The reactivity of the stable N-heterocyclic nitrenium salt 1,3-dimethyl-1,2,3-benzotriazolium iodide (1) toward various nucleophilic reagents has been investigated. Strongly nucleophilic reagents such as potassium hydride (KH), potassium cyclopentadienide (KCp), potassium tert-butoxide ((KOBu)-Bu-t), sodium methoxide (NaOMe), and sodium ethanethiolate (NaSEt) all reacted with 1 under demethylation and back-formation of 1-methyl-1,2,3-benzotriazole (2) in high isolated yield (ca. 80-90%). In marked contrast, an unusual phosphide addition reaction took place when 1 was treated with 1 equiv. of potassium diphenylphosphide (as the 1,4-dioxane adduct KPPh2(dioxane)(2)). In the course of this reaction the P atom replaces the central nitrogen of the triazole ring while being formally oxidized to an iminophosphorane derivative (3). Both compounds 2 and 3 have been structurally characterized through single-crystal X-ray diffraction.

The new organotin(IV) squarates and croconates [SnMe2(H2O)2]C4O4 (1), [SnMe3]2C4O4 (2), and [SnMe3(H2O)]2C5O5 (3), were prepared by salt metathesis from the appropriate sodium salts, and characterized by single‐crystal X‐ray diffraction and infrared spectroscopy. While 1 and 2 are coordination polymers with bridging C4O42– anions, compound 3 exists as a monomer in the solid state. In the hydrated compounds 1 and 3, the molecules are interconnected by various types of O–H···O bridges between non‐coordinated carbonyl oxygen atoms and water ligands, resulting in a supramolecular layer (1, 2) or network structure (3), respectively.

The first metallasilsesquioxanes comprising potassium and uranium have been synthesized and structurally characterized by single-crystal X-ray diffraction. (Cy7Si7O12)2K6(DME)4 (2; Cy = cyclohexyl) is a centrosymmetric dimer, in which the two silsesquioxide ligands are interconnected by μ3- and μ4-bridging siloxide moieties. (Cy7Si7O12)2UVI (3) represents the first metallasilsesquioxane complex of an actinide element, featuring a U atom that is coordinated by two tridentate silsesquioxide ligands in a distorted octahedral fashion. The different structural effects of the large metal atomic radii are discussed.

The reaction of 1,5-bis(trimethylsilyl)-1,3,5-trimethylbiuret with di- and monochlorophosphanes led, with formation of Me3SiCl, to the 1,3,5-trimethyl-1,3,5-triaza-2 sigma(3)lambda(3)-phosphorinan-4,6-diones 1-4 or to the 1,5-bis-(phosphano)-1,3,5-trimethylbiuret derivatives 5 and 6, respectively. Compounds 1, 2 and 4 were characterized by single-crystal X-ray diffraction studies. All the heterocycles were found to display a flattened boat configuration, with the phosphorus atom and the nitrogen atom opposite to it lying out of the plane. Oxidation of the sigma(3)lambda P-3 derivatives with urea/hydrogen peroxide 1:1 adduct furnished the corresponding 2-oxo-2 sigma(4)lambda(5)-phosphorinan-4,6-diones 8-11 and the 1,5-bis(phosphoryl)-biuret derivatives 12 and 13. Spirophosphoranes 15-22 were formed in the reaction of 1-4 with tetrachloro-o-benzoquinone and of 1, 3 and 4 with hexafluoroacetone. Compounds 20 and 21 featured an oxaphosphetane ring, which was stabilized by the electronegative CF3 groups. Compound 22 was formed through the loss of the trimethylsilyl group from 21. With the exception of 21, all oxaphosphetanes were characterized through their H-1, C-13, F-19 and P-31 NMR spectra, and through electron ionization mass spectrometry. For 20, a single-crystal X-ray structure study was conducted. The coordination at phosphorus in 20 was strongly distorted trigonal bipyramidal, with the oxetane ring attached to the phosphorus at one axial and one equatorial position. The reaction of 1 with 1-trifluoromethyl-2-(heptafluoroisopropyl)-biacetyl furnished the adduct 23, rather than an oxaphosphetane such as 20.

