A new lithium chalcogenidotetrelate, denoted as LiChT phase, with the elemental combination Li/Sn/S was synthesized as solvent-free and solvent-containing salts. We present and discuss syntheses, crystal structures, spectroscopic and thermal properties of the phases, as well as the Li + ion conductivity of Li 4 SnS 4 , which is formally related to the thio-LISICON parent system Li 4 GeS 4 , and thus represents the first member of a new thiostannate-LISICON family. The solvent-free title compound shows a very promising Li + ion conductivity of 7 × 10 −5 S·cm −1 at 20°C and 3 × 10S·cm −1 at 100°C, which is exceptionally high for a ternary compound. Activation energies for the lithium ion transport measured via impedance spectroscopy (0.41 eV) correlate reasonably well with the values (0.29 to 0.33 eV) deduced from ionic mobility studies by 7 Li solid-state NMR spectroscopy. NMR two-time correlation functions suggest the occurrence of an additional, geometrically more restricted, ultraslow-motional process down to 121 K.

Li 8 (H 2 O) 29 ][Sn 10 O 4 S 20 ]·2H 2 O (1), which was obtained by an unusual synthesis pathway, represents the Li + salt of the supertetrahedral cluster anion [Sn 10 O 4 S 20 ] 8-. Due to the distinct hydration tendency of Li + , the crystal structure differs notably from that of a corresponding Cs + salt. Compound 1 extends the still very fragmentary

Monomeric N-heterocyclic carbene (NHC)-stabilized compounds (IMes)R 2 MP(H)SitBuPh 2 (2: M = Al, R = Et; 3: M = Ga, R = Et; 4: M = Ga, R = iPr; 5: M = In, R = Et) have been prepared in moderate yields through the cleavage of fourmembered metal phosphine rings like [iPr 2 GaP(H)SitBuPh 2 ] 2 (1) described herein. These compounds were isolated and characterized by means of X-ray crystallographic analysis as well as NMR spectroscopy. On this basis the structural properties, specifically the M-P bond lengths and C NHC -M-P

Four-membered Al/Ga-P ring systems were prepared by thermal hydrogen elimination between the primary silylphosphine H2PSitBuPh2 and the metal hydride precursors [(Me3N)MH3] (M = Al, Ga). The obtained cycles [(Me3N)HMP(SitBuPh2)]2 (M = Al: 1, Ga: 2) were functionalized by substituting the amine donor with the N-heterocyclic carbenes IPr and BImY to obtain the compounds [(NHC)HMP(SitBuPh2)]2 (IPr/Al: 3, BImY/Al: 4, IPr/Ga: 5, BImY/Ga: 6). All mentioned compounds feature an unusual external Lewis base stabilization as well as hydridic metal bound hydrogen atoms.

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Herein we present the synthesis and characterization of the new four-membered Ga/P cycle [tBuGaP(H)SitBuPh], which shows a cis/trans isomerization at ambient temperatures via a ring opening mechanism. The sterically demanding substituents on the phosphorus (-SitBuPh) and gallium (tBu) atoms lead to an unexpected reactivity towards bulky NHC ligands (IMes and IDipp). The resulting Lewis base stabilized monomeric 13/15 compounds feature an unusual binding mode of the carbene ligand. The ring opened state also enables a masked flp reactivity, which is shown by a reaction with the polar multiple bond in Ph-NCO.

Herein, the latest results on the topic of NHC-stabilized, monomeric group 13 metalsilylphosphanides, with the focus on the sterically demanding [GatBu 2 R x ]-fragment (x = 1, 2) are presented. The synthesis and characteristics of the cyclic compound [tBu 2 GaP(H)SitBuPh 2 ] 2 (1), followed by the cleavage of this cycle with different Lewis bases like pyridine, DMAP or the IiPr carbene is described for the first time. The compounds * Prof. Dr. C. von Hänisch

Synthesis and Crystal Structure of [Li 8 (H 2 O) 29 ][Sn 10 O 4 S 20 ]·2H 2 O. -The title compound is obtained in the attempt to prepare the tetrameric [Sn4S10] 4anion by acidification of an aqueous solution of Li4[SnS4] with HCl followed by slow evaporation of the solvent (pH 7 , argon stream, 80°C; 11% yield). [Li8 (H2O)29][Sn10O4S20]·2H2O crystallizes in the triclinic space group P1 with Z = 2 (single crystal XRD). The compound is the first salt of a supertetrahedral chalcogenidotetrelate anion with lithium counterions. Due to the distinct hydration tendency of Li + , the crystal structure differs notably from that of a corresponding Cs + salt. -(KAIB, T.; KAPITEIN, M.; DEHNEN*, S.; Z.