The use of HSiMe2OSiMe2H (1) and various hydrodisilanes, R3SiSiMe2H (2; R = alkyl, aryl), as reductants for N,N-dimethylformamide (DMF) in the presence of (Me3N)Mo(CO)5 as a catalyst led to the formation of a series of novel and structurally interesting siloxanes as well as trimethylamine. In the case of 1 the cyclic poly(dimethylsiloxanes) D 4 and D 6 are obtained, and for 2 the products are bis(disilyl) ethers, (R3SiSiMe2)2O. Siloxymethylamine intermediates resulting from an initial hydrosilylation of DMF, (Me2NCH2OSiMe2)2O (3) and R3SiSiMe2OCH2NMe2 (4; R = Me, Ph), from the reactions of 1 and 2, respectively, can be observed and, in the case of 3, isolated and purified. In the presence of the respective starting silanes and the catalyst the intermediates readily react to form the appropriate siloxane materials and trimethylamine. Compound 3 was functionalized by reaction with R3ECl (E = Si, Ge, R = Me, Ph) to provide group 14 containing products (R3EOSiMe2)2O (R = Me, E = Si (5a), Ge (6a); R = Ph, E = Si (5b), Ge (6b)). Reactions of Me3SiSiMe2OCH2NMe2 (4a) with R3ECl produced Me3SiSiMe2OER3 (R = Me, E = Si (7), R = Ph, E = Ge, 8). The crystal structure of (Ph3SiSiMe2)2O (9c) is reported and exhibits an Si–O–Si angle of 165° and the longest Si–Si bond length (2.376(2) Å) for such bis(disilyl) ethers. The new (Ph3EOSiMe2)2O derivatives 5b and 6b have been structurally characterized and exhibit distinct conformations about the central SiOSi fragment. In the case of the Ph3Si compound 5b the dihedral angle between the two end groups is 180° with completely staggered SiMe groups on the central Si atoms, whereas for the Ge congener it is 55.7° and the structure exhibits eclipsed SiMe groups. The distinction seems to be due to both intra- and intermolecular phenyl group π stacking in 6b stabilizing this formally higher energy conformation.

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Tetramethylsilane was decomposed in the microwave discharge flow of Ar to produce emission spectra of the CH(A 2 X 2 ) and Si(4s3p) transitions. The mechanisms of the production of the excited states were studied by the combined analysis of the laser-induced fluorescence (LIF) spectroscopy of the 3 P 0 metastable state of Ar and electrostatic-probe measurements. The pressure of Ar was varied in the range of 0.2-0.4 Torr; the density of Ar( 3 P 0 ), n M , and the density, n e , and temperature, T e , of free electrons were varied. By comparing the Ar-pressure dependencies of the emission intensities, n M , n e , and T e with the support of a kinetic analysis, the production processes of CH(A 2 ) and Si(4s) states were found predominantly to be the energy transfer from the metastable state of Ar atoms.

We propose a novel structure for optical assembly that enables high-precision passive alignment assembly process for our flexible printed circuit-based optical engine. The optical engines are fabricated with less than 7 ȝm of misalignment between optical devices and polymer waveguides. This high-precision alignment suppresses the optical coupling losses to an average of 2.9 dB for the transmitter side and, 1.6 dB for the receiver side. The optical engines are installed to a high-volume product of 100 Gb/s quad small form-factor pluggable (QSFP) optical transceivers. The QSFP demonstrated clear eye opening and error-free operation at 100Gb/s with high yield rate thanks to the low-coupling loss resulting from the high-precision alignment of optical devices.