoporosis up-regulates osteoclast activity, so it is desirable to find effective interventions to inhibit osteoclastogenesis and enhance the osseointegration of implants under these conditions. It has been reported that the NF-κB essential modulator (NEMO)-binding domain (NBD) peptide can prevent osteoclast formation and bone resorption. In this study, we conjugated NBD peptide onto the surface of rough pure titanium (Ti) using the layer by layer technique. We analyzed the surface characteristics and determined the successful NBD integration by the presence of trivial granular structures, increased S elements and hydrophilia. Importantly, we first reported that Ti surface-conjugated NBD peptide retained its inhibitory effects on osteoclastogenesis by reducing osteoclast sealing zone formation and function. These effects were mediated by a reduction in NFATc1 expression, which in turn regulated integrin ανβ3 and MMP9 by targeting the P65 signaling pathway. In vivo TRAP staining suggested NBD-coating decreased osteoclast formation with less pseudopodia. Micro-CT and histomorphometric analysis demonstrated that NBD-coating enhanced pronounced osseointegration in vivo in ovariectomized rats. This study holds great promise for in vivo use of immobilized NBD peptide and offers an effective therapeutic approach to select more suitable Ti-implant surface modifications for improving implant osseointegration in osteoporotic patients.

Three isostructural lanthanide series with a core of MnMnLn2 are reported. These three families have the formulae of [MnMnLn2(μ4-O)2(H2edte)2(piv)6(NO3)2] {no crystallization solvent, Ln = La, Ce, Pr, Nd, Eu (1-4, 6); solv = 3MeCN, Ln = Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Y (5, 7-13)}, where H2edte = N,N,N',N'-tetrakis(2-hydroxyethyl)ethylenediamine and piv = pivalate; [MnMnLn2(μ4-O)2(H2edte)2(benz)6(NO3)2], where benz = benzoate, or [MnMnLn2(μ4-O)2(edteH2)2(benz)6(NO3)2]·2MeCN {Ln = Gd, Tb, Dy (14-16); and [MnMnLn2(μ4-O)2(edteH2)2(piv)8].solv {solv = 4MeCN, Ln = La (17); solv = 2MeCN·tol·H2O, Ln = Pr, Nd, Sm, Tb (18-20, 22); solv = 2MeCN·H2O, Ln = Gd (21). These compounds crystallize in two different systems, namely, monoclinic in the space groups P21/n for 1-4, 6, and 14-16 and C2/c for 5, 7-13, 18-20, and 22 and triclinic in the space group P1[combining macron] for 17 and 21. The crystal structures of these compounds display a face-fused dicubane structure connected by different types of bridged oxygen atoms. Solid-state dc magnetic susceptibility characterization was carried out for 1-22, and fitting showed that MnIIIMnIII is antiferromagnetically (AF) coupled and MnIIMnIII, MnIILn and MnIIILn are weakly ferromagnetically coupled. In addition, ac measurements were carried out and showed that only 7, 15, and 22 for Tb, 8 and 16 for Dy, and 20 for Sm exhibited slow magnetization relaxation. In the case of 15, it was possible to determine the energy barrier of the slow-relaxation behavior by fitting peak temperatures to the Arrhenius law, which gave a value of Ueff = 21.2 K and a pre-exponential factor of τ0 = 4.0 × 10-9 s.

Osteomyelitis, which is characterized by progressive inflammatory bone destruction and resorption, is a difficult‑to‑treat infection. Staphylococcus aureus (S. aureus) is one of the major causes of this disease. This pathogenic microorganism possesses several characteristics, which facilitate its involvement in the occurrence and progression of osteomyelitis. A cell‑permeable peptide inhibitor of the IκB kinase complex, the nuclear factor (NF)‑κB essential modulator‑binding domain (NBD) peptide, has been reported to block osteoclastogenesis and may be considered a potential strategy for preventing inflammatory bone resorption. However, it remains to be determined as to whether the NBD peptide can regulate inflammation and bone resorption in S. aureus‑induced osteomyelitis. In order to investigate the role of NBD in S. aureus‑induced osteomyelitis, the present study obtained the NBD peptide, and confirmed that it inhibited receptor activator of NF‑κB ligand‑induced osteoclastogenesis in vitro. Subsequently, a bone defect was generated and S. aureus was injected into the mandible of experimental animals, in order to establish an in vivo osteomyelitis model. The present study analyzed the following three experimental groups: Untreated, treated with debridement, and treated with debridement plus NBD peptide administration. The results revealed that treatment with the NBD peptide reduced the bone defect in a 3‑dimensional manner, and reduced bone resorption. To the best of our knowledge, the present study is the first to demonstrate that, in a model of osteomyelitis caused by S. aureus, the NBD peptide serves a role in inhibiting osteolysis and promoting bone remodeling in the direction of osteogenesis. The effects were better than those produced by debridement alone, thus suggesting that it may have promising therapeutic potential in osteomyelitis.

The paper presents a new material (named PMPP) with interpenetrating polymer network (IPN) formed by rigid polysilsesquioxane and flexible poly(hexamethylene diisocyanate)/poly(ethylene glycol) (PHMDI/PEG). Based on the network, polysilsesquioxanes with different structures, such as ladder-like polysilsesquioxane (PPSQ), cage-like polysilsesquioxane (T7POSS) and reactive ladder-like polysilsesquioxane (VPOSS), were selected to further modify PMPP. All samples were subjected to mechanical analysis, thermal analysis and combustion analysis and simulated by molecular dynamics (MD) and MesoDyn simulation. The introduction of polysilsesquioxanes obviously improved the flexural strength, tensile strength, heat resistance and fire resistance due to the strong interaction between polysilsesquioxanes and PMPP network structures. The results of solubility parameters (δ), radial distribution functions (RDF), Flory-Huggins parameters (χ) and mesoscopic morphologies showed that T7POSS and VPOSS had stronger interaction, better compatibility and dispersion in PMPP, thereby providing theoretical foundation for performance improvements.

