Open AccessArticle
Structural Study of Mismatched Disila-Crown Ether Complexes
Inorganics 2017, 5(1), 11; doi:10.3390/inorganics5010011 -
Abstract
Mismatched complexes of the alkali metals cations Li+ and Na+ were synthesized from 1,2-disila[18]crown-6 (1 and 2) and of K+ from 1,2,4,5-tetrasila[18]crown-6 (4). In these alkali metal complexes, not all crown ether O atoms participate in
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Mismatched complexes of the alkali metals cations Li+ and Na+ were synthesized from 1,2-disila[18]crown-6 (1 and 2) and of K+ from 1,2,4,5-tetrasila[18]crown-6 (4). In these alkali metal complexes, not all crown ether O atoms participate in the coordination, which depicts the coordination ability of the C-, Si/C-, and Si-bonded O atoms. Furthermore, the inverse case—the coordination of the large Ba2+ ion by the relatively small ligand 1,2-disila[15]crown-5—was investigated, yielding the dinuclear complex 5. This structure represents a first outlook on sandwich complexes based on hybrid crown ethers. Full article
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Open AccessArticle
A Cancer Stem Cell Potent Cobalt(III)–Cyclam Complex Bearing Two Tolfenamic Acid Moieties
Inorganics 2017, 5(1), 12; doi:10.3390/inorganics5010012 -
Abstract
Cancer stem cells (CSCs) are thought to be responsible for cancer relapse. CSCs are a subtype of cancer cells with the ability to differentiate, self-renew, and form secondary or tertiary tumors. Current cancer treatments—including chemotherapy, radiation, and surgery—effectively remove bulk cancer cells but
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Cancer stem cells (CSCs) are thought to be responsible for cancer relapse. CSCs are a subtype of cancer cells with the ability to differentiate, self-renew, and form secondary or tertiary tumors. Current cancer treatments—including chemotherapy, radiation, and surgery—effectively remove bulk cancer cells but are unable to eliminate CSCs. Here, we present the synthesis, characterization, and anti-CSC properties of a cobalt(III)–cyclam complex bearing two tolfenamic acid moieties, 3. Notably, 3 displays sub-micromolar potency towards breast CSCs and bulk breast cancer cells. Detailed mechanistic studies show that 3 is taken up readily by breast CSCs, enters the nucleus, causes DNA damage, and induces caspase-dependent apoptosis. Furthermore, 3 inhibits cyclooxygenase-2 (COX-2) expression in CSCs. The mechanism of action of 3 is similar to that of a naproxen-appended cobalt(III)–cyclam complex, 1 recently reported by our group. The advantage of 3 over 1 is that it has the potential to remove whole tumor populations (bulk cancer cells and CSCs) with a single dose. Full article
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Open AccessArticle
Synthesis, Crystal Structure, Polymorphism, and Magnetism of Eu(CN3H4)2 and First Evidence of EuC(NH)3
Inorganics 2017, 5(1), 10; doi:10.3390/inorganics5010010 -
Abstract
We report the first magnetically coupled guanidinate, α-Eu(CN3H4)2 (monoclinic, P21, a = 5.8494(3) Å, b = 14.0007(8) Å, c = 8.4887(4) Å, β = 91.075(6)°, V = 695.07(6) Å3, Z = 4). Its
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We report the first magnetically coupled guanidinate, α-Eu(CN3H4)2 (monoclinic, P21, a = 5.8494(3) Å, b = 14.0007(8) Å, c = 8.4887(4) Å, β = 91.075(6)°, V = 695.07(6) Å3, Z = 4). Its synthesis, polymorphism, crystal structure, and properties are complemented and supported by density-functional theory (DFT) calculations. The α-, β- and γ-polymorphs of Eu(CN3H4)2 differ in powder XRD, while the γ-phase transforms into the β-form over time. In α-Eu(CN3H4)2, Eu is octahedrally coordinated and sits in one-dimensional chains; the guanidinate anions show a hydrogen-bonding network. The different guanidinate anions are theoretically predicted to adopt syn-, anti- and all-trans-conformations. Magnetic measurements evidence ferromagnetic interactions, presumably along the Eu chains. Finally, EuC(NH)3 (isostructural to SrC(NH)3 and YbC(NH)3, hexagonal, P63/m, a = 5.1634(7) Å, c = 7.1993(9) Å, V = 166.23(4) Å3, Z = 2) is introduced as a possible ferromagnet. Full article
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Open AccessArticle
Flux Synthesis, Crystal Structures, and Magnetism of the Series La2n+2MnSen+2O2n+2 (n = 0–2)
Inorganics 2017, 5(1), 9; doi:10.3390/inorganics5010009 -
Abstract