Zusammenfassung: Die Reaktion von 1,5-Bis(trimethylsilyl)-1,3,5-trimethylbiuret mit Di- bzw. Monochlorphosphanen führte unter Bildung von Me3SiCl zu den 1,3,5-Trimethyl-1,3,5-triaza-2σ 3 λ 3-phosphorinan-4,6-dionen 1–4 bzw. zu den 1,5-Bis(phosphano)-1,3,5-trimethylbiuret-Derivativen 5 und 6. Verbindungen 1, 2 und 4 wurden mittels Einkristall-Röntgenstrukturanalyse charakterisiert. Alle Heterozyklen wiesen eine flache Boot-Konfiguration auf, wobei das Phosphoratom und das gegenüberstehende Stickstoffatom außerhalb der Ebene der restlichen Atome lagen. Oxidation der σ 3 λ 3P-Derivative mit dem 1:1-Harnstoff/Wasserstoffperoxid-Addukt lieferte die entsprechenden 2-Oxo-2σ 4 λ 5-phosphorinan-4,6-dionen 8–11 und die 1,5-Bis(phosphoryl)biuret-Derivate 12 und 13. Die Spirophosphorane 15–22 wurden bei der Reaktion von 1–4 mit Tetrachlor-o-benzochinon, und von 1, 3und 4 mit Hexafluoraceton gebildet. Verbindungen 20 und 21 enthalten einen Oxaphosphetanring, der durch die elektronegativen CF3-Gruppen stabilisiert wird. Verbindung 22 wurde aus 21 durch Verlust der Trimethylsilylgruppe gebildet.Außer 21 wurden alle Oxaphosphetane über ihre 1H-, 13C-, 19F- und 31P-NMR-Spektren und mittels E.I.-Massenspektrometrie characterisiert. Auch für 20 wurde eine Einkristall-Röntgenstrukturanalyse durchgeführt; die Koordination am Phosphor ist stark verzerrt trigonal bipyramidal, wobei der Oxetanring eine axiale und eine equatoriale Lage am Phosphor besetzt. Die Reaktion von 1 mit 1-Trifluormethyl-2-(heptafluorisopropyl)-biacetyl lieferte 23 anstatt eines Oxaphosphetans wie 20.

The first triorganotin(IV) pentacyanopropenides, [R3Sn(H2O)(2)][C-3(CN)(5)] (R = Me (2), nBu (3), Ph (4) were prepared by treatment of Ag[C-3(CN)(5)] (1) with equimolar amounts of R3SnCl in reagent grade THF. In a similar manner, dark red [R3Sn(H2O)(2)][N{C(CN)C(CN)(2)}(2)] (6) containing the hexacyanoazapentadienyl anion was prepared in 55 % yield. The molecular structure of [Ph3Sn(H2O)(2)][C-3(CN)(5)] (4) was determined by X-ray diffraction. The crystal structure consists of separated trigonal-bipyramidal [Ph3Sn(H2O)(2)](+) cations and nearly planar [C-3(CN)(5)](-) anions which are linked through O-H center dot center dot center dot N hydrogen bonds to give a three-dimensional network.

The title compound, C(26)H(20)N(2), first reported in 1891, was obtained as a by-product in the preparation of benzildianil from benzil and excess aniline. The dihedral angles between the fused benzene ring and the pendant phenyl rings are 17.93 (11), 53.18 (10) and 89.08 (12)°.

The title compound, C(9)H(16)O(2), crystallizes with two mol-ecules in the asymmetric unit. The structure displays inter-molecular O-H⋯O hydrogen bonding.

Treatment of 9-(2-methoxyethyl)fluorene, C(13)H(9)CH(2)CH(2)OMe (1), with potassium hydride in THF/toluene in the presence of 18-crown-6 afforded orange-red crystalline K(18-crown-6)C(13)H(8)CH(2)CH(2)OMe ( 2) in 59% yield. A "constrained geometry"-type praseodymium complex containing the 9-(2-methoxyethyl)fluorenyl ligand, (COT)Pr(C(13)H(8)CH(2)CH(2)OMe)(THF) (3), was prepared by treatment of dimeric [(COT) Pr(mu-Cl)(THF)(2)](2) (COT = eta(8)-cyclooctatetraenyl) with in situ prepared KC(13)H(8)CH(2)CH(2)OMe. The molecular structures of 1, 2, and 3 were determined by single-crystal X-ray diffraction. (C) 2008 Elsevier B. V. All rights reserved.