A new mixed-valent Mn–Ln complex with an Mn 9 III Mn 2 II La2 core $$ [{\text{Mn}}_{9}^{\text{III}} {\text{Mn}}_{2}^{\text{II}} {\text{La}}_{ 2} (\mu_{ 4} {-}{\text{O}})_{7} (\mu_{ 3} {-}{\text{O}})(\mu_{ 3} {-}{\text{OH}})_{ 2} ({\text{benzoate}})_{ 1 8} ({\text{NO}}_{3} )({\text{MeCN}})] $$ has been synthesized. Its magnetic characterization reveals a complex with dominating slow relaxation. In addition, alternating current (ac) susceptibility measurements reveal a frequency-dependent out-of-phase (χ′′M) signal below 4 K, suggesting the complex to be a single-molecule magnet.

A 3D metal-organic framework (MOF) having single-molecule magnet (SMM) linkers was prepared in crystalline form by using a tetrairon(III) complex functionalised with two divergent pyridyl groups, namely [Fe4 (pPy)2 (dpm)6 ] (1; H3 pPy=2-(hydroxymethyl)-2-(pyridin-4-yl)propane-1,3-diol, Hdpm=dipivaloylmethane). Reaction of 1 with silver(I) perchlorate afforded {[Fe4 (pPy)2 (dpm)6 ]2 Ag}ClO4 (2), which crystallises in a cubic face-centred lattice and exhibits two interlocked diamondoid networks. In 2, the SMMs act as linear ditopic synthons, and silver(I) ions as tetrahedral nodes coordinated by four pyridyl nitrogen atoms. The magnetic properties of 1 (S=5 and D≈-0.4 cm(-1) in the ground spin state) are largely preserved in 2, which shows slow magnetic relaxation with an anisotropy barrier of Ueff /kB =11.46(10) K in zero field and 14.25(8) K in an applied field of 1 kOe. However, crystal symmetry triggers highly noncollinear magnetic anisotropy contributions oriented at 109.47° from each other along the threefold axes of AgN4 tetrahedra, a unique scenario fully confirmed by a single-crystal cantilever torque magnetometry investigation. Magnetisation curves down to 0.03 K demonstrated the occurrence of a wide hysteresis loop when the magnetic field was swept along one of the four Ag-N bonds. By symmetry, the crystalline compound can then be persistently magnetised parallel or antiparallel to the four main diagonals of the unit cell, although the crystals have no overall second-order anisotropy.

Preparation of polystyrene nanocomposites containing flame retardants is difficult to achieve in one step by suspension polymerization. Styrene suspension polymerization was studied to determine the effects of the flame retardant on the polymerization process and properties of polystyrene beads. Triphenyl phosphate (TPP) was used in this work, which can dissolve completely in styrene monomers. The results showed that TPP were nanosized spherical particles, distributed homogenously and uniformly in a polystyrene (PS) matrix, and the formation mechanism of TPP nanoparticles was also investigated. In addition, the effects of TPP on the styrene polymerization process were investigated. With TPP amount increasing, the polymerization time increased significantly; molecular weight of PS nanocomposites also decreased and molecular weight distribution became wide; the particle size distribution (PSD) of the PS nanocomposites became wider than pure PS slightly as the particle size decreased. PS/TPP nanocomposites obtained good flame retardance because of nanodispersed TPP particles in its matrix. In a word, the suspension polymerization method provides a facile approach to prepare PS/TPP nanocomposites with better properties.

The synthesis and characterization of a family of compounds (pipzH2)[CrIII2LnIII4(µ4-O)2(µ3-OH)4(H2O)10(µ3-SO4)4(SO4)2]·2H2O [hereafter abbreviated as Cr2Ln4; Ln = Tb (1), Ho (2), Er (3), Yb (4), and Y (5); pipz = piperazine] are reported. The compounds were obtained from hydrothermal reactions of Ln(NO3)3·6H2O (Ln = Tb, Ho, Er, Yb, and Y), Cr(NO3)3·9H2O, Na2SO4, and pipz in a 2:1:3:4 molar ratio. Single-crystal X-ray diffraction studies revealed that 1–5 crystallize isomorphously in the space group P21/c with Z = 2. The metallic core is composed of a rare face-fused double-cubane [CrIII2LnIII4(µ4-O2–)2(µ3-OH–)4]10+ unit. The temperature dependence of bulk magnetic susceptibilities is indicative of antiferromagnetic interactions dominant in the Tb, Ho, and Er compounds. In fitting with the data of the diamagnetic YIII analogue, the interactions of Cr–Cr in this system are determined to be ferromagnetic with a coupling strength of 3.61(11) cm–1, but the type of Cr–Ln could be antiferromagnetic. The dynamic magnetic properties revealed the presence of slow magnetic relaxation in the Tb and Er analogues, which represent two rare examples of CrIII-containing clusters that exhibit single-molecule magnet (SMM) behavior.

In-depth investigations of the low energy electronic structures of mononuclear lanthanide complexes, including single molecule magnets, are challenging at the best of times. For magnetically coupled polynuclear systems, the task seems well nigh impossible. However, without detailed understanding of the electronic structure, there is no hope of understanding their static and dynamic magnetic properties in detail. We have been interested in assessing which techniques are most appropriate for studying lanthanide single-molecule magnets. Here we present a wide ranging theoretical and experimental study of the archetypal polynuclear lanthanide single-molecule magnet Dy3 and derive the simplest model to describe the results from each experimental method, including high-frequency electron paramagnetic resonance and far-infrared spectroscopies and cantilever torque magnetometry. We conclude that a combination of these methods together with ab initio calculations is required to arrive at a full understanding of the properties of this complex, and potentially of other magnetically coupled lanthanide complexes. crosscheck: This document is CrossCheck deposited related_data: Supplementary Information identifier: Liviu Ungur (ORCID) identifier: Liviu Ungur (ResearcherID) copyright_licence: The Royal Society of Chemistry has an exclusive publication licence for this journal copyright_licence: This article is freely available. This article is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported Licence (CC BY-NC 3.0) history: Received 22 January 2016; Accepted 16 March 2016; Accepted Manuscript published 16 March 2016; Advance Article published 29 March 2016; Version of Record published 21 June 2016 ispartof: Chemical Science vol:7 issue:7 pages:4347-4354 ispartof: location:England status: published

TbPc2 single-molecule magnets adsorbed on a magnesium oxide tunnel barrier exhibit record magnetic remanence, record hysteresis opening, perfect out-of-plane alignment of the magnetic easy axes, and self-assembly into a well-ordered layer.

