The first metallasilsesquioxane bearing pyrazolylpyridine ligands, the Cu-based complex 1, adopts a cage-like structure with two zigzag-type copper tetramers sandwiched by two cyclic Si silsesquioxane ligands. The four 3-phenyl-5-(2-pyridyl)pyrazolate ligands in 1 exhibit dual (chelating and bridging) modes of ligation. Compound 1 is very active in the oxidation of alkanes and alcohols.
View Article and Find Full Text PDFWe report a high nuclear (Cu) complex synthesized via the self-assembly of copper-methylsilsesquioxane induced by the complexation with 1,2-bis(diphenylphosphino)ethane (dppe). The structure includes two cationic Cu(dppe) moieties and an anionic silsesquioxane cage of an unprecedented Cu structural type. The Cu cage fragment exhibits a unique () combination of Si-cyclic/Si-acyclic silsesquioxane ligands and () encapsulation of two different chloride and carbonate species.
View Article and Find Full Text PDFThe synthesis of a high nuclear (CuNa) complex 1 the self-assembly of copper(II) phenylsilsesquioxane induced by complexation with bis(triphenylphosphine)iminium chloride (PPNCl) was successfully achieved. This complex, which includes two bis(triphenylphosphine)iminium PPN cations, represents the first example of a metallasilsesquioxane/phosphazene compound. The CuNa-silsesquioxane cage demonstrates a nontrivial combination of two pairs of Si-cyclic/Si-acyclic silsesquioxane ligands and a fusion of two SiCuNa fragments, combined the central ninth copper ion.
View Article and Find Full Text PDFAn extended (, 19 distinct species) family of cage-like Cu-phenylsilsesquioxanes allowed us to accentuate the general regularities behind their structural organization. Influencing factors, namely the (i) size of external alkali metal ions (from Li to Cs) and (ii) nature of bridging linkers (including the smallest possible ones, like a water molecule) on the self-assembly/supramolecular assembly of such Cu-building blocks have been thoroughly explored. A CuK-based complex has been evaluated as a precatalyst in the oxidation of alkanes (cyclohexane, -heptane, methylcyclohexane) and alcohols.
View Article and Find Full Text PDFWe report the synthesis and single-crystal X-ray diffraction, magnetic, and luminescence measurements of a novel family of luminescent cage-like tetranuclear silsesquioxanes (PhSiO)(LnO)(O)(CHO)(EtOH)(CHCN)⋅2CHCN (where Ln = Tb, ; Tb/Eu, ; and Gd, ), featuring seven-coordinated lanthanide ions arranged in a one-capped trigonal prism geometry. Compounds and exhibit characteristic Tb and Tb/Eu-related emissions, respectively, sensitized by the chelating antenna acetylacetonate (acac) ligands upon excitation in the UV and visible spectral regions. Compound is used to assess the energies of the triplet states of the ligand.
View Article and Find Full Text PDFConvenient self-assembly synthesis of copper(II) complexes via double (phenylsilsesquioxane and acetate) ligation allows to isolate a family of impressive sandwich-like cage compounds. An intriguing feature of these complexes is the difference in the structure of a pair of silsesquioxane ligands despite identical (Cu) nuclearity and number (four) of acetate fragments. Formation of particular combination of silsesquioxane ligands (cyclic/cyclic vs condensed/condensed vs cyclic/condensed) was found to be dependent on the synthesis/crystallization media.
View Article and Find Full Text PDFUnprecedented iron-based silsesquioxane/acetylacetonate complexes were synthesized. The intriguing cage-like structure of compounds is alkaline metal-dependent: the FeLi complex includes condensed Si-silsesquioxane and four acetylacetonate ligands; the FeNa complex exhibits two cyclic Si-silsesquioxane and eight acetylacetonate ligands, while the FeK complex features two cyclic Si-silsesquioxane and six acetylacetonate ligands. The latter case is the very first observation of small trimeric silsesquioxane ligands in the composition of cage-like metallasilsesquioxanes.
View Article and Find Full Text PDFThis study reports a novel family of cage manganesesilsesquioxanes prepared via complexation with bathophenanthroline (4,7-diphenyl-1,10-phenanthroline). The resulting Mn-, MnLi-, and MnNa-compounds exhibit several unprecedented cage metallasilsesquioxane structural features, including intriguing self-assembly of silsesquioxane ligands. Complexes were tested for fungicidal activity against seven classes of phytopathogenic fungi.