The crystal structure of the title compound, CH2F4O2P2, is characterized by an extensive net of C—H⋯O hydrogen bonds.

The molecular structures of two N-pentafluorophenylcyclosilazoxanes have been investigated. X-Ray crystal structure determinations of (C6F5)(3)Me8Si4N3O (2) and (C6F5)(2)Me12Si6N2O4 (3) revealed the first structurally authenticated examples of eight-membered Si4N3O and twelve-membered Si6N2O4 ring systems.

The reaction of the title compound 1 with the p-R-aniline derivatives (R=H, F, OCH3, NO2, and NH2) led to the formation of the aza-2 sigma(3), 4 sigma(3)-diphosphetidines 2a-2e, whereas 2-trimethylsiloxyaniline furnished the azadiphosphetidine 2f. The reaction of the sterically crowded 2,6-dimethylaniline with 1 furnished the disubstituted derivative 3. The tricyclic compound 5 was formed during the reaction of 1,2-phenylenediamine with 1. Heptamethyldisilazane formed the aza-2 sigma(3), 4 sigma(3) diphosphetidine 6 on reaction with 1. The bulkier tert.-butylamine formed with 1 a mixture of the aza-2,4-diphosphetidine 7a and the disubstituted derivative 7b, which could not be separated. The reaction of 2b and 6 with tetrachloro-o-benzoquinone resulted in the formation of the bis-spirophosphoranes 8 and 9b, respectively. The formation of the monospirophosphorane 9a was observed in the P-31 NMR spectrum. The characterization of compounds is based in particular on NMR investigations (H-1, C-13, P-31). 2a was characterized by a single-crystal X-ray structure analysis. The dimethylurea fragment is planar; the four-membered ring is folded about the P center dot center dot center dot P vector by 38.7 degrees.

A novel approach for the synthesis of cis/trans-fused perhydroazulenes 13-19 is reported. The stereochemistry of the derivatives of carbene addition products 9a-c/20-22, of the 2,6-disubstituted perhydroazulenes 12a-c/23-25, and that of compounds 26-27 has been studied by single-crystal X-ray crystallography. The hydrogenation of the tropylidene to the perhydroazulene skeleton under various conditions is described. (C) Wiley-VCH Verlag GmbH & Co.

The reaction of (eta(5)-C5H5)Mo(CO)(3)(-) with p-CH3C6H4S(O)(2)O(CH2)(3)C6H5 produces (eta(5)-C5H5)(OC)(3)Mo(CH2)(3)C6H5. This is only the second structurally characterized organometallic species in which an aromatic moiety is separated by three or more methylene groups. The alkyl chain adopts a staggered conformation, the Mo-C(1)-C(2)-C(3)-C(4) unit is nearly coplanar, and the alkyl chain eclipses the trans-carbonyl group on Mo. NMR evidence indicates that this conformation is preserved in solution. (c) 2006 Elsevier B.V. All rights reserved.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The three (O-methyl)-p-ethoxyphenyldithiophosphonato triphenylphosphine complexes of copper, silver and gold, [(Ph3P)(n)M {S2P(OMe)C6H4OEt-p}] (M=Cu, n=2; M=Ag, Au, n=1) investigated structurally by X-ray diffraction exhibit remarkable structural differences. The copper compound is a four-coordinate chelate monomer with Cu-S 2.4417(6) and 2.5048(6) angstrom; P-Cu-S 104.24(2)-114.01(2)degrees; Cu-S-P 82.49(3)degrees and 80.85(2)degrees. The silver compound is a cyclic dimer with bridging dithiophosphonato ligands and three-coordinate silver atoms [Ag-S 2.5371(5) and 2.6867(5) angstrom; P-Ag-S 122.88(2)degrees and 122.17(2)degrees; Ag-S-P 89.32(2)degrees and 103.56(2)degrees]. The gold compound is monomeric with linear dicoordinate gold [Au-S 2.3218(6) angstrom; P-Au-S 177.72(2)degrees, Au-S-P 100.97(3)degrees].