Herein we report the synthesis and characterization of a dinuclear TbIII single-molecule magnet (SMM) with two [TbPc2]0 units connected via a fused-phthalocyaninato ligand. The stable and robust complex [(obPc)Tb(Fused-Pc)Tb(obPc)] (1) was characterized by using synchrotron radiation measurements and other spectroscopic techniques (ESI-MS, FT-IR, UV). The magnetic couplings between the TbIII ions and the two π radicals present in 1 were explored by means of density functional theory (DFT). Direct and alternating current magnetic susceptibility measurements were conducted on magnetically diluted and nondiluted samples of 1, indicating this compound to be an SMM with improved properties compared to those of the well-known [TbPc2]−/0/+ and the axially symmetric dinuclear TbIII phthalocyaninato triple-decker complex (Tb2(obPc)3). Assuming that the probability of quantum tunneling of the magnetization (QTM) occurring in one TbPc2 unit is PQTM, the probability of QTM simultaneously occurring in 1 is PQTM2, mean...

A family of isostructural undecanuclear 3d–4f coordination clusters of formula [FeIII7LnIII4O4(OH)3(tea)2(Htea)3(Piv)7(H2O)2(NO3)3], where Ln = Y (1), Gd (2), Tb (3), Dy (4); PivH ≡ pivalic acid and H3tea ≡ triethanolamine, was synthesised. The central Fe7 core of the coordination cluster can be described in terms of two {Fe4O2} butterfly motifs sharing a common body Fe atom. The two Fe4 mean-planes subtend a dihedral angle of ca. 72°. The Tb (3) and Dy (4) compounds show Single Molecule Magnet (SMM) behaviour as confirmed by ac-susceptibility and μ-SQUID measurements. Furthermore, 57Fe Mossbauer spectra of 1–4 confirm the presence of high-spin FeIII sites. The spectra of all complexes in the high temperature range (30–300 K) show broad overlapping doublets which were assigned to the body and wing-tip pairs of metal ions within the Fe7 core. The low temperature Mossbauer spectra show dependence on the nature of the rare-earth metal as a result of its interaction with the iron sites. Thus, we observed a transition from fast (2), to intermediate (1) and very slow (frozen) (3, 4) spin fluctuation phenomena in these compounds.

Two new heterometallic Zn3 Ln3 (Ln3+ =Dy, Tb) complexes, with a double triangular topology of the metal ions, have been assembled from the polytopic Mannich base ligand 6,6'-{[2-(dimethylamino)ethylazanediyl]bis(methylene)}bis(2-methoxy-4-methylphenol) (H2 L) with the aid of an in situ generated carbonate ligand from atmospheric CO2 fixation. Theoretical calculations indicate axial ground states for the Ln3+ ions in these complexes, with their local magnetic moments being almost coplanar and tangential to the Ln3+ atoms that define the equilateral triangle. Therefore, they can be considered as single-molecule toroics (SMTs) with almost zero total magnetic moment. Micro-SQUID measurements on the Dy3+ counterpart show hysteresis loops below 3 K that have an S-shape, with large coercive fields opening upon cooling. This behavior is typical of a single molecule magnet (SMM) with very slow zero-field relaxation. At around ±0.35 T, the loops have a broad step, which is due to a direct relaxation process and corresponds to an acceleration of the relaxation of the magnetization, also observed at this magnetic field from ac susceptibility measurements. Simulations suggest that the broad step corresponds to two level avoidance of crossing points where the spin chiral Kramers doublet meets excited states of the coupled manifold, whose position is defined by exchange and dipole interactions. The Tb3+ counterpart does not exhibit SMM behavior, which is due to the fact that the degeneracy of the ground state of the exchange coupled system is lifted at zero field, thus favoring quantum tunneling of magnetization (QTM).

A new synthetic non-halogen, flame-retardant cyclotriphosphazene containing the silicon functional group (APESP) was incorporated with ammonium polyphosphate (APP) to prepare flame-retarded polypropylene (PP). APESP/APP/PP composites were prepared by melt-blending and extrusion in a twin-screw extruder with different loading levels of APESP. The combustion and thermal behaviors were investigated based on the limiting oxygen index, UL-94, and cone calorimeter test as well as thermogravimetric analysis (TGA). Then, TGA coupled with Fourier transform infrared spectroscopy was used to probe the degradation mechanism of APESP/APP/PP composites. The results indicated that a good flame-retardant performance could be achieved by incorporating APESP with APP in PP. The synergistic effect between APESP and APP was observed and is discussed here. The mechanical properties and rheological behaviors of APESP/APP/PP composites indicated that APESP significantly contributed to the dispersion and distribution of APP in t...

A disk-shaped [Fe(III) 7 (Cl)(MeOH)6 (μ3 -O)3 (μ-OMe)6 (PhCO2 )6 ]Cl2 complex with C3 symmetry has been synthesised and characterised. The central tetrahedral Fe(III) is 0.733 Å above the almost co-planar Fe(III) 6 wheel, to which it is connected through three μ3 -oxide bridges. For this iron-oxo core, the magnetic susceptibility analysis proposed a Heisenberg-Dirac-van Vleck (HDvV) mechanism that leads to an intermediate spin ground state of S=7/2 or 9/2. Within either of these ground state manifolds it is reasonable to expect spin frustration effects. The (57) Fe Mössbauer (MS) analysis verifies that the central Fe(III) ion easily aligns its magnetic moment antiparallel to the externally applied field direction, whereas the other six peripheral Fe(III) ions keep their moments almost perpendicular to the field at stronger fields. This unusual canted spin structure reflects spin frustration. The small linewidths in the magnetic Mössbauer spectra of polycrystalline samples clearly suggest an isotropic exchange mechanism for realisation of this peculiar spin topology.

