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By employing the chelate dicarbene 1, the new chlorogermyliumylidene complex 2 could be synthesized and isolated in 95% yield. Dechlorination of 2 with sodium naphthalenide furnishes the unique cyclic germadicarbene 3 which could be isolated in 45% yield. Compound 3 is the first isolable Ge(0) complex with a single germanium atom stabilized by a dicarbene. Its molecular structure is in accordance with DFT calculations which underline the peculiar electronic structure of 3 with two lone pairs of electrons at the Ge atom.

A merocyanine dye with an outstandingly large dipole moment of 14 Debye affords thin‐film transistors with 0.18 cm2V−1s−1 hole mobility and a 106 on/off ratio. These results suggest that molecules that lack symmetry and possess large dipole moments can perform excellent charge carrier transport contrary to established molecular semiconductor design strategies.

The first silicon analogue of a carbonic ester, compound 2, and the novel cyclodisiloxane 4 have been synthesized by remarkably clean mono- and dioxygenation reactions of the stable siloxysilylene 1 with N2O (CO2) and O2, respectively. Ester 2 represents a unique donor-supported SiO complex with an intriguing thermal stability up to 200 °C. The addition of MeOH at the SiO bond in 2 furnishes the corresponding adduct 3.

Organosilicon-phosphorus compounds are versatile building blocks in contemporary organophosphorus chemistry [1] and for the synthesis of metal phosphide semiconducting materials or respective molecular clusters. [2] Likewise, cyclic silicon-phosphorus compounds can serve as chelating electron-rich ligands in transitionmetal complexes, modeling unusual coordination modes of metal centers in catalysts.[3] The formation of siliconphosphorus compounds is commonly achieved by salt metathesis reactions using silicon halides and main-groupmetal phosphides (for example, lithium phosphides). [1, 4] However, the latter method is hardly suitable for the synthesis of strained silicon-phosphorus cycles and cages because of facile skeletal rearrangement reactions (for example, intermolecular ring enlargement) under the reaction conditions.[5] Hence, other synthetic methods are desirable to gain access to welldefined, strained silicon-phosphorus cycles and cages. A promising alternative strategy represents the utilization of unsaturated silicon compounds and white phosphorus (P 4 ) as shown by the gentle reaction of disilenes (R 2 Si=SiR 2 ) and phosphasilenes (R 2 Si=PR') with P 4 at 40 8C, leading to the unusual butterfly-shaped Si 2 P 2 and SiP 3 heterobicyclo-[1.1.0]butanes, [6a, 7] respectively. The mechanism of this remarkably mild P 4 activation and degradation process, initiated by low-valent silicon, is not clearly understood as yet.[6b] The latter results prompted us to investigate whether stable silylenes (R 2 SiD) are also capable of P 4 activation to give novel strained silicon-phosphorus cycles. Herein we report the first SiP 4 and Si 2 P 4 cage compounds which result from consecutive P 4 activation with the stable silylene 1 (Scheme 1).Although several stable silylenes have been described thus far, to our knowledge, both the highly electrophilic silylene (CH 2 ) 2 [C(SiMe 3 ) 2 ] 2 SiD [8] and the silicon analogues of nucleophilic Arduengo-type carbenes [9] seemed to be unsuitable for P 4 activation. In contrast, the zwitterionic silylene 1[10a] reacts gently with P 4 in the molar ratio of 1:1 at ambient temperature to give solely the compound 2. Remarkably, the germylene analogue of 1, [10b] in turn, is resistant towards P 4 even in boiling toluene owing to the lower reduction potential of Ge II versus Si II (inert-pair effect). Compound 2 can be isolated in the form of colorless crystals in 60 % yield. [11] According to EI-MS spectra and combustion analysis, 2 is a 1:1 adduct of 1 and P 4 . Its 1 H NMR spectrum proves the integrity of the C 3 N 2 chelate ligand at the silicon atom. As shown by 31 P NMR spectroscopy, 2 bears three chemically different sorts of 31 P nuclei (A, B, and X), giving rise to temperature-invariant resonance signals at d X = 131.9, d A = À342.4, and d B = À348.0 ppm. The low-field resonance signal at d X splits into a doublet of doublets ( 1 J(P X ,P A ) = 146.8, 1 J(P X ,P B ) = 144.7 Hz) while each of the two high-field signals exhibits a doublet of triplets ( 1 J(P X ,P A ) = 144....