Three members of the homologous series of manganese oxyselenides with the general formula La2n+2MnSen+2O2n+2 (n = 0–2) have been synthesized in a NaI/KI flux and characterized by single-crystalX-raydiffraction,powderX-raydiffractionandmagneticmeasurements. Thestructures consist of chains of edge-sharing MnSe4O2-octahedra along the b-axis which are linked together along
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Three members of the homologous series of manganese oxyselenides with the general formula La2n+2MnSen+2O2n+2 (n = 0–2) have been synthesized in a NaI/KI flux and characterized by single-crystalX-raydiffraction,powderX-raydiffractionandmagneticmeasurements. Thestructures consist of chains of edge-sharing MnSe4O2-octahedra along the b-axis which are linked together along the a-axis by edge-sharing OLa4- and/or OLa3Mn-tetrahedra forming infinite ribbons of increasing width. mC-La2MnSe2O2 (Pb2HgCl2O2-type, C2/m, a = 11.6621(5) Å, b = 3.9719(1) Å, c = 7.2049(3) Å, β = 121.655(2)◦) represents a new polymorph of this compound. La4MnSe3O4 (P2/m, a = 9.0055(4) Å, b = 4.0186(1) Å, c = 7.1946(3) Å, β = 109.715(2)◦) and La6MnSe4O6 (C2/m, a = 24.760(2) Å,b = 4.0359(3)Å,c=7.1850(6)Å, β =104.162(3)◦)exhibitnewstructuretypes. Magnetic measurements suggest antiferromagnetic order of the moments below about 15 K with effective magnetic moments of 5.53(1), 5.99(1) and 6.01(1) µB per formula unit for n = 1, 2 and 3, respectively. Full article
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Open AccessArticle
Manganese(I)-Based CORMs with 5-Substituted 3-(2-Pyridyl)Pyrazole Ligands
Inorganics 2017, 5(1), 8; doi:10.3390/inorganics5010008 -
Abstract
The reaction of [(OC)5MnBr] with substituted 3-(2-pyridyl)pyrazoles) 2-PyPzRH (1a-l) in methanol or diethyl ether yields the yellow to orange manganese(I) complexes [(OC)3Mn(Br)(2-PyPzRH)] (2a-l), the substituents R being
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The reaction of [(OC)5MnBr] with substituted 3-(2-pyridyl)pyrazoles) 2-PyPzRH (1a-l) in methanol or diethyl ether yields the yellow to orange manganese(I) complexes [(OC)3Mn(Br)(2-PyPzRH)] (2a-l), the substituents R being phenyl (a), 1-naphthyl (b), 2-anthracenyl (c), 1-pyrenyl (d), 4-bromophenyl (e), 3-bromophenyl (f), duryl (g), 2-pyridyl (h), 2-furanyl (i), 2-thienyl (j), ferrocenyl (k), and 1-adamantyl (l). The carbonyl ligands are arranged facially, leading to three chemically different CO ligands due to different trans-positioned Lewis donors. The diversity of the substituent R demonstrates that this photoCORM backbone can easily be varied with a negligible influence on the central (OC)3MnBr fragment, because the structural parameters and the spectroscopic data of this unit are very similar for all these derivatives. Even the ferrocenyl complex 2k shows a redox potential for the ferrocenyl subunit which is identical to the value of the free 5-ferrocenyl-3-(2-pyridyl)pyrazole (1k). The ease of variation of the starting 5-substituted 3-(2-pyridyl)pyrazoles) offers a modular system to attach diverse substituents at the periphery of the photoCORM complex. Full article
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Open AccessArticle
Hydrothermal Treatment of Tannin: A Route to Porous Metal Oxides and Metal/Carbon Hybrid Materials
Inorganics 2017, 5(1), 7; doi:10.3390/inorganics5010007 -
Abstract
In the present paper, porous materials were prepared from the hydrothermal treatment of aqueous solutions of tannin, a renewable phenolic resource extracted from tree barks, containing dissolved salts of transition metals: V, Cr, Ni and Fe. Hydrothermal treatment produced carbonaceous particles doped with
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In the present paper, porous materials were prepared from the hydrothermal treatment of aqueous solutions of tannin, a renewable phenolic resource extracted from tree barks, containing dissolved salts of transition metals: V, Cr, Ni and Fe. Hydrothermal treatment produced carbonaceous particles doped with the aforementioned metals, and such materials were treated according to two different routes: (i) calcination in air in order to burn the carbon and to recover porous oxides; (ii) pyrolysis in inert atmosphere so as to recover porous metal/carbon hybrid materials. The nature of the metal salt was found to have a dramatic impact on the structure of the materials recovered by the first route, leading either to nano-powders (V, Cr) or to hollow microspheres (Ni, Fe). The second route was only investigated with iron, leading to magnetic Fe-loaded micro/mesoporous carbons whose texture, pore volumes and surface areas gradually changed with the iron content. Full article
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Open AccessArticle