The influence of solutions on ammonium dinitramide (ADN) crystal morphology was investigated using a combined experimental and molecular dynamics simulation approach. Scanning electron microscopy showed that ADN recrystallized from acetone, propanol, dimethyl sulfoxide (DMSO), and ethanol exhibited a lamellar structure, in contrast to the polyhedron structure obtained with isopropanol/NaF. X-ray diffraction analysis revealed that ADN crystals are mainly composed of six crystal faces (010, 011, 110, 100, 121, 031), and acetone, propanol, DMSO, and ethanol result in crystals in which growth at face (100) dominated. Molecular dynamics simulations indicated that the accessible surfaces and lattice energy (E latt) vary with the crystal faces. The interaction energy between solutions and crystal faces (E int) was dependent on both crystal faces and solution components, as was the attachment energy (E att). The relative standard deviation R dev ′ of the growth rate of the crystal faces was ordered as follows: acetone (0.117) > propanol (0.098) > DMSO (0.094) > ethanol (0.087) > isopropanol (0.078) > isopropanol/NaF (0.073). A larger R dev ′ resulted in a lamellar structure, while a smaller R dev ′ gave more homogeneous growth rates that resulted in polyhedron crystals.

Ethylene oxide–tetrahydrofuran copolyether (P(E-co-T)) crosslinked with isocyanate Desmodur (N100) is widely used as the binder system in solid energetic propellant. The effect of its cross-linking degree on the physical properties is important for the evaluation of the propellant binders. In this work, an efficient method was presented for simulating the cross-linking process, predicting the microscopic behaviors and macroperformances of cross-linked P(E-co-T)–N100 binder systems. During the simulation of cross-linking network forming, the initial physical mixture model of P(E-co-T)/N100 was firstly constructed and optimized through molecular dynamics. Then the possible cross-linking topology was generated by means of the identification of the reactive site pairs. In this way, the P(E-co-T)–N100 cross-linking pathway was realized by alternate structure optimization and junction reaction. The cross-linking intermediate models were analyzed, and the density and mechanical property profiles have revealed th...

Reactions of the N-substituted diethanolamine ligand N-n-butyldiethanolamine with chromium(II) and lanthanide(III)/rare earth salts (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y) in the presence of coligands give access to three series of isostructural 1:1 3d(Cr(III))/4f(Ln(III)) coordination cluster compounds that can be designated in terms of octanuclear "square-in-square" (Ln = La-Tb), hexanuclear "triangle-in-triangle" (Ln = Dy, Ho, Y) and tetranuclear "butterfly" or defect dicubane core (Ln = Er-Lu) topologies as revealed by single-crystal X-ray crystallographic analysis. The bulk magnetic properties were also measured. The influences of the various components in the reaction system on the final topology and the role of the ionic radius are discussed.

A new family of pentadecanuclear coordination cluster compounds (from now on simply referred to as clusters) [{Ln15 (OH)20 (PepCO2 )10 (DBM)10 Cl}Cl4 ] (PepCO2 =2-[{3-(((tert-butoxycarbonyl)amino)methyl)benzyl}amino]acetate, DBM=dibenzoylmethanide) with Ln=Y and Dy was obtained by using the cell-penetrating peptoid (CPPo) monomer PepCO2 H and dibenzoylmethane (DBMH) as supporting ligands. The combination of an inorganic cluster core with an organic cell-penetrating peptoid in the coordination sphere resulted in a core component {Ln15 (μ3 -OH)20 Cl}(24+) (Ln=Y, Dy), which consists of five vertex-sharing heterocubane {Ln4 (μ3 -OH)4 }(8+) units that assemble to give a pentagonal cyclic structure with one Cl atom located in the middle of the pentagon. The solid-state structures of both clusters were established by single-crystal X-ray crystallography. MS (ESI) experiments suggest that the cluster core is robust and maintained in solution. Pulsed gradient spin echo (PGSE) NMR diffusion measurements were carried out on the diamagnetic yttrium compound and confirmed the stability of the cluster in its dicationic form [{Y15 (μ3 -OH)20 (PepCO2 )10 (DBM)10 Cl}Cl2 ](2+) . The investigation of both static (dc) and dynamic (ac) magnetic properties in the dysprosium cluster revealed a slow relaxation of magnetization, indicative of single-molecule magnet (SMM) behavior below 8 K. Furthermore, the χT product as a function of temperature for the dysprosium cluster gave evidence that this is a ferromagnetically coupled compound below 11 K.

We synthesized heterometallic Gd-Pt complexes ([Gd2Pt3(H2O)2(SAc)12] (1) (SAc = thioacetate), [Y1.4Gd0.6Pt3(H2O)2(SAc)12] (3), [La2Pt3(H2O)2(SAc)12] (4) and [Gd2Pt3(H2O)6(SAc)12]·7(H2O) (5). Crystal structure and DFT calculation indicated a Gd***Pt heretometallic bond. Single-crystal ESR spectra determined the direction of magnetic anisotropy as direction of the Gd***Pt bond. In other word, Gd***Pt bond lead the direction of magnetic anisotropy. The hetero metallic Gd-Pt bond lower the symmetry of the Gd ion, splitting the Kramers doublet in a dc field. Thus, we observed clear field induced slow magnetic relaxation of 3 up to 36 K. We determined the relaxation process to be a direct process.

We report three dinuclear cobalt(II) complexes, [Co(L)Cl2]2 (L = bpy, mbpy, and dmpbt), that are bridged solely by chloride ions. High-field electron paramagnetic resonance and magnetometric measurements were applied to investigate the magnetic intramolecular Co–Co interactions. Simulation results based on the multispin model reveal that the complexes are weakly ferromagnetically coupled and that the isotropic exchange coupling constants differ slightly for the three complexes. Moreover, the competing effects of zero-field splitting and magnetic coupling on the temperature-dependent magnetic susceptibility were analyzed.

