Search

The carbonyl cluster compound [GeRu6(CO)18HI] is unique in regard to its structure and bonding with a GeRu6 cluster core, a planar GeRu4HI unit, extensive multi‐center bonding, and an aromatic ring current similar to benzene (9‐10 nA T−1). The open‐shell cluster core is a Ge‐centered five‐membered Ru4(Ru2) ring with CO ligands and an additional H and I atom, each bridging two Ru atoms on opposite sides of the cluster core. The compound is prepared at 130 °C in a weakly‐coordinating ionic liquid. [ABSTRACT FROM AUTHOR]

Copyright of Angewandte Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We report on the synthesis and characterization of a series of (mostly) air‐stable diorganyl bis(pyridylimino) isoindolide (BPI) aluminum complexes and their chemistry upon visible‐light excitation. The redox non‐innocent BPI pincer ligand allows for efficient charge transfer homolytic processes of the title compounds. This makes them a universal platform for the generation of carbon‐centered radicals. The photo‐induced homolytic cleavage of the Al−C bonds was investigated by means of stationary and transient UV/Vis spectroscopy, spin trapping experiments, as well as EPR and NMR spectroscopy. The experimental findings were supported by quantum chemical calculations. Reactivity studies enabled the utilization of the aluminum complexes as reactants in tin‐free Giese‐type reactions and carbonyl alkylations under ambient conditions, which both indicated radical‐polar crossover behavior. A deeper understanding of the physical fundamentals and photochemical process was provided, furnishing in turn a new strategy to control the reactivity of bench‐stable aluminum organometallics. [ABSTRACT FROM AUTHOR]

Herein, we report the synthesis of a novel ferrocenyl‐functionalized bis(phosphinimino)methane ligand (CH2(PPh2NFc)2). Deprotonation of CH2(PPh2NFc)2 with KN(SiMe3)2 gave the dimeric species [K{CH(PPh2NFc)2}]2, which was further reacted with ECl2 (E=Ge, Sn) to yield the tetrylene compounds [{CH(PPh2NFc)2}ECl]. The ligand and the resulting tetrylenes were examined for their electrochemical properties with the aid of cyclic voltammetry. Furthermore, the reaction of the tetrylenes [{CH(PPh2NFc)2}ECl] with [AuC6F5(tht)] resulted in the bimetallic complexes [{(AuC6F5)CH(PPh2NFc)2}ECl] with an unusual Au coordination on the ligand backbone. [ABSTRACT FROM AUTHOR]

We report on so‐called "hidden FLPs" (FLP: frustrated Lewis pair) consisting of a phosphorus ylide featuring a group 13 fragment in the ortho position of a phenyl ring scaffold to form five‐membered ring structures. Although the formation of the Lewis acid/base adducts was observed in the solid state, most of the title compounds readily react with carbon dioxide to provide stable insertion products. Strikingly, 0.3–3.0 mol% of the reported aluminum and gallium/carbon‐based ambiphiles catalyze the reduction of CO2 to methanol with satisfactory high selectivity and yields using pinacol borane as stoichiometric reduction equivalent. Comprehensive computational studies provided valuable mechanistic insights and shed more light on activity differences. [ABSTRACT FROM AUTHOR]

We report the isolation and characterization of an unknown reaction product from the reaction of AlBr3 with three equivalents of t‐BuLi. The polymeric and solvent‐free lithium alanate {Li[t‐Bu2AlH2]}n was characterized by X‐ray structure analysis, NMR and IR spectroscopy. The title compound was found to be a suitable starting material for the synthesis of [t‐Bu2AlH]3 by reacting it with readily available [t‐Bu2AlBr]2. [ABSTRACT FROM AUTHOR]

The synthesis of three novel imidazolyl‐substituted sulfur‐containing heteroacenes is reported. These heteroacenes consisting of annelated benzo‐ and naphthothiophenes serve as precursors for the generation of open‐shell quinoid heteroacenes by oxidation with alkaline ferric cyanide. Spectroscopic and computational experiments support the formation of reactive open‐shell quinoids, which, however, quickly produce paramagnetic polymeric material. [ABSTRACT FROM AUTHOR]

The rare earth element complexes (Ln=Y, La, Sm, Lu, Ce) of several podant κ6N‐coordinating ligands have been synthetized and thoroughly characterized. The structural properties of the complexes have been investigated by X‐ray diffraction in the solid state and by advanced NMR methods in solution. To estimate the donor capabilities of the presented ligands, an experimental comparison study has been conducted by cyclic voltammetry as well as absorption experiments using the cerium complexes and by analyzing 89Y NMR chemical shifts of the different yttrium complexes. In order to obtain a complete and detailed picture, all experiments were corroborated by state‐of‐the‐art quantum chemical calculations. Finally, coordination competition studies have been carried out by means of 1H and 31P NMR spectroscopy to investigate the correlation with donor properties and selectivity. [ABSTRACT FROM AUTHOR]