Influence of Fatty Acid Alkyl Chain Length on Anisotropy of Copper Nitride Nano-Crystallites
Inorganics 2017, 5(1), 6; doi:10.3390/inorganics5010006 -
Abstract
My group developed a simple method to prepare copper nitride fine particles from copper carboxylate in a solvent of long-chain alcohols without the use of high temperatures or high pressures. By selecting copper acetate or copper decanoate as the copper source, my group
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My group developed a simple method to prepare copper nitride fine particles from copper carboxylate in a solvent of long-chain alcohols without the use of high temperatures or high pressures. By selecting copper acetate or copper decanoate as the copper source, my group demonstrated that the morphology of the copper nitride fine particles varied between cubic and plate-like, respectively. Although a hypothesis was proposed to explain the influence of the length of the alkyl chain on the copper decanoate, it is uncertain how much the chain length influences the shape of the fine particles. In this work, I demonstrated the effect of the length of the alkyl chain on particle shape by preparing fine particles from a series of copper sources with different alky chain lengths and characterizing the particles with x-ray diffractometry (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The main findings were as follows: (1) the fine particles were plate-like when the alkyl chain length exceeded 5; (2) the aspect ratio of the plate-like particles increased as the alkyl chain length increased; and (3) growth of the (110) and (111) planes of the copper nitride crystal were selectively inhibited. Full article
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Open AccessArticle
P-Fluorous Phosphines as Electron-Poor/Fluorous Hybrid Functional Ligands for Precious Metal Catalysts: Synthesis of Rh(I), Ir(I), Pt(II), and Au(I) Complexes Bearing P-Fluorous Phosphine Ligands
Inorganics 2017, 5(1), 5; doi:10.3390/inorganics5010005 -
Abstract
P-Fluorous phosphine (R2PRf), in which the perfluoroalkyl group is directly bonded to the phosphorus atom, is a promising ligand because it has a hybrid functionality, i.e., electron-poor and fluorous ligands. However, examples of P-fluorous phosphine–metal complexes are
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P-Fluorous phosphine (R2PRf), in which the perfluoroalkyl group is directly bonded to the phosphorus atom, is a promising ligand because it has a hybrid functionality, i.e., electron-poor and fluorous ligands. However, examples of P-fluorous phosphine–metal complexes are still rare, most probably because the P-fluorous group is believed to decrease the coordination ability of the phosphines dramatically. In contrast, however, we have succeeded in synthesizing a series of P-fluorous phosphine–coordinated metal complexes such as rhodium, iridium, platinum, and gold. Furthermore, the electronic properties of R2PnC10F21 are investigated by X-ray analysis of PtCl2(Ph2PnC10F21)2 and the infrared CO stretching frequency of RhCl(CO)(R2PnC10F21)2. IrCl(CO)(Ph2PnC10F21)2- and AuCl(R2PnC10F21)-catalyzed reactions are also demonstrated. Full article
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Open AccessReview
Anticancer Applications and Recent Investigations of Metallodrugs Based on Gallium, Tin and Titanium
Inorganics 2017, 5(1), 4; doi:10.3390/inorganics5010004 -
Abstract
For more than 100 years metal complexes have been extensively used in therapy and since the discovery of cisplatin the research in this field has expanded exponentially. The scientific community is always in search of new alternatives to platinum compounds and a wide
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For more than 100 years metal complexes have been extensively used in therapy and since the discovery of cisplatin the research in this field has expanded exponentially. The scientific community is always in search of new alternatives to platinum compounds and a wide variety of metallodrugs based on other metals have been reported with excellent therapeutic results. This short review focuses on the work that our research group has carried out since 2007 in collaboration with others and centers on the preparation of organogallium(III) compounds, organotin(IV) derivatives, and titanocene(IV) complexes together with the study of their cytotoxic anticancer properties. Full article
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Open AccessEditorial
Acknowledgement to Reviewers of Inorganics in 2016