The synthesis of [2.2]paracyclophane/dehydro[14]annulene hybrids 1 and 2 is reported. Comparison of the proton NMR spectra of 1 and 2 with their open precursors and with related model compounds reveals the pronounced effect of macrocycle formation upon the cyclophane protons H15/H16, which lie above the shielding cone of the diatropic [14]annulene moiety. [structure: see text]

The reaction of Ln(NO3)(3) (Ln = Ce, Tb, or Yb) with Ph2PCH2CH2P(O)Ph-2 in various molar ratios produces Ln(NO3)(3)(OPPh2CH2CH2PPh2)(3). X-ray powder diffraction demonstrates that the three compounds are isostructural. Single crystal X-ray diffraction structures were obtained for Ln = Cc and Tb. The compound are isomorphous and crystallize in the trigonal R3c space group. The lanthanide ions are nine-coordinate with three bidentate nitrate ions and three (OPPh,CH2CH2PPh2) ligands coordinated through oxygen. If the coordination sphere is defined by the three lanthanide-nitrogen vectors and the three lanthanide-O(P) bonds, the complexes can be described as facial octahedral. The chemistry of the Ph2P-CH2CH2-P(O)Ph-2 - Ln(NO3)(3) system appears to be simpler than ones involving simple phosphine oxide ligands.

Angewandte Chemie International EditionVolume 43, Issue 35 p. 4603-4606 Communication Fully Metalated Silsesquioxanes: Building Blocks for the Construction of Catalyst Models† Volker Lorenz Dr., Volker Lorenz Dr. Chemisches Institut, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany, Fax: (+49) 391-671-2933Search for more papers by this authorStephan Gießmann Dr., Stephan Gießmann Dr. Chemisches Institut, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany, Fax: (+49) 391-671-2933Search for more papers by this authorYurii K. Gun'ko Dr., Yurii K. Gun'ko Dr. Department of Chemistry, Trinity College, Dublin 2, IrelandSearch for more papers by this authorAxel K. Fischer Dr., Axel K. Fischer Dr. Chemisches Institut, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany, Fax: (+49) 391-671-2933Search for more papers by this authorJohn W. Gilje Prof. Dr., John W. Gilje Prof. Dr. Chemistry Department, James Madison University, Harrisonburg, VA 22807, USASearch for more papers by this authorFrank T. Edelmann Prof., Frank T. Edelmann Prof. [email protected] Chemisches Institut, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany, Fax: (+49) 391-671-2933Search for more papers by this author Volker Lorenz Dr., Volker Lorenz Dr. Chemisches Institut, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany, Fax: (+49) 391-671-2933Search for more papers by this authorStephan Gießmann Dr., Stephan Gießmann Dr. Chemisches Institut, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany, Fax: (+49) 391-671-2933Search for more papers by this authorYurii K. Gun'ko Dr., Yurii K. Gun'ko Dr. Department of Chemistry, Trinity College, Dublin 2, IrelandSearch for more papers by this authorAxel K. Fischer Dr., Axel K. Fischer Dr. Chemisches Institut, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany, Fax: (+49) 391-671-2933Search for more papers by this authorJohn W. Gilje Prof. Dr., John W. Gilje Prof. Dr. Chemistry Department, James Madison University, Harrisonburg, VA 22807, USASearch for more papers by this authorFrank T. Edelmann Prof., Frank T. Edelmann Prof. [email protected] Chemisches Institut, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany, Fax: (+49) 391-671-2933Search for more papers by this author First published: 01 September 2004 https://doi.org/10.1002/anie.200454094Citations: 42 † This work was supported by the Deutsche Forschungsgemeinschaft (Schwerpunktprogramm "Spezifische Phänomene der Silicium-Chemie"), the Fonds der Chemischen Industrie, and the European Commission (contract G1RD-CT-1999-00167 "SAFEGAS"). Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Graphical Abstract Versatile building blocks for the construction of molecular models for heterogeneous catalysts are readily available in high yields in the form of fully metalated silsesquioxane derivatives, such as dimeric 1, by using alkali-metal silylamides as deprotonating agents. Citing Literature Volume43, Issue35September 6, 2004Pages 4603-4606 RelatedInformation

The crystal structure of nickel (II)di(methoxyethylxanthato)-bis(pyridine) adduct (1), Ni(S2COCH2CH2OCH3)(2).2C(5)H(5)N, has been solved by single crystal X-ray diffraction. The compound is a cis-octahdral complex. In the crystal the molecules of (1) are self-assembled through weak C-H...O hydrogen bonds to form chain-like arrays, further associated in a 3D architecture.