Bis[3,4,5,6-tetrabrom-1,2-benzoldiolato(2-)]-(pyrrolidiniomethyl)silicat-Acetonitril-Solvat [(C6Br4O2)2SiCH2(H)NC4H8 · CH3CN]: Synthese sowie Kristall- und Molekülstruktur eines zwitterionischen [lambda]5-Spirosilicats

Single crystal X-ray studies on bis[3,4,5,6-tetrabromo-1 ,2-benzenediolato(2- )](pyrrolidiniomethyl)silicate acetonitrile solvate [(C6Br40 2hSiCH2(H)NC4H8 · CH3CN; monoclinic, P2t/c, a = 808.5(4), b = 1533.0(8), c = 2212.6(1) pm, ß = 97.67(2)0 , Z = 4] revealed a zwitterionic structure with a pentacoordinate, formally negatively charged silicon atom and a positively charged ammonium moiety. The silicon atom is surrounded by four oxygen atoms and one carbon atom in a trigonalbipyramidal fashion, with the carbon atom in an equatorial position. The structure is displaced by 7.0% from the trigonal bipyramid towards the square pyramid. The zwitterion and the CH3CN molecule form intermolecular N-H · · · N hydrogen bonds

Reactions of (-)-sparteine with alkali metal HMDS complexes : conventional meets the unconventional

Conventional (-)-sparteine adducts of lithium and sodium 1,1,1,3,3,3-hexamethyldisilazide (HMDS) were prepared and characterised, along with an unexpected and unconventional hydroxyl-incorporated sodium sodiate, [(-)-sparteine·Na(-HMDS)Na·(-)-sparteine]+[Na4(-HMDS)4(OH)]--the complex anion of which is the first inverse crown ether anion

(1R,2R)-N,N′-Dimethyl­cyclo­hexane-1,2-diamine

The molecule of the title compound, C8H18N2, possesses C 2 symmetry. Owing to its stereochemistry, it is used in the synthesis of chiral ligands and metal complexes for asymmetric synthesis. The cyclo­hexane ring shows a chair conformation with the amino groups in equatorial positions. Contrary to the literature, the title compound is not a liquid, but a crystalline solid at room temperature (293 K). The absolute configuration is assigned from the synthesis

(1R,2R)-N,N′-Diisobutyl-N,N′-dimethyl­cyclo­hexane-1,2-diamine

The title compound, C16H34N2, is a chiral diamine with fixed R configuration at both stereogenic carbon centres of the cyclo­hexane backbone. Due to their different substituents, the two N atoms also become stereogenic. In the crystal structure, the configuration at one of the two nitro­gen centres is fixed, with the free electron pair pointing inward and the isobutyl group in a trans position towards the cyclo­hexane backbone resulting in an R configuration. The isobutyl group at the second N atom, however, is disordered with 75% S configuration and 25% R configuration. In both cases, the isobutyl group is arranged in a trans position towards the cyclo­hexane backbone

(S)-1,2-Dimethyl-1,1,2-triphenyl-2-(4-piperidiniometh­yl)disilane chloride

The title compound, C26H34NSi2 +·Cl−, shows chirality at silicon. Because of its highly selective synthesis with an e.r. of >99:1 by means of a racemic resolution with mandelic acid, the free disilane is of great importance to the chemistry of highly enanti­omerically enriched lithio­silanes and their trapping products. N—H⋯Cl hydrogen bonding is present between the protonated nitro­gen atom of the piperidino group and the chloride counter-anion. The silicon–silicon distance as well as silicon–carbon and carbon–nitro­gen bond lengths are in the same ranges as in other quaternary, functionalized di- and tetra­silanes

Syntheses, Structures, and Photophysical Properties of Mono- and Dinuclear Sulfur-Rich Gold(I) Complexes

Sulfur-rich 1,2 dithiolene and neutral thione ligands were used for the synthesis of gold complexes, some of them exhibiting aurophilic interactions. Surprisingly, the closest Au···Au contact is observed in an unsupported dinuclear complex, which makes part of a supramolecular network. Photophysical studies, combined with DFT calculations, indicate that the participations of the Au···Au interactions have some relevance to the rich luminescence properties of these compounds

Dibromido[(tert-butyl­amino)dimeth­yl(piperidin-1-ylmeth­yl)silane-κ2 N,N′]zinc(II)

The title compound, [ZnBr2(C12H28N2Si)], is an example of a neutral coordination compound of a bidentate ligand to a metal centre with the Zn atom being coordinated by two Br and two N atoms, yielding a slightly distorted tetra­hedral coordination environment

Influence of lithium coordinating additives on the structure of phenyldimethylsilyllithium

The synthesis and structural investigation of two dimethylphenylsilyllithium adducts with coordinating nitrogen donors quinuclidine and 1,3,5-tri-tert-butylhexahydro-1,3,5-triazine (tbtac) are presented. The structures show a comparatively long Si−Li distance and one amongst the shortest in monomeric silyllithiums reported so far, respectively. The structural investigations shed light on the influence of the donating additive for the lithium center on the structure of silyllithium compounds