Inorganics 2017, 5(1), 3; doi:10.3390/inorganics5010003 -
Abstract The editors of Inorganics would like to express their sincere gratitude to the following reviewers for assessing manuscripts in 2016.[...] Full article
Open AccessArticle
The A-Type Ln4N2S3 Series: New Nitride Sulfides of the Light Lanthanoids (Ln = Ce–Nd)
Inorganics 2017, 5(1), 2; doi:10.3390/inorganics5010002 -
Abstract
The reaction of lanthanoid metal powders (Ln) with sulfur and cesium azide (CsN3) as a nitrogen source in the presence of lanthanoid tribromides (LnBr3) yields lanthanoid nitride sulfides with the composition Ln4N2
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The reaction of lanthanoid metal powders (Ln) with sulfur and cesium azide (CsN3) as a nitrogen source in the presence of lanthanoid tribromides (LnBr3) yields lanthanoid nitride sulfides with the composition Ln4N2S3 (Ln = Ce–Nd) when appropriate molar ratios of the starting material are used. Additional cesium bromide (CsBr) as a flux secures quantitative conversion (7 days) at 900 °C in evacuated silica tubes as well as the formation of black single crystals. All compounds crystallize isotypically with the orthorhombic crystal structure of La4N2S3 (Pnnm, Z = 2) and their structures were determined from single-crystal X-ray diffraction data (Ce4N2S3: a = 644.31(4), b = 1554.13(9), c = 404.20(3) pm; Pr4N2S3: a = 641.23(4), b = 1542.37(9), c = 400.18(3) pm; Nd4N2S3: a = 635.19(4), b = 1536.98(9), c = 397.85(3) pm). Compared to La4N2S3 the a-axes do not fulfill the expectation of the lanthanide contraction. The main feature of the crystal structure comprises N3−-centered (Ln3+)4 tetrahedra arranging as pairs [N2Ln6]12+ of edge-shared [NLn4]9+ units, which are further connected via four vertices to form double chains 1{([NLn4/2]2)6+}. Bundled along [001] like a hexagonal rod packing, they are held together by two crystallographically different S2− anions. Two compounds of a second modification (B-type La4N2S3 and Pr4N2S3) will also be presented and discussed for comparison. Full article
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Open AccessArticle
Modification of Deposited, Size-Selected MoS2 Nanoclusters by Sulphur Addition: An Aberration-Corrected STEM Study
Inorganics 2017, 5(1), 1; doi:10.3390/inorganics5010001 -
Abstract
Molybdenum disulphide (MoS2) is an earth-abundant material which has several industrial applications and is considered a candidate for platinum replacement in electrochemistry. Size-selected MoS2 nanoclusters were synthesised in the gas phase using a magnetron sputtering, gas condensation cluster beam source
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Molybdenum disulphide (MoS2) is an earth-abundant material which has several industrial applications and is considered a candidate for platinum replacement in electrochemistry. Size-selected MoS2 nanoclusters were synthesised in the gas phase using a magnetron sputtering, gas condensation cluster beam source with a lateral time-of-flight mass selector. Most of the deposited MoS2 nanoclusters, analysed by an aberration-corrected scanning transmission electron microscope (STEM) in high-angle annular dark field (HAADF) mode, showed poorly ordered layer structures with an average diameter of 5.5 nm. By annealing and the addition of sulphur to the clusters (by sublimation) in the cluster source, the clusters were transformed into larger, crystalline structures. Annealing alone did not lead to crystallization, only to a cluster size increase by decomposition and coalescence of the primary clusters. Sulphur addition alone led to a partially crystalline structure without a significant change in the size. Thus, both annealing and sulphur addition processes were needed to obtain highly crystalline MoS2 nanoclusters. Full article
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Open AccessArticle
Single Crystal Growth and Anisotropic Magnetic Properties of Li2Sr[Li1 − xFexN]2
Inorganics 2016, 4(4), 42; doi:10.3390/inorganics4040042 -
Abstract
Up to now, investigation of physical properties of ternary and higher nitridometalates has been severely hampered by challenges concerning phase purity and crystal size. Employing a modified lithium flux technique, we are now able to prepare sufficiently large single crystals of the highly