The heteronuclear [1.1.1]propellane [Sn.sub.2][Si.sub.3][Mes.sub.6] (1; Mes = 2,4,6-[Me.sub.3][C.sub.6][H.sub.2]) was reacted with the dichalcogenyl compounds PhE-EPh (E = S, Se, or Te) to furnish the 1,3-bis(organochalcogenyl) distannatrisilabicyclo[1.1.1]pentanes 3 (E = S), 4 (E = Se), and 5 (E = Te). The E-E bond addition reaction is reminiscent of the formation of FcS-Sn[(Si[Mes.sub.2]).sub.3]Sn-SFc (2; Fc = ferrocenyl) reported previously. Contrary to 2, for which it was shown that its formation can be enhanced by daylight, the analogous clusters 3-5 are very sensitive to light in solution. Solid samples are, however, stable for a prolonged period of time. All three compounds were characterized in detail, including X-ray structure analyses on single crystals of 3 and 5. The core structure connectivities of the clusters were fully confirmed by [sup.119]Sn, [sup.77]Se, and [sup.125]Te NMR spectroscopy, among others. In particular, the [sup.117]Sn-[sup.119]Sn coupling constant between the formally nonbonded bridgehead tin atoms nicely correlates with the interbridgehead distance, i.e., a larger distance is associated with a smaller [sup.117]Sn-[sup.119]Sn coupling constant, and vice versa. This coupling is mediated by so-called 'back-lobe-to-back-lobe' interactions through cage. The detection of two different [sup.77]Se-[sup.119]Sn and [sup.125]Te-[sup.119]Sn couplings each (i.e., ¹J and ²J) further supported these findings. Key words: tin, silicon, chalcogenes, [1.1.1]propellane, bicyclopentane. Le [1.1.1]propellane heteronucleaire [Sn.sub.2][Si.sub.3][Mes.sub.6] (1; Mes = 2,4,6-[Me.sub.3][C.sub.6][H.sub.2]) reagit avec les dichalcogenes PhE-EPh (E = S, Se, ou Te) pour donner le 1,3-bis(organochalcogenyl) distannatrisilabicyclo[1.1.1]pentanes 3 (E = S), 4 (E = Se), et 5 (E = Te). La reaction d'addition de la liaison E-E rappelle la formation de FcS-Sn[(Si[Mes.sub.2]).sub.3]Sn-SFc (2; Fc = ferrocenyl) signale precedemment. Contrairement a 2, pour lequel il a ete montre qu'une exposition a la lumiere du jour accroit sa formation, les clusters analogues 3-5 sont tres sensibles a la lumiere en solution. Par contre, les echantillons solides sont stables sur une longue periode. Chacun des trois composes ont ete caracterises en detail, analyses de structures aux rayons X sur monocristaux comprises pour les composes 3 et 5. Les connexions de la structure centrale des clusters ont ete pleinement confirmees entre autres par spectroscopie RMN du [sup.119]Sn, du [sup.77]Se et du [sup.125]Te. En particulier, la constante de couplage [sup.117]Sn-[sup.119]Sn entre les atomes d'etain en tete de pont, entre lesquels il n'y a formellement aucune liaison, est bien correlee a la distance entre les tetes de ponts, c'est-a-dire que plus la distance est grande, plus la constante de couplage [sup.117]Sn-[sup.119]Sn associee est petite et vice versa. Cette derniere est transmise par des interactions dites 'de lobe arriere a lobe arriere' a travers la cage. La detection pour chacun de deux couplages [sup.77]Se-[sup.119]Sn et [sup.125]Te-[sup.119]Sn (c'est-a-dire J et ²J) vient etayer ces decouvertes. Mots-cles: etain, silicium, chalcogenes, [1.1.1]propellane, bicyclopentane., Introduction Heavy-core propellanes of group 14 of the general formula [E.sub.5][Ar.sub.6] (E = Si, Ge, or Sn; Ar = aryl), (1) have continuously attracted great interest, not only because they [...]

A comparison of the ligand substitution behavior of [ReBr(sub3)(CO)(sub3)](NEt(sub4)(sub2) and [ReBr(sub3)(CO)(sub2)(NO)NEt(sub4) in aqueous media is done. The products of the substitution reactions are isolated and characterized by means of IR, NMR, MS, and X-ray structure analysis.