[4-(Di-tert-butyl­fluoro­silan­yl)phenyl]methanol

The asymmetric unit of the title compound, C15H25FOSi, contains two independent mol­ecules. Each of the Si atoms approximates the expected tetra­hedral geometry with Si—F bond lengths of 1.6128 (11) and 1.6068 (11) Å in the two independent mol­ecules. In the crystal, supra­molecular chains along a are found mediated by O—H⋯O hydrogen bonds

τBu₂SiF-Derivatized D₂-Receptor Ligands: The First SiFA-Containing Small Molecule Radiotracers for Target-Specific PET-Imaging

The synthesis, radiolabeling and in vitro evaluation of new silicon-fluoride acceptor (SiFA) derivatized D-2-receptor ligands is reported. The SiFA-technology simplifies the introduction of fluorine-18 into target specific biomolecules for Positron-Emission-Tomography (PET). However, one of the remaining challenges, especially for small molecules such as receptor-ligands, is the bulkiness of the SiFA-moiety. We therefore synthesized four Fallypride SiFA-conjugates derivatized either directly at the benzoic acid ring system (SiFA-DMFP, SiFA-FP, SiFA-DDMFP) or at the butyl-side chain (SiFA-M-FP) and tested their receptor affinities. We found D2-receptor affinities for all compounds in the nanomolar range (Ki(SiFA-DMFP) = 13.6 nM, Ki(SiFA-FP) = 33.0 nM, Ki(SiFA-DDMFP) = 62.7 nM and Ki(SiFA-M-FP) = 4.21 nM). The radiofluorination showed highest yields when 10 nmol of the precursors were reacted with F-18]fluoride/TBAHCO(3) in acetonitrile. After a reversed phased cartridge purification the desired products could be isolated as an injectable solution after only 10 min synthesis time with radiochemical yields (RCY) of more than 40% in the case of SiFA-DMFP resulting in specific activities >41 GBq/mu mol (>1,100 Ci/mmol). Furthermore, the radiolabeled products were shown to be stable in the injectable solutions, as well as in human plasma, for at least 90 min

Design of a Cooper pair box electrometer for application to solid-state and astroparticle physics

We describe the design and principle of operation of a fast and sensitive electrometer operated at millikelvin temperatures, which aims at replacing conventional semiconducting charge amplifiers in experiments needing low back-action or high sensitivity. The electrometer consists of a Cooper Pair box (CPB) coupled to a microwave resonator, which converts charge variations to resonance frequency shifts. We analyze the dependence of the sensitivity on the various parameters of the device, and derive their optimization. By exploiting the nonlinearities of this electrometer, and using conventional nanofabrication and measurement techniques, a charge sensitivity of a few $10^{- 7} e / \sqrt{Hz}$ can be achieved which outperforms existing single charge electrometers.Comment: 13 pages, 7 figure

Bis{decacarbonylbis[mu-2,2 `-(phenylimino)diethanolato]ditin(II)ditungsten(0)(2 Sn-W)} hexacarbonyltungsten(0)

In the title 2:1 adduct, [Sn(2)W(2)(C(10)H(13)NO(2))(2)(CO)(10)](2)[W(CO)(6)], the complete hexacarbonyltungsten molecule is generated by a crystallographic inversion centre. The heterometallic molecule features a central Sn(2)O(2) core with essentially equal Sn-O(ethoxy) bond lengths. The second ethoxy O and amine N atoms of each N,O,O'-tridentate ligand coordinate to one Sn atom only. The NO(3) donor atoms occupy basal positions and the W atom the apical position in a distorted square-pyramidal geometry for each Sn atom. The W atoms are approximately syn to each other but the central metal core is non-planar [W-Sn center dot center dot center dot Sn-W pseudo-torsion angle = 43.573 (16)degrees]. One of the carbonyl ligands in the heterometallic molecule is disordered over two orientations with equal occupancies. In the crystal, the heterometallic molecules associate via C-H center dot center dot center dot O interactions, forming supramolecular layers with undulating topology in the ab plane. These stack along the c axis, defining voids which are occupied by the W(CO)(6) molecules

Development of an Alkyne Analogue of the de Mayo Reaction: Synthesis of Medium‐Sized Carbacycles and Cyclohepta[ b

Embedded medium-sized carbacycles and cyclohepta [b] indoles occur frequently as scaffold elements in natural products and bioactive compounds. Described herein is a conceptionally novel photochemically triggered cascade process to these scaffolds. Key to the cascading ring-expansion process is an unprecedented intramolecular alkyne analogue of the de Mayo reaction

Progress toward the Total Synthesis of Gukulenin A: Photochemically Triggered Two-Carbon Ring Expansion Key to α‑Tropolonic Ether Synthesis

The ex-chiral-pool synthesis of an advanced gukulenin A precursor from (−)-piperitone is revealed. Key C/C connecting maneuvers to the synthesis of a C₂ dissymmetric bis­(α-tropolonic) ether building block are a ring-contracting Meinwald rearrangement, a photochemically triggered two-carbon ring expansion, and a homodimerization by cross-metathesis