K3Fe(CN)6 reacts with the viologen 1,1′-bis(2,4-dinitrophenyl)-4,4′-bipyridinium dication, (DNP)2+, to form a supramolecular complex, (DNP)3[Fe(CN)6]2·10H2O (1). The crystal structure of 1 reveals that there are two [Fe(CN)6]3– anions within an organic framework of three (DNP)2+ cations with the shortest Fe(III)···Fe(III) distances of ca. 9.8 Å, distances that minimize extensive long-range magnetic exchange coupling interactions between the [Fe(CN)6]3– anions, and, thus, 1 is paramagnetic above ca. 17 K and exhibits weak ferromagnetic coupling between 17 and 3 K and antiferromagnetic coupling between 3 and 1.8 K. The long Fe(III)···Fe(III) distances permit slow spin–spin and slow spin–lattice paramagnetic relaxation, relative to the iron-57 Larmor precession frequency, as is evidenced by the Mössbauer spectra measured between 3 and 60 K; between 85 and 295 K, rapid paramagnetic relaxation is observed. Both the slow spin–spin and slow spin–lattice relaxation are mediated by the organic, π-conjugated viologen cations. The Fe–C distances, the Mössbauer isomer shifts, the temperature dependence of the magnetic susceptibility, and the 3 K magnetization results all indicate the presence of low-spin Fe(III) ions in the [Fe(CN)6]3– anions in 1. There is no unequivocal indication of the presence of any formal electron delocalization or transfer from the [Fe(CN)6]3– anion to the (DNP)2+ cations in the results obtained from X-ray crystallography, magnetic measurements, and Mössbauer spectra. Because of enhancement of the spin–orbit coupling by the heavy-atom or -ion effect, the Fe(III) ions in the [Fe(CN)6]3– anions interact with the (DNP)2+ cations, causing them to fluoresce with increasing intensity upon cooling from 90 to 25 K when excited at 300 nm. The resulting luminescence of the viologen (DNP)2+ cation induced by the [Fe(CN)6]3– anions indicates the presence of significant mixing of the molecular orbitals derived from the [Fe(CN)6]3– anions and the molecular orbitals associated with the (DNP)2+ cations to yield bonding supramolecular orbitals in 1, a mixing that is also observed between 50 and 3 K in the temperature dependence of the isomer shift of 1.

Two analogous tetranuclear lanthanide complexes have been synthesized with the general formula [Ln4(vht)4(MeOH)8](NO3)4·aMeOH·bH2O, where H2vht = (3,6-bis(vanillidenehydrazinyl)-1,2,4,5-tetrazine) and Ln = DyIII (1), GdIII (2). These complexes are characterized by several techniques; including single-crystal X-ray diffraction, SQUID magnetometry and single-crystal micro-SQUID hysteresis loop measurements. Elucidation of the crystal structure of the complexes shows that the lanthanide ions are bridged by a tetrazine ring, a rare bridging moiety for lanthanide ions. Magnetic studies reveal that both 1 and 2 exhibit weak ferromagnetic exchange interactions between Ln ions, and 1 displaying Single-Molecule Magnet (SMM) behaviour with a magnetisation reversal barrier of Ueff = 158 K (τ0 = 1.06 × 10−7 s).

Carbamate formation in green-plants through the RuBisCO enzyme continuously plays a pivotal role in the conversion of CO2 from the atmosphere into biomass. With this in mind, carbamate formation from CO2 by a lanthanide source in the presence of a secondary amine is herein explored leading to a lanthanide–carbamate cage with the formula [Dy4(O2CNiPr2)12]. Magnetic studies show slow relaxation leading to the observation of hysteresis loops; the tetranuclear cage being a single molecule magnet. Detailed interpretation of the data reveals: (i) the presence of two different exchange interactions, ferromagnetic and antiferromagnetic and (ii) the observation of exchange-bias quantum tunnelling with two distinct sets of loops, attributable to ferromagnetic interactions between dysprosium ions at longer distances and antiferromagnetic exchange between dysprosium ions at shorter distances. The results clearly demonstrate that the [Dy4(O2CNiPr2)12] cage acts as a quantum magnet which in turn could be at the heart of hybrid spintronic devices after having implemented CO2 as a feedstock.

A series of 2,6-bis(hydroxymethyl)-4-R-phenol ligands (H3LR; R = H, F, Cl, Br, I, Ph, NH2, NO2, SMe) have either been newly synthesized or the existing syntheses have been significantly improved to investigate ligand-functionalized analogues of the previously published coordination cluster [MnIII12MnII7(μ4-O)8(μ3-N3)8(HLMe)12(MeCN)6]Cl2·10MeOH·MeCN (1) with S = 83/2. The crystal structures and magnetic properties of three such Mn19 clusters, namely, [MnIII12MnII7(μ4-O)8(HLH)12(μ3-Cl)7(μ3-OMe)(MeOH)6]Cl2·16H2O·10MeOH·MeCN (3), [MnIII12MnII7(μ4-O)8(HLI)12(μ3-N3)8(MeOH)6](O2CH)2·16MeOH·10MeCN (4) and [MnIII12MnII7(μ4-O)8(μ3-Cl)7.7(μ3-OMe)0.3(HLSMe)12(MeOH)6]Cl2·27MeOH (5) are reported and compared to those of the parent cluster. When these ligands are functionalized with substituents of moderate electronegativity, it is possible to synthesize Mn19 analogues; however, when such ligands bear highly electron-donating (amino) or -withdrawing (nitro) substituents, the Mn19 analogues are no longer accessible. The Mn19 cluster framework is both magnetically and structurally robust with respect to the electron-donor/acceptor characteristics of the ligand substituent; therefore, the Mn19 system is an excellent platform for peripheral chemical engineering.

The dinuclear doubly azole-bridged copper(II) complexes [Cu(II)2(L)2(MeCN)4](ClO4)4·3.73MeCN·0.80H2O and [Cu(II)2(L)6](ClO4)4·solvent (solvent = 2MeCN·H2O; 2MeCN·2H2O; 1.5MeOH·3.5H2O) were prepared [L = 3-(6-methyl-2-pyridyl)-[1,2,4]triazolo[4,3-a]pyridine]. Structural characterizations revealed very different local geometries about the copper(II) ions, being trigonal bipyramidal for the former (τ = 0.76) and square pyramidal for the latter (τ = 0.07, 0.15, 0.07) complex. Magnetic measurements of bulk material [Cu(II)2(L)2(H2O)4](ClO4)4 and [Cu(II)2(L)6](ClO4)4·2H2O revealed antiferromagnetic coupling in both complexes, however, of very different strengths. Electron paramagnetic resonance (EPR) spectroscopy was applied to investigate magnetic properties of the complexes in detail. These experimental findings were supported by broken-symmetry DFT calculations. Systematic magneto-structural correlations are discussed.

Alternating current magnetic investigations on the trigonal-planar high-spin Co(2+) complexes [Li(15-crown-5)] [Co{N(SiMe3)2}3], [Co{N(SiMe3)2}2(THF)] (THF = tetrahydrofuran), and [Co{N(SiMe3)2}2(PCy3)] (Cy = -C6H13 = cyclohexyl) reveal that all three complexes display slow magnetic relaxation at temperatures below 8 K under applied dc (direct current) fields. The parameters characteristic for their respective relaxation processes such as effective energy barriers Ueff (16.1(2), 17.1(3), and 19.1(7) cm(-1)) and relaxation times τ0 (3.5(3) × 10(-7), 9.3(8) × 10(-8), and 3.0(8) × 10(-7) s) are almost the same, despite distinct differences in the ligand properties. In contrast, the isostructural high-spin Fe(2+) complexes [Li(15-crown-5)] [Fe{N(SiMe3)2}3] and [Fe{N(SiMe3)2}2(THF)] do not show slow relaxation of the magnetization under similar conditions, whereas the phosphine complex [Fe{N(SiMe3)2}2(PCy3)] does, as recently reported by Lin et al. (Lin, P.-H.; Smythe, N. C.; Gorelsky, S. I.; Maguire, S.; Henson, N. J.; Korobkov, I.; Scott, B. L.; Gordon, J. C.; Baker, R. T.; Murugesu, M. J. Am. Chem. Soc. 2011, 135, 15806.) Distinctly differing axial anisotropy D parameters were obtained from fits of the dc magnetic data for both sets of complexes. According to density functional theory (DFT) calculations, all complexes possess spatially nondegenerate ground states. Thus distinct spin-orbit coupling effects, as a main source of magnetic anisotropy, can only be generated by mixing with excited states. This is in line with significant contributions of excited determinants for some of the compounds in complete active space self-consistent field (CASSCF) calculations done for model complexes. Furthermore, the calculated energetic sequence of d orbitals for the cobalt compounds as well as for [Fe{N(SiMe3)2}2(PCy3)] differs significantly from the prediction by crystal field theory. Experimental and calculated (time-dependent DFT) optical spectra display characteristic d-d transitions in the visible to near-infrared region. Energies for lowest transitions range from 0.19 to 0.35 eV; whereas, for [Li(15-crown-5)][Fe{N(SiMe3)2}3] a higher value is found (0.66 eV). Zero-field (57)Fe Mößbauer spectra of the three high-spin iron complexes exhibit a doublet at 3 K with small and similar values of the isomer shifts (δ), ranging between 0.57 and 0.59 mm/s, as well as an unusual small quadrupole splitting (ΔEQ = 0.60 mm/s) in [Li(15-crown-5)][Fe{N(SiMe3)2}3].

The versatile verdazyl family provides a new member as its reduced form 1,5-dimethyl-3-[3′-(hydroxymethyl)-2′-pyridine]-6-oxotetrazane (H3vdpyCH2OH). Upon oxidation and deprotonation in the presence of the acetate salts of CoII and DyIII, the vdpyCH2OH radical is able to self-assemble [(vdpyCH2O)2Co2Dy2ac8] (Hac = HO2CCH3), a 2p–3d–4f cluster displaying single-molecule-magnet properties.

The compatibilization of cyclotriphosphazene N3P3[NH(CH2)3Si(OCH2CH3)3]6 (APESP) in flame retarded polypropylene (PP)/ammonium polyphosphate (APP) composites was investigated by atomistic and mesoscale simulations. Molecular dynamics (MD) and dissipative particle dynamics (DPD) simulation method were used to study the binding energy (Ebinding), radius distribution function, hydrogen bond, Flory–Huggins parameter (χ) and mesoscopic morphology of the composites. It was found that the compatibility of APP in PP matrix significantly got better due to the loading of the cyclotriphosphazene derivative APESP, compared with the loading of γ-aminopropyltriethoxysilane (APES) or hexachlorocyclotriphosphazene. The Ebinding value of APP and PP increased to 161.45 kJ/mol in PP/APP/APESP, in contrast to 2.82 kJ/mol in PP/APP. Furthermore, the last frame of MD profiles indicated the presence of strong hydrogen bond between APP and APESP molecules. The DPD data showed that APESP made the dispersion and distribution of APP in PP matrix more homogeneous because of improved interfacial interaction. To verify the simulation results, the PP/APP, PP/APP/APES and PP/APP/APESP composites were prepared to analyze mechanical properties, morphologies and flame retardancy. Elongation at break of PP/APESP/APP was 334.79%, nearly four times as much as that of PP/APP. Scanning Electron Microscope (SEM) microphotographs indicated that the dispersion of APP in PP matrix was improved because of the loading of APESP. At the same time, LOI value of the composites with APESP levelled up from 21.7% to 26.5%, and UL 94 rating reached to V-2. The above experimental data demonstrated that the simulation strategy in this investigation is an effective path for molecular design and performance prediction of the flame retarded systems.

The reaction of Co(NO3)2·6H2O with N,N-diethanolamine (H2L1) in the presence of sodium acetate, using triethylamine as a base, leads to a tridecanuclear mixed-valent cobalt cluster [CoII9CoIII4(OH)6(H2O)2(L1)8(OAc)4](NO3)4·24H2O (1). Similar reaction with a newly designed hydroxy- and nitrogen-rich chelating ligand 2-[bis(pyridin-2-ylmethyl)amino]-2-(hydroxymethyl)propane-1,3-diol (H2L2) gives a mixed-valent Co13 cluster [CoII7CoIII6(OH)12(L2)6](NO3)8·10H2O (2). The cobalt ions in both 1 and 2 are nearly coplanar, forming a novel shieldlike configuration for 1 and a unique hexagram structure for 2, both of which have not been observed for the polynuclear cobalt clusters. The magnetic susceptibility investigation showed that complexes 1 and 2 exhibited ferromagnetic coupling between CoII ions. Further magnetic studies revealed a slight frequency dependence of 2, which suggests that 2 might be a single-molecule magnet.

