The Connection between the Properties of Elements and Compounds; Mineralogical-Crystallochemical Classification of Elements

The described mineralogical-crystallochemical classification bears some similar features with geochemical classification of elements. This similarity emphasizes a greater importance in conforming the vast practical data on petrology. The present classification also bears some resemblance to the technical classification of elements by Berg (1929). The similarity seems logical since the mineralogical. crystallochemical classification of elements unites them on the basis of crystallochemical similarity, determining the type of chemical bonds of the formed compounds, the possibility of crystalline substances. In their turn they determine the common mineral genesis in one mineralogical-crystallochemical group of elements, their co-existence in ores and chemical raw materials and the possiblity of formation of alloys

Synthesis of CF₃-Containing Spiro-[Indene-Proline] Derivatives via Rh(III)-Catalyzed C-H Activation/Annulation

An efficient method of accessing new CF3-containing spiro-[indene-proline] derivatives has been developed based on a Cp*Rh(III)-catalyzed tandem C-H activation/[3+2]–annulation reaction of 5-aryl-2-(trifluoromethyl)-3,4-dihydro-2H-pyrrole-2-carboxylates with alkynes. An important feature of this spiro annulation process is the feasibility of dehydroproline moiety to act as a directing group in the selective activation of the aromatic C-H bond

Synthesis, characterization and anti-HIV activity of polycarboxylic [60]fullerene derivatives obtained in the reaction of C60Cl6 with a hydroquinone ethere

status: publishe

Direct arylation of C60Cl6 and C70Cl8 with carboxylic acids: a synthetic avenue to water-soluble fullerene derivatives with promising antiviral activity

We report unprecedented Friedel-Crafts arylation of chlorofullerenes C60Cl6 and C70Cl8 with unprotected carboxylic acids as an efficient single-step synthesis of the inherently stable water-soluble fullerene derivatives. Using this method, a series of previously unaccessible compounds was obtained without chromatographic purification in almost quantitative yields. Promising anti-HIV activity comparable to characteristics of commercial drugs was demonstrated for some of these compounds.status: publishe

Thiophene-based water-soluble fullerene derivatives as highly potent antiherpetic pharmaceuticals

Here we report the Friedel-Crafts arylation of chlorofullerenes C60Cl6 and C70Cl8 with thiophene-based methyl esters. While C60Cl6 formed expected Cs-C60R5Cl products, C70Cl8 demonstrated a tendency for both substitution of chlorine atoms and addition of an extra thiophene unit, thus forming Cs-C70R8 and C1-C70R9H compounds. The synthesized water-soluble C60 and C70 fullerene derivatives with thiophene-based addends demonstrated high activity against a broad range of viruses, including human immunodeficiency virus, influenza virus, cytomegalovirus, and herpes simplex virus. The record activity of C70 fullerene derivatives against herpes simplex virus together with low toxicity in mice makes them promising candidates for the development of novel non-nucleoside antiherpetic drugs.status: publishe

Methylsulfanyl-Stabilized Rotamers of Cobalt Bis(dicarbollide)

Methylsulfanyl derivatives of cobalt bis(dicarbollide), [8,8â\u80²-(MeS)2-3,3â\u80²-Co(1,2-C2B9H10)2]â\u80\u93, [4,4â\u80²-(MeS)2-3,3â\u80²-Co(1,2-C2B9H10)2]â\u80\u93, and [4,7â\u80²-(MeS)2-3,3â\u80²-Co(1,2-C2B9H10)2]â\u80\u93, were synthesized through the reactions of CoCl2with [10-MeS-7,8-C2B9H11]â\u80\u93and [9-MeS-7,8-C2B9H11]â\u80\u93in strong alkaline aqueous media. The 4,4â\u80²-(rac) and 4,7â\u80²-(meso) isomers were separated by column chromatography as the tetrabutylammonium salts. The structures of [Bu4N][8,8â\u80²-(MeS)2-3,3â\u80²-Co(1,2-C2B9H10)2], [Bu4N][4,4â\u80²-(MeS)2-3,3â\u80²-Co(1,2-C2B9H10)2], and [Bu4N][4,7â\u80²-(MeS)2-3,3â\u80²-Co(1,2-C2B9H10)2] were determined through single-crystal X-ray diffraction. In the solid state, the rotation of the two dicarbollide ligands with respect to each other is hampered by the formation of intramolecular CH···S(Me) hydrogen bonds between the ligands, and this results in the stabilization of definite rotamers, namely, the transoid conformation for the 8,8â\u80² isomer and the gauche conformations for the 4,4â\u80² and 4,7â\u80² isomers. These data are in a good agreement with the results of quantum-chemical calculations

