Pentasilatricyclo[2.1.0.0^2,5]pentane and Its Anion

Abstract

Kein Ferryl als Oxidans: Die Oxidation von Thiafettsäuren durch P450BM3 (CYP102A1) ist das Ergebnis der Oxidation durch eine Eisen(III)‐hydroperoxy‐Verbindung (Verb. 0) und nicht durch die erwartete Eisen(IV)‐Verbindung (Verb. 1). Das ist der erste Hinweis darauf, dass die Schwefeloxidation in einem P450‐Wildtyp über eine Hydroperoxystufe verläuft.

Spirobis(pentagerma[1.1.1]propellane): A Stable Tetraradicaloid

“…The only identifiable side products of this complex process, involving the breaking and making of many Si− Ge and Ge−Ge bonds, are the hydrosilane t Bu 2 MeSiH and the phenylsilane t Bu 2 MeSiPh, apparently formed by H abstraction and benzene (solvent) substitution reactions by the transient silyl radical t Bu 2 MeSi • . Both 1 H and 13 C NMR spectra of the cluster 1 are rather simple, displaying only one set of signals for all t Bu 2 MeSi substituents along with a resonance of the t Bu groups attached to the skeletal Si, and this spectral pattern agrees well with the high molecular symmetry of 1. As in the case of cage 2, the skeletal silicons in 1 are remarkably deshielded, being observed at +91.64 ppm.…”

“…In contrast to organic tricyclo[2.1.0.0 2,5 ]pentanes featuring exceedingly short bridