Spin crossover in phosphorus- and arsenic-bridged cyclopentadienyl-manganese(II) dimers

Manganocene reacts with LiE(SiMe(3))(2) (E = P or As) to give [(η(5)-Cp)Mn{μ-E(SiMe(3))(2)}](2), where E = P (1) or As (2). The temperature dependence of the magnetic susceptibility in 1 and 2 is due to antiferromagnetic exchange and to spin-crossover (SCO). Compound 2 shows two-step SCO with hysteresis, involving high-spin (S = 5/2) and intermediate-spin S = (3/2) Mn(II).     

A high anisotropy barrier in a sulfur-bridged organodysprosium single-molecule magnet

The sulfur-bridged dimers [{Cp'(2)Ln(μ-SSiPh(3))}(2)] (Ln=Gd (1), Dy (2); Cp'=η(5)-C(5)H(4)Me) were synthesized by the transmetalation reactions between [Cp'(3)Ln] and Ph(3)SiSLi. Compound 2 is a single-molecule magnet with slow relaxation of magnetization up to 40 K and an anisotropy barrier of U(eff) =133 cm(-1). Insight into the SMM properties of 2 and closely related SMMs has been obtained using ab initio calculations.     

Addition of cement kiln dust in ceramic wall tile bodies

Journal of Thermal Analysis and Calorimetry - The volume of wastes generated from heavy industries, such as cement and steel industries, is increasing, and the cost of landfill disposal grows...     

Analytical derivation of the impulse response for the bounded 2-D diffusion channel

This letter focuses on the derivation of the hitting probabilities of diffusing particles absorbed by an agent in a bounded environment. In particular, we analogously consider the impulse response of a molecular communication channel in a 2-D and 3-D environment. In 2-D, the channel involves a point transmitter that releases molecules to a circular absorbing receiver that absorbs incoming molecules in an environment surrounded by a circular reflecting boundary. Considering this setup, the joint distribution of the molecules on the circular absorbing receiver with respect to time and angle is derived. Using this distribution, the channel characteristics are examined. Then, we extend this channel model to 3-D using a cylindrical receiver and investigate the channel properties. We also propose how to obtain an analytic estimate for the unbounded 2-D channel from our derived solutions, as no analytic derivation for this channel is present in the literature. Throughout the letter, we perform particle-based simulations to compare the analytic results and lay evidence for our findings.     

A homospin iron(II) single chain magnet

Synthetic, structural and magnetic studies of a new Fe(II) single chain magnet are reported.     

Synthesis of new polymetallic iron(III) clusters containing polycarboxylate ligands based on cavity-blocked cyclen

The synthesis and magnetic properties of enneametallic and octametallic Fe(III) cage complexes from tetraazamacrocycle ligands (1,7-H2DO2A) and (H3DO3A) respectively, are reported.     

One-dimensional and two-dimensional coordination polymers constructed from copper(II) nodes and polycarboxylato spacers: Synthesis,crystal structures and magnetic properties

Four new coordination polymers were obtained by employing polycarboxylato spacers and cationic copper(II) complexes as nodes: ^∞₂[Cu₃(trim)₂(NH₃)₆(H₂O)₃] (1); ^∞₁[Cu(tmen)(dhtp)] (2), ^∞₁[Cu(tmen)(hitp)(H₂O)] (3), ^∞₁[Cu(tmen)(nitp)] (4). (H₃trim = trimesic acid, H₂dhtp = 2,5-dihydroxy-terephthalic acid; H₂hitp = 5-hydroxy-isophthalic acid, H₂nitp = 5-nitro-isophthalic acid; tmen = N,N,N′,N′-tetramethyl-ethylenediamine). The crystal structures of the four compounds have been solved. Compound 1 consists of 2D coordination polymers with heart-shaped meshes, while compounds 2–4 contain infinite zigzag chains. The role of the hydrogen bond interactions in sustaining the supramolecular solid-state architectures in compounds 1 and 3 is discussed. The cryomagnetic investigation of compounds 1, 2, and 4 reveals antiferromagnetic interactions between the copper ions.     

Actinide–Pnictide (An−Pn) Bonds Spanning Non‐Metal,Metalloid, and Metal Combinations (An=U,Th; Pn=P,As, Sb,Bi)

The synthesis and characterisation is presented of the compounds [An(Tren^DMBS){Pn(SiMe₃)₂}] and [An(Tren^TIPS){Pn(SiMe₃)₂}] [Tren^DMBS=N(CH₂CH₂NSiMe₂Bu^t)₃, An=U, Pn=P, As, Sb, Bi; An=Th, Pn=P, As; Tren^TIPS=N(CH₂CH₂NSiPrⁱ₃)₃, An=U, Pn=P, As, Sb; An=Th, Pn=P, As, Sb]. The U?Sb and Th?Sb moieties are unprecedented examples of any kind of An?Sb molecular bond, and the U?Bi bond is the first two‐centre‐two‐electron (2c–2e) one. The Th?Bi combination was too unstable to isolate, underscoring the fragility of these linkages. However, the U?Bi complex is the heaviest 2c–2e pairing of two elements involving an actinide on a macroscopic scale under ambient conditions, and this is exceeded only by An?An pairings prepared under cryogenic matrix isolation conditions. Thermolysis and photolysis experiments suggest that the U?Pn bonds degrade by homolytic bond cleavage, whereas the more redox‐robust thorium compounds engage in an acid–base/dehydrocoupling route.