Distorted <i>commo</i>-Cobaltacarboranes Based on the 5,6-Dicarba-<i>nido</i>-decaborane(12): The First Bimetal Cobalt–Copper Zwitterion-Containing Cluster with Four (B–H)₄···Cu Bonds Not Showing Fluxional Behavior in Solution

Treatment of a recently reported complex [Ph₄P]­[<i>closo,nido-</i>CoH­(2,4-C₂B₈H₁₀)­(7,8-C₂B₈H₁₁)] (<b>1</b>) either by H₂O₂ in acetone or NaH in THF leads to the loss of both the bridging and terminal hydrides yielding the diamagnetic salt of an anionic <i>commo</i>-cobaltacarborane [Ph₄P]­[Co­(2,4-<i>isonido</i>-C₂B₈H₁₀)₂] (<b>2</b>) with the {CoC₂B₈}-cluster units adopting a distorted skeletal geometry of the <i>isonido</i>-type. The anionic <i>commo</i> complex <b>2</b> reacts with in situ generated cationic [CuPPh₃]⁺ species to give stable copper–cobalt zwitterion [Ph₃PCu]­[Co­(2,4-<i>isonido</i>-C₂B₈H₁₀)₂] (<b>3</b>) with four two-electron, three-center (B–H)₄···Cu bonds, and exhibits no fluxional behavior in solution. Complex <b>3</b>, at the same time, in CH₂Cl₂ in the presence of 2-fold excess of PPh₃ readily converts to a new anionic species [(Ph₃P)₃Cu]­[Co­(2,4-<i>isonido</i>-C₂B₈H₁₀)₂] (<b>4</b>) which retains initial <i>isonido</i> geometry. All newly obtained diamagnetic <i>commo</i> complexes were characterized by a combination of analytical and multinuclear NMR spectroscopic data and by single-crystal X-ray diffraction studies of complexes <b>2</b> and <b>3</b>

Exploitation of knowledge databases in the synthesis of zinc(II) malonates with photo-sensitive and photo-insensitive N,N′-containing linkers

Photoinitiated solid-state reactions are known to affect the physical properties of coordination polymers, such as fluorescence and sorption behaviour, and also afford extraordinary architectures (e.g. three-periodic structures with polyorganic ligands). However, the construction of novel photo-sensitive coordination polymers requires an understanding of the factors which govern the mutual disposition of reactive fragments. A series of zinc(II) malonate complexes with 1,2-bis(pyridin-4-yl)ethylene and its photo-insensitive analogues has been synthesized for the purpose of systematic analysis of their underlying nets and mutual disposition of N-donor ligands. The application of a big data-set analysis for the prediction of a variety of possible complex compositions, coordination environments and networks for a four-component system has been demonstrated for the first time. Seven of the nine compounds possess one of the highly probable topologies for their underlying nets; in addition, two novel closely related four-coordinated networks were obtained. Complexes containing 1,2-bis(pyridin-4-yl)ethylene and 1,2-bis(pyridin-4-yl)ethane form isoreticular compounds more readily than those with 4,4′-bipyridine and 1,2-bis(pyridin-4-yl)ethylene. The effects of the precursor, either zinc(II) nitrate or zinc(II) acetate, on the composition and dimensionality of the resulting architecture are discussed. For three of the four novel complexes containing 1,2-bis(pyridin-4-yl)ethylene, the single-crystal-to-single-crystal [2 + 2] cycloaddition reactions were carried out. UV irradiation of these crystals afforded either the 0D→1D or the 3D→3D transformations, with and without network changes. One of the two 3D→3D transformations was accompanied by solvent (H2O) cleavage