The two Ni(2+)-containing heteropolytungstates [Ni14(OH)6(H2O)10(HPO4)4(P2W15O56)4](34-) (Ni14) and [Ni5(OH)4(H2O)4(β-GeW9O34)(β-GeW8O30(OH))](13-) (Ni5) have been successfully synthesized in aqueous, basic media under conventional reaction conditions, and they were characterized by single-crystal X-ray diffraction, IR spectroscopy, thermogravimetric and elemental analyses, electrochemistry, and magnetic studies. The cyclic voltammetry (CV) patterns of Ni14 and Ni5 showed chemically reversible multielectronic waves for slow scan time scales. For Ni14, an important acidity inversion effect between its reduced forms was observed. Magnetic studies revealed dominant ferromagnetic interactions among the nickel(II) ions in both polyanions.

Di-, tetra- and hexanuclear metallacycles of Zn2+, Co2+, and Ni2+ prepared by ring-opening reactions of 1,8-naphthalic anhydride with corresponding metal acetate in the presence of 2,2′-bipyridine or 1,10-phenanthroline, namely [Co4(bpy)4(naphDA)4(H2O)4]·12H2O (I), [Co6(phn)6(naphDA)6(H2O)12]·20H2O (II), [Ni6(phn)6(naphDA)6(H2O)12]·20H2O (III), [Zn4(bpy)4(naphDA)4(H2O)4]·2H2O (IV), and [Zn2(phn)2(naphDA)2(H2O)2]·H2O (V) (H2naphDA = 1,8-naphthalene dicarboxylic acid, bpy = 2,2′-bipyridine, phn = 1,10-phenanthroline) were structurally characterized. In the case of the reaction of nickel(II) acetate with 1,8-naphthalic anhydride in the presence of bpy a mononuclear complex [Ni(bpy)(naphDA)(H2O)3]·H2O (VI) was observed. Both the Co2+-metallacycles on heating to 420 °C resulted in the formation of CoO. The magnetic properties of the metallacycles containing Co2+ and Ni2+ ions were investigated. Dominant antiferromagnetic interactions in the tetra- and hexanuclear Co2+-metallacycles were observed. The hexanuclear Ni2+-metallacycle III with a spin state S = 3 showed intramolecular ferromagnetic interactions. For the metallacycle III, the magnetic susceptibility data above 50 K could be reproduced with the parameters of g = 2.26 and JNi–Ni = +1.2 cm–1 using single J-model based on Hamiltonian H = –2J (S1·S2 + S2·S3 + S3·S4 + S4·S5 + S5·S6 + S6·S1).

Mixed-valence trinuclear manganese compounds [Mn3O(O2CTh)6(L)x(H2O)y]·n(solvent) (Th = thiophene, 1·CH3CN: L = pyridine (py), x = 3, y = 0, n = 1, solvent = CH3CN; 1·∼H2O: L = py, x = 3, y = 0, n = ∼1, solvent = H2O; 2: L = py, x = 2, y = 1, n = 0.25, solvent = CH3CN; 3: L = 3-Mepy, x = 2, y = 1, n = 0) containing a [MnIIMn2III(μ3-O)]6+ core have been prepared. Homo-valence tetranuclear manganese complexes (NBun4)[Mn4O2(O2CAr)9(L)] (4·ThCO2H·CH2Cl2: Ar = –Th, L = EtOH; 6: Ar = –Ph, L = H2O; 7: Ar = –Ph-p-Me, L = H2O; 8·CH2Cl2: –Ph-3,5-Me2, no L) with a [MnIII4(μ3-O)2]8+ core and [MnIIMnIII3O2(O2CTh)7(bpy)2] (5) were synthesized, structurally and magnetically characterized. Compounds 1–3 were obtained by comproportionation of MnII(O2CMe)2·4H2O with (NBun4)MnVIIO4 in aprotic pyridine (1) or aprotic/protic py/EtOH (2) or Mepy/EtOH (3) solvent mixtures. Clusters 4–8 were synthesized by comproportionation of MnII(O2CAr)2·xH2O/ArCOOH with (NBun4)MnVIIO4 in EtOH/CH3CN. X-ray structural characterization of the 2-thiophenecarboxylate (ThCO2−) containing compounds 1·CH3CN, 1·∼2H2O and 4·ThCO2H·CH2Cl2 revealed a thiophene ring disorder about the (O2)C–C(Th) bond so that the S atom and opposite (5–)CH group are distributed over two ring positions each. The MnII atom in the approximately isosceles triangular [MnIIMn2III(μ3-O)]6+ cores in 1 could be clearly assigned from bond valence sum calculations and bond distances. The [Mn4(μ3-O)2]8+ core in the anionic complexes in the structures of 4·ThCO2H·CH2Cl2 and 8·CH2Cl2 has an all MnIII oxidation level and “butterfly-like” arrangement. The magnetic properties of 4–8 were investigated by variable temperature magnetic susceptibility and magnetization measurements. Similar magnetic behavior was observed for the [MnIII4(μ3-O)2]8+ butterfly-core compounds 4, 6–8, with antiferromagnetic interactions between pairs of manganese ions with amplitude of ∼14.5 cm−1 and ∼4.6 cm−1 for the Mnb⋯Mnb and Mnb⋯Mnw coupling, respectively (b = body, w = wing). Changing the Ar-ligand size in [Mn4O2(O2CAr)9(L)]− does not have a significant effect on the magnetic properties of these butterfly clusters.

