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Chirality has an important role in the drug design because enantiomers may exhibit different bioactivity when interacting with macromolecules of a living organism. In our previous work, based on the analysis of a set of 100 chiral drugs, a relationship was established between the sign of chirality of enantiomers and their bioactivity. To understand the reasons for the observed patterns of chiral specificity of drug enantiomers, the interaction of 10 enantiomeric pairs of chiral drugs with the corresponding target proteins has been considered using molecular docking and further postprocessing by quantum chemistry methods. The data obtained confirm that the energetic aspect of the interaction between opposite enantiomers and target protein affects the enantiomer biological activity. In addition, the results show that molecular docking is able to distinguish between bioactive and inactive/less active enantiomers, although many docking programs are not accurate enough to distinguish a weak inhibitor from a strong one. [ABSTRACT FROM AUTHOR]

The reactions of chromium(III) nitrate with M2(cpdc) (cpdc2− – dianion of cyclopropane-1,1-dicarboxylic acid, M = K, Na) and rare-earth metal nitrates taken in a molar ratio of 1 : 3 : 1 yielded heterometallic coordination polymers {[Ln2Cr2(cpdc)6(H2O)9]·8.5H2O}n (1Ln, Ln = Eu, Gd, Tb), crystallizing in tetragonal space group P43212 (P41212). A single crystal X-ray diffraction (XRD) study showed that the crystal structures of these compounds are formed by tris-chelate fragments {Cr(cpdc)3} linked into {Ln–Cr} layers and further into a 3D framework structure due to the bridging coordination of carboxylate groups to Ln atoms. When passing to Ln = Dy, Ho, Y, Er, Yb, the crystals of compounds 2Ln form, where the structure of {Ln–Cr} layers is retained, but the disorder of the interlayer Ln atoms, a decrease in the size of a crystal cell, and a change in the space group to I4 are observed. The use of K2(cpdc) in the syntheses of 1Ln and 2Ln is found to lead to the isolation of a side product, namely, mononuclear complex [Cr(cpdc)(Hcpdc)(H2O)2]·2H2O (3), with the reactions with Na2(cpdc) enabling obtaining only the crystals of heterometallic LnIII–CrIII compounds. Alternating current magnetic susceptibility measurements for the series 1Ln and 2Ln revealed the presence of slow relaxation of magnetization only for 1Eu and 2Y, which is due to the magnetic anisotropy of chromium ions in the presence of magnetic field and their magnetic isolation in a crystal lattice. For 1Eu, 1Gd, 1Tb, 2Dy, and 2Ho, thermal decomposition in an Ar atmosphere was studied. The end product of solid-state thermolysis of 2Dy in air at 1000 °C is shown to be submicron DyCrO3 particles (300–400 nm). [ABSTRACT FROM AUTHOR]

A series of Ba–MII complexes with allylmalonic acid anions (Amal) [BaMII(Amal)2(H2O)3]n (MII = Mn (1), Co (2), Cu (3), and Zn (4)) were synthesized by the reaction of the corresponding transition metal sulfates and barium allylmalonate. The complexes were characterized by IR and EPR spectroscopy, elemental analysis, magnetochemical and solid phase thermal decomposition studies as well as powder and single-crystal X-ray crystallography. The main structural block {MII(Amal)2(H2O)x} (x = 1 for M = Cu, x = 2 for M = Mn, Co, and Zn) in 1–4 is formed by two chelate allylmalonate anions and water molecule(s), which are surrounded by Ba2+ ions. The magnetic measurements of paramagnetic compounds revealed weak ferromagnetic interactions between copper(II) ions in 3, and slow magnetic relaxation in non-zero field (HDC = 1500 Oe) for 2. According to the TGA data of 1–4, they are decomposed via different pathways in the case of MnII, CoII, CuII, and ZnII since the metal ions catalyze different types of processes. However, all the complexes undergo polymerization of the allyl fragment. [ABSTRACT FROM AUTHOR]