View Article and Find Full Text PDFLanthanide-based silsesquioxanes constitute an emerging family of cage-like metallasilsesquioxanes with exciting optical and magnetic properties. We report here the synthesis, structures and luminescence properties of a series of tetranuclear lanthanide-silsesquioxane compounds of general formula [NEt][(PhSiO)(Ln/Ln')(NO)(EtOH)(MeCN)]·4(MeCN) with different lanthanide ions (where Ln/Ln' = Dy/Eu (1), Dy/Tb (2) and Eu/Tb/Y (3)) and investigate the impact of the lanthanide ions combination on magnetic and photo-luminescent properties. Compound 1 behaves as a field-induced Single Molecule Magnet (SMM) and presents temperature-dependent luminescence characteristics of Eu making it an emissive thermometer working in the temperature range 293-373 K with the maximum relative sensitivity of 1.
View Article and Find Full Text PDFA small family of nonanuclear CuCs-based phenylsilsesquioxanes - were prepared by a convenient self-assembly approach and characterized by X-ray diffraction studies. The compounds and show some unprecedented structural features such as the presence of a [PhSiO] silsesquioxane ligand and a CuCs nuclearity in which the metal cations occupy unusual positions within the cluster. Copper ions are "wrapped" into a silsesquioxane matrix, while cesium ions are located in external positions.
View Article and Find Full Text PDFA family of unusual octacopper cage methylsilsesquioxanes - were prepared and characterized. Features of their cagelike (prismatic) structure were established using X-ray diffraction studies. Effects of distortion of prismatic cages - due to variation of (i) additional alkaline metal ions (K, Rb, or Cs), (ii) combination of solvating ligands, and (iii) nature of encapsulating species were found.
View Article and Find Full Text PDFA series of phenylsilsesquioxane-benzoate heptacopper complexes - were synthesized and characterized by X-ray crystallography. Two parallel routes of toluene spontaneous oxidation (into benzyl alcohol and benzoate) assisted the formation of the cagelike structure . A unique multi-ligation of copper ions (from () silsesquioxane, () benzoate, () benzyl alcohol, () pyridine, () dimethyl-formamide and () water ligands) was found in .
View Article and Find Full Text PDFThe first examples of metallasilsesquioxane complexes, including ligands of the 8-hydroxyquinoline family -, were synthesized, and their structures were established by single crystal X-ray diffraction using synchrotron radiation. Compounds - tend to form a type of sandwich-like cage of CuM nuclearity (M = Li, Na, K). Each complex includes two cisoid pentameric silsesquioxane ligands and two 8-hydroxyquinoline ligands.
View Article and Find Full Text PDFThe present study describes a new feature in the self-assembly of cagelike copperphenylsilsesquioxanes: the strong influence of acetone solvates on cage structure formation. By this simple approach, a series of novel tetra-, hexa-, or nonacoppersilsesquioxanes were isolated and characterized. In addition, several new complexes of Cu or Cu nuclearity bearing additional nitrogen-based ligands (ethylenediamine, 2,2'-bipyridine, phenanthroline, bathophenanthroline, or neocuproine) were produced.
View Article and Find Full Text PDFNew luminescent cage-like tetranuclear silsesquioxanes [NEt][(PhSiO)(TbEu)(NO)(OH)(EtOH)(HO)]·4(EtOH) (1) and [NEt][(PhSiO)(TbEu)(NO)(EtOH)(MeCN)]·4(MeCN) (2) present a tunable thermosensitive Tb-to-Eu energy transfer driven by Tb and Eu emission and may be used as temperature sensors operating in the range 41-100 °C with excellent linearity ( = 0.9990) and repeatability (>95%). The thermometer performance was evidenced by the maximum relative sensitivity of 0.
View Article and Find Full Text PDFThis study reports intriguing features in the self-assembly of cage copper(II) silsesquioxanes in the presence of air. Despite the wide variation of solvates used, a series of prismatic hexanuclear Cu cages (-) were assembled under mild conditions. In turn, syntheses at higher temperatures are accompanied by side reactions, leading to the oxidation of solvates (methanol, 1-butanol, and tetrahydrofuran).