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Up to now, investigation of physical properties of ternary and higher nitridometalates has been severely hampered by challenges concerning phase purity and crystal size. Employing a modified lithium flux technique, we are now able to prepare sufficiently large single crystals of the highly air and moisture sensitive nitridoferrate Li2Sr[Li1xFexN]2 for anisotropic magnetization measurements. The magnetic properties are most remarkable: large anisotropy and coercivity fields of 7 Tesla at T=2 K indicate a significant orbital contribution to the magnetic moment of iron. Altogether, the novel growth method opens a route towards interesting phases in the comparatively recent research field of nitridometalates and should be applicable to various other materials. Full article
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Open AccessArticle
Ammonothermal Synthesis and Crystal Structures of Diamminetriamidodizinc Chloride [Zn2(NH3)2(NH2)3]Cl and Diamminemonoamidozinc Bromide [Zn(NH3)2(NH2)]Br
Inorganics 2016, 4(4), 41; doi:10.3390/inorganics4040041 -
Abstract
The treatment of excess zinc in the presence of ammonium chloride under ammonothermal conditions of 873 K and 97 MPa leads to diamminetriamidodizinc chloride [Zn2(NH3)2(NH2)3]Cl with a two-dimensionally μ-amido-interconnected substructure. Similar reaction conditions
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The treatment of excess zinc in the presence of ammonium chloride under ammonothermal conditions of 873 K and 97 MPa leads to diamminetriamidodizinc chloride [Zn2(NH3)2(NH2)3]Cl with a two-dimensionally μ-amido-interconnected substructure. Similar reaction conditions using ammonium bromide instead of the chloride (773 K, 230 MPa) result in diamminemonoamidozinc bromide [Zn(NH3)2(NH2)]Br with one-dimensional infinite μ-amido-bridged chains. Both compounds were obtained as colorless, very moisture sensitive crystals. Crystal structures and hydrogen bond schemes are analyzed. Raman spectroscopic data of the chloride are reported. Full article
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Open AccessArticle
Synthesis and Characterization of a Sulfonyl- and Iminophosphoryl-Functionalized Methanide and Methandiide
Inorganics 2016, 4(4), 40; doi:10.3390/inorganics4040040 -
Abstract
The synthesis of [H2C(PPh2=NSiMe3)(SO2Ph)] (1) and its mono- and dimetalation are reported. Due to the strong anion-stabilizing abilities of the iminophosphoryl and the sulfonyl group monometalation to 1-K and dimetalation to 1-Li2
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The synthesis of [H2C(PPh2=NSiMe3)(SO2Ph)] (1) and its mono- and dimetalation are reported. Due to the strong anion-stabilizing abilities of the iminophosphoryl and the sulfonyl group monometalation to 1-K and dimetalation to 1-Li2 proceed smoothly with potassium hydride and methyllithium, respectively. Both compounds could be isolated in high yields and were characterized by NMR spectroscopy as well as XRD analysis. The methanide 1-K forms a coordination polymer in the solid state, while in case of the methandiide a tetrameric structure is observed. The latter features an unusual structural motif consisting of two (SO2Li)2 eight-membered rings, which are connected with each other via the methandiide carbon atoms and additional lithium atoms. With increasing metalation a contraction of the P–C–S linkage is observed, which is well in line with the increased charge at the central carbon atom and involved electrostatic interactions. Full article
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Open AccessArticle
Reduction of Bromo- and Iodo-2,6-bis(diphenylphosphanylmethyl)benzene with Magnesium and Calcium
Inorganics 2016, 4(4), 39; doi:10.3390/inorganics4040039 -
Abstract
Arylmagnesium and -calcium reagents are easily accessible; however, ether degradation processes limit storability, especially of the calcium-based heavy Grignard reagents. Ortho-bound substituents with phosphanyl donor sites usually block available coordination sites and stabilize such complexes. The reaction of bromo-2,6-bis(diphenylphosphanylmethyl)benzene (1a) with
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Arylmagnesium and -calcium reagents are easily accessible; however, ether degradation processes limit storability, especially of the calcium-based heavy Grignard reagents. Ortho-bound substituents with phosphanyl donor sites usually block available coordination sites and stabilize such complexes. The reaction of bromo-2,6-bis(diphenylphosphanylmethyl)benzene (1a) with magnesium in tetrahydrofuran yields [Mg{C6H3-2,6-(CH2PPh2)2}2] (2) after recrystallization from 1,2-dimethoxyethane. However, the similarly performed reduction of bromo- (1a) and iodo-2,6-bis(diphenylphosphanylmethyl)benzene (1b) with calcium leads to ether cleavage and subsequent degradation products. α-Deprotonation of tetrahydrofuran (THF) yields 1,3-bis(diphenylphosphanylmethyl)benzene. Furthermore, the insoluble THF adducts of dimeric calcium diphenylphosphinate halides, [(thf)3Ca(X)(µ-O2PPh2)]2 [X = Br (3a), I (3b)], precipitate verifying ether decomposition and cleavage of P–C bonds. Ether adducts of calcium halides (such as [(dme)2(thf)CaBr2] (4)) form, supporting the initial Grignard reaction and a subsequent Schlenk-type dismutation reaction. Full article