Perovskite LaNiO3 is of immense significance in a range of fields such as heterogeneous catalysis. Herein, new convenient approach for preparing LaNiO3via thermolysis of new simple complexes, [Ni (bpy)3] [La (NO3)5(MeCN)] (1, bpy is 2,2'‐bipyridine) and [Ni (phen)3] [La (NO3)5(H2O)]·2MeCN (2, phen is 1,10‐phenanthroline), is reported. These first examples of unambiguously characterized LaNiO3 precursors are chemically stable and can be synthesized rapidly in good yields. While virtually monophasic LaNiO3 can be prepared from 2via only 3‐h annealing on air at 800°C, there are always minor admixtures in oxide samples prepared from 1. Peculiarities of intrinsic thermal transformations of 1 and 2 affecting such difference have been revealed. Thus, 1 and 2 are the first series of compositionally related heterometallic La‐Ni complexes studied as precursors for LaNiO3‐based ceramics. Comparatively high surface areas of LaNiO3‐based ceramics produced from 1 and 2 at 800°C determine its high catalytic activity towards dry reforming of methane (DRM) to syngas. Nearly quantitative CH4 and CO2 conversions as well as CO and H2 yields were achieved in 800–900°C range without preliminary reduction to Ni/La2O3 composites. Thus, LaNiO3‐based ceramics prepared from 1 and 2 are good precursors for in situ production of efficient catalysts for DRM. [ABSTRACT FROM AUTHOR]

Carboxycymantrene CymCOOH (Cym = (η5‐C5H4)Mn (CO)3) was applied to assemble a series of uncommon Cd‐Mn carboxylate complexes comprising 1D‐polynuclear [Cd (OOCCym)(acac)]n (1) as well as oligonuclear species, [Cd2(OOCCym)4(EtOH)4)] (2), [Cd (OOCCym)2(bpy)(H2O] (3, bpy = 2,2′‐bipyridine) and [Cd (OOCCym)2(phen)2]·EtOH (4, phen = 1,10‐phenantroline). Compound 2 was found to be a product of irreversible SCSC transition from [Cd2(OOCCym)4(EtOH)3(H2O)]·EtOH (2_100K) initially formed in corresponding syntheses. This transition is accompanied by two‐fold decrease in cell volume and increase in cell symmetry. Recrystallyzation of 2–4 from common organic solvents affects the nuclearity of products (in case of 2 and 3) or subtly alters the structure of [Cd (OOCCym)2(phen)2] units (4). The optimal Cd to Mn ratio inspired studying solid‐state thermal decomposition of 2–4 as a route to CdMn2O4‐based ceramics. As a result, oxide samples with a predominance of tetragonal (Cd1‐xMnx)Mn2O4 spinel have been prepared and characterized by powder XRD, SEM, EDX, and IR revealing the interplay between the preparation technique and the features of morphology and composition. The retaining of Cd to Mn ratio upon recrystallyzation of 2–4 implies possibility of further elaboration of CdMn2O4‐based materials in various morphologies (polycrystalline ones, films, etc.). Notably, 2–4 is also the first series of related heterometallic Cd‐Mn complexes being studied as individual precursors for CdMn2O4‐based oxide systems. [ABSTRACT FROM AUTHOR]

Exchange reactions of LnCl3 and CymCO2K in aqueous‐organic medium in the presence of diethylene glycol (DEG) bring about isostructural tetranuclear cluster complexes with linear core, [Ln4(CymCO2)12(O(CH2CH2OH)2)2(H2O)4] ⋅ 2THF (Ln=Nd (1), Gd (2), Tb (3), Dy (4), Ho (5); Cym=(η5‐C5H4)Mn(CO)3). The complexes have centrosymmetric structure and contain two types of Ln3+ coordination centers. Thermal decomposition of the complexes under argon and air atmospheres was studied; in the latter case it brings about mixed oxides LnMn2O5 as one of the products. The complexes 1–5 were characterized by dc‐ and ac‐magnetic measurements. Complexes of Nd, Gd, and Dy exhibit the properties of single‐molecule magnets (SMMs) with remagnetization barriers Δeff/kB of 14 K for 1 under 2500 Oe dc‐field, 13 K for 2 under 1500 Oe dc‐field, and with two barriers, 18 and 19 K, for 4 in zero field. The presence of field‐induced slow relaxation of the magnetization detected for the complex 2 is a rare case for Gd complexes. [ABSTRACT FROM AUTHOR]