View Article and Find Full Text PDFInvited for the cover of this issue are Alexey N. Bilyachenko, Joulia Larionova and co-workers at the Russian Academy of Sciences, the Peoples' Friendship University of Russia, and University of Montpellier. The image depicts lanthanide-based cage-like silsesquioxanes exhibiting magnetic and luminescence properties that could constitute a particularly interesting new family related to multifunctional nanomaterials.
View Article and Find Full Text PDFThe synthesis, structure, magnetic, and luminescence properties investigations of four new cage-like lanthanide-based silsesquioxanes (Cat) [(PhSiO ) (LnO ) (O)(NO ) (EtOH) (MeCN) ] (where Cat =Et N , PPh P and Ln =Eu , Tb and (Ph P) [(PhSiO ) (TbO ) (O) (NO ) ]⋅10MeCN are reported. They present an unusual prism-like topology of cage architectures and lanthanide-characteristic emission, which makes them the first luminescent cage-like lanthanide silsesquioxanes. One of the Tb -based cages presents a magnetic spin-flip transition.
View Article and Find Full Text PDFAn unusual skeletal rearrangement of piperazine into ethylenediamine has been observed for the first time as a result of an attempt to synthesize a piperazine-linked metal-organic framework (MOF) using cage Cu(II),Na-phenylsilsequixane as a potential building block. Instead of the expected "metallasilsesquioxane-based MOF", a Cu complex coordinated both by silsesquioxane and ethylenediamine ligands was isolated. An effort to reproduce this result via direct interaction of Cu-phenylsilsequioxane and ethylenediamine surprisingly afforded two other types of complexes, copper-sodium and copper ionic products.
View Article and Find Full Text PDFA new "bicycle helmet"-like copper(ii),sodiumphenylsilsesquioxane Ph12Si12O12(OH)(O-)11Cu5Na(bipy)3(H2O) exhibited high catalytic efficiency in two homogeneous reactions: (i) functionalization of C-H compounds; (ii) formation of benzamides from alcohols.
View Article and Find Full Text PDFUnusual high-cluster (Cu) cage phenylsilsesquioxanes were obtained via complexation of in situ Cu,Na-silsesquioxane species formed with phenanthroline and neocuproine. In the first case, phenanthroline, acting as "a silent ligand" (not participating in the composition of the final product), favors the formation of an unprecedented cagelike phenylsilsesquioxane of CuNa nuclearity, 1. In the second case, neocuproine ligands withdraws two Cu ions from the metallasilsesquioxane matrix, producing two cationic fragments Cu(neocuproine).
View Article and Find Full Text PDFActa Crystallogr E Crystallogr Commun
March 2018
The title compound, CHFNO, is the product of a ring-expansion reaction from a seven-membered fluorinated hexa-hydro-azepine to a nine-membered azonine. The nine-membered azonine ring of the mol-ecule adopts a conformation. The C=C and C-N bond lengths [1.
View Article and Find Full Text PDFThe first Ni(ii)-based metallagermaniumsesquioxane cage compound [(PhGeO1.5)10(NiO)4(NaO0.5)2] presents a sandwich-like structure where two germsesquioxane cages are linked through an {NiO}4 core and exhibits slow dynamics of the magnetization.
View Article and Find Full Text PDFA new representative of an unusual family of metallagermaniumsesquioxanes, namely the heterometallic cagelike phenylgermsesquioxane (PhGeO)CuFe(O)OH(PhGe)O(bipy) (2), was synthesized and structurally characterized. Fe(III) ions of the complex are coordinated by oxa ligands: (i) cyclic (PhGeO) and acyclic (PhGeO) germoxanolates and (ii) O and (iii) HO moieties. In turn, Cu(II) ions are coordinated by both oxa (germoxanolates) and aza ligands (2,2'-bipyridines).
View Article and Find Full Text PDFThe synthesis, composition, and catalytic properties of a new family of hexanuclear Cu(II)-based phenylsilsesquioxanes are described here. Structural studies of 17 synthesized compounds revealed the general principle underlying their molecular topology: viz., a central metal oxide layer consisting of two Cu trimers is coordinated by two cyclic [PhSiO] siloxanolate ligands to form a skewed sandwich architecture with the composition [(PhSiO)(CuO)].
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