International audience; Two new complexes belonging to the family [Fe(II)(L)2(NCX)2] have been synthesized and structurally characterized. Complexation of the ligand L(O) = 2,5-di(2-pyridyl)-1,3,4-oxadiazole results in the formation of two derivatives of [Fe(II)(L(O))2(NCS)2] (1) with the common s-trans and the rarely observed s-cis conformation. No thermal spin crossover (SCO) was observed for the amorphous bulk material of the mixture. Using the new ligand L(Se) = 2,5-di(2-pyridyl)-1,3,4-selenadiazole, compound [Fe(II)(L(Se))2(NCS)2]*1.4DCM*0.6MeOH (2*1.4DCM*0.6MeOH) was structurally characterized by single crystal X-ray diffraction. Bulk material of [Fe(II)(L(Se))2(NCS)2]*MeOH (2*MeOH) exhibits a thermally induced SCO with small hysteresis [T1/2(↓) = 91 K, T1/2(↑) = 96 K]. LIESST and reflectivity studies have been performed on the SCO complexes [Fe(II)(L(S))2(NCS)2], [Fe(II)(L(S))2(NCSe)2], [Fe(II)(L(S))2(NCBH3)2]*H2O [L(S) = 2,5-di(2-pyridyl)-1,3,4-thiadiazole], and 2*MeOH. All complexes belong to the T0 = 90 K line [T(LIESST) = T0 - 0.3T1/2]. [Fe(II)(L(S))2(NCS)2], that exhibits a two-stepped thermal SCO process, has been found to also exhibit two well-separated T(LIESST) temperatures [T(LIESST, 1) = 44 K; T(LIESST, 2) = 53 K].

Reaction of [MnIII8MnIV4O12(CH3COO)16(H2O)4] with [A-α-PW9O34]9− in a 1:2 molar ratio in aqueous, acidic medium resulted in the manganese(III)-containing, sandwich-type tungstophosphate [MnIII3(H2O)5(A-α-PW9O34)2]9− (1). Polyanion 1 crystallizes as a mixed potassium/cesium/guanidinium salt in the triclinic space group P 1 ¯ , with cell parameters a = 13.1718(19) A, b = 16.505(2) A, c = 22.842(4) A, α = 104.141(7)°, β = 106.267(8)°, γ = 101.369(6)°, V = 4430.6(12) A3, and Z = 2. The title polyanion comprises two [A-α-PW9O34]9− Keggin fragments linked via three MnIII ions, two of which are 6-coordinated and one is 5-coordinated. Polyanion 1 was further characterized by IR, TGA, elemental analysis, magnetic measurements, and electrochemistry.

The coordination behaviour of the new ligand 3-(2-pyrazyl)-[1,2,4]triazolo[4,3-a]pyridine (L2) has been studied. In the course of this investigation 12 complexes have been structurally characterised by single crystal X-ray diffraction, namely the discrete mononuclear complexes [FeII(L2)3](ClO4)2·1.25MeCN·1.25H2O (1·1.25MeCN·1.25H2O) and [FeII(L2)3](BF4)2·2MeCN·0.5H2O (2·2MeCN·0.5H2O), the 2D polymeric complex [CuII(L2)2](ClO4)2 (3), the 1D chain compounds [FeII2(L2)2(H2O)6(MeSO3)2](MeSO3)2 (6), [CoII(L2)2Cl2] (7a), [FeII(L2)2Cl2] (9) and [FeII(L2)2(NCS)2]·MeCN (13·MeCN) as well as the hydrogen-bonded and π–π-stacked mononuclear complexes [FeII(L2-κNpz4)2(NCS)2(MeOH)2] (10a), [FeII(L2-κNtp1)2(NCS)2(MeOH)2] (10b), [FeII(L2-κNpz4)2(NCSe)2(MeOH)2] (11), [FeII(L2-κNpz4)2(NCBH3)2(MeOH)2] (12a) and [FeII(L2-κNtp1)2(NCBH3)2(MeOH)2] (12b). The structural characterisation revealed a multitude of coordination modes for L2, which has been found to utilise all of its four potential donor atoms. Thus L2, acts as a unidentate ligand coordinating via Ntp1 or Npz4, as a bidentate Npz1,Ntp2-chelating ligand, as a bidentate Ntp1,Npz4-bridging ligand or as a terdentate ligand coordinating via Npz1,Ntp2,Npz4. Coordination isomerism has been observed in complexes 10 and 12.

The structural aspects and magnetic properties of a novel five-coordinated copper(II) coordination polymer derived from a carboxylate tethered naphthalimide ligand, namely 5-(1,3-dioxo-1H, 3H-benzo[de]isoquinolin-2-yl)-isophthalic acid are presented. The coordination polymer having monodentate carboxylate groups connecting the copper ions to form a spiral duplex structure shows anti-ferromagnetic property.

By heating of FeCl2 and MnCl2 in the ionic liquid [BMIm][OTf] (BMIm: 1-butyl-3- methylimidazolium, OTf: trifluoromethanesulfonate), the compounds [BMIm][M(OTf)3] (M: Fe+II, Mn+II) have been obtained as colorless crystals. Similarly, [BMIm][Li(OTf)2] was synthesized by heating of LiCl in [BMIm][OTf]. While the crystal quality of the [BMIm][M(OTf)3] (M: Fe+II, Mn+II) products thus obtained is low, mild oxidation of Fe(CO)5 or Mn2(CO)10 with GeI4 applied as an alternative in the same ionic liquid allowed a slow growth of well-formed, needle-shaped crystals. According to X-ray structure analysis based on single crystals, [BMIm][M(OTf)3] (M: Fe+II, Mn+II) crystals are monoclinic, and [BMIm][Li(OTf)2] crystals are triclinic. All compounds form infinite 1 ∞[M(OTf)3] (M=Fe, Mn) and 1 ∞[Li(OTf)2] chains. The compounds have further been characterized by FT-IR spectroscopy, energy-dispersive X-ray analysis (EDX), differential thermal analysis (DTA), thermogravimetry (TG), and magnetic measurements.

The miscibility of polyethylene terephthalate (PET)/polylactide (PLA) blends is studied through atomistic molecular dynamics (MD) and mesoscale dissipative particle dynamics (DPD) simulation. Five PET/PLA blends (with the weight ratio at 90/10, 70/30, 50/50, 30/70 and 10/90) as well as pure PET and PLA are examined. The solubility parameter values obtained by using the MD simulation are in good agreement with the reference data. The Flory–Huggins parameters, χ, which are computed for different blends and determined from the cohesive energy densities, with the radial distribution functions g(r) of the inter-molecular atoms, suggest that PET is completely miscible with PLA over the entire composition range. This is further proved by the mesoscopic morphologies of PET/PLA blends. All the simulation results are qualitatively consistent with the experimental results, and demonstrate that the modelling strategies in this study may serve as a powerful tool for predicting miscibility and mesoscopic morphology of ...