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Open AccessReview
Structural Classification of Quasi-One-Dimensional Ternary Nitrides
Inorganics 2016, 4(4), 37; doi:10.3390/inorganics4040037 -
Abstract
This review focuses on the crystal structural features of ternary (mixed-metal) quasi-one-dimensional nitrides i.e., nitrides containing (cation-N3−) coordination polyhedra sharing either corners, edges, or faces, arranged in linear chains, and intercalated by a counter ion. The current relevance of these nitrides,
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This review focuses on the crystal structural features of ternary (mixed-metal) quasi-one-dimensional nitrides i.e., nitrides containing (cation-N3−) coordination polyhedra sharing either corners, edges, or faces, arranged in linear chains, and intercalated by a counter ion. The current relevance of these nitrides, and of quasi-one-dimensional compounds in general, lies in the fact that they are closely related to the pure one-dimensional systems (i.e., nanowires), which are vastly researched for their amazing properties closely related to their low dimensionality. A number of these properties were firstly discovered in quasi-one-dimensional compounds, highlighting the importance of expanding knowledge and research in this area. Furthermore, unlike oxides, nitrides and other non-oxide compounds are less developed, hence more difficult to categorise into structural classes that can then be related to other classes of compounds, leading to a fuller picture of structure–properties relationship. Within this context, this review aims to categorise and describe a number of ternary (mixed-metal) quasi-one-dimensional nitrides according to their structural features, specifically, the polyhedra forming the one-dimensional chains. Full article
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Open AccessArticle
Steroid-Functionalized Titanocenes: Docking Studies with Estrogen Receptor Alpha
Inorganics 2016, 4(4), 38; doi:10.3390/inorganics4040038 -
Abstract
Estrogen receptor alpha (ERα) is a transcription factor that is activated by hormones, with 17β-estradiol being its most active agonist endogenous ligand. ERα is also activated or inactivated by exogenous ligands. ER is overexpressed in hormone-dependent breast cancer, and one of the treatments
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Estrogen receptor alpha (ERα) is a transcription factor that is activated by hormones, with 17β-estradiol being its most active agonist endogenous ligand. ERα is also activated or inactivated by exogenous ligands. ER is overexpressed in hormone-dependent breast cancer, and one of the treatments for this type of cancer is the use of an ER antagonist to halt cell proliferation. We have previously reported four steroid-functionalized titanocenes: pregnenolone, dehydroepiandrosterone (DHEA), trans-androsterone, and androsterone. These steroids have hormonal activity as well as moderate antiproliferative activity, thus these steroids could act as vectors for the titanocene dichloride to target hormone-dependent cancers. Also, these steroids could increase the antiproliferative activity of the resulting titanocenes based on synergism. In order to elucidate which factors contribute to the enhanced antiproliferative activity of these steroid-functionalized titanocenes, we performed docking studies between ERα and the titanocenes and the steroids. The binding affinities and type of bonding interactions of the steroid-functionalized titanocenes with ERα are herein discussed. Full article
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Open AccessArticle
PP-Rotation, P-Inversion and Metathesis in Diphosphines Studied by DFT Calculations: Comments on Some Literature Conflicts
Inorganics 2016, 4(4), 36; doi:10.3390/inorganics4040036 -
Abstract
The potential energy surface for internal rotation about the phosphorus–phosphorus bond was calculated at the PCMDCM/B3LYP/6-311++G(d,p) computational level for a set of eight symmetrical, unsymmetrical and P-stereogenic diphosphines; H4P2, Me4P2, (CF3
[...] Read more.
The potential energy surface for internal rotation about the phosphorus–phosphorus bond was calculated at the PCMDCM/B3LYP/6-311++G(d,p) computational level for a set of eight symmetrical, unsymmetrical and P-stereogenic diphosphines; H4P2, Me4P2, (CF3)4P2, Ph4P2, Me2P–P(CF3)2, Me2P–PPh2, and the meso- and dl-isomers of Me(CF3)P–PMe(CF3) and MePhP–PMePh. Certain trends in the data were elucidated and compared with conflicting data from the literature regarding the relative population of anti and gauche rotational isomers. The pyramidal inversion barriers (stereomutation barriers in P-stereogenic cases) for the same set of diphosphines was estimated through the inversion transition states and also compared to literature values. Finally, the Me4P2 + (CF3)4P2 → 2Me2(CF3)2P2 metathesis reaction was also explored to evaluate its feasibility versus inversion. The finding of larger barriers in the metathesis than in the inversion rules in favour of an inversion mechanism for the stereomutation of P-stereogenic diphosphines. Full article
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Open AccessArticle
In Situ Studies and Magnetic Properties of the Cmcm Polymorph of LiCoPO4 with a Hierarchical Dumbbell-Like Morphology Synthesized by Easy Single-Step Polyol Synthesis
Inorganics 2016, 4(4), 35; doi:10.3390/inorganics4040035 -
Abstract
LiCoPO4 (LCP) exists in three different structural modifications: LCP-Pnma (olivine structure), LCP-Pn21a (KNiPO4 structure type), and LCP-Cmcm (Na2CrO4 structure type). The synthesis of the LCP-Cmcm polymorph has been reported via high
[...] Read more.
LiCoPO4 (LCP) exists in three different structural modifications: LCP-Pnma (olivine structure), LCP-Pn21a (KNiPO4 structure type), and LCP-Cmcm (Na2CrO4 structure type). The synthesis of the LCP-Cmcm polymorph has been reported via high pressure/temperature solid-state methods and by microwave-assisted solvothermal synthesis. Phase transitions from both LCP-Pn21a and LCP-Cmcm to LCP-Pnma upon heating indicates a metastable behavior. However, a precise study of the structural changes during the heating process and the magnetic properties of LCP-Cmcm are hitherto unknown. Herein, we present the synthesis and characterization of LCP-Cmcm via a rapid and facile soft-chemistry approach using two different kinetically controlled pathways, solvothermal and polyol syntheses, both of which only require relatively low temperatures (~200 °C). Additionally, by polyol, method a dumbbell-like morphology is obtained without the use of any additional surfactant or template. A temperature-dependent in situ powder XRD shows a transition from LCP-Cmcm at room temperature to LCP-Pnma and finally to LCP-Pn21a at 575 and 725 °C, respectively. In addition to that, the determination of the magnetic susceptibility as a function of temperature indicates a long-range antiferromagnetic order below TN = 11 K at 10 kOe and 9.1 K at 25 kOe. The magnetization curves suggests the presence of a metamagnetic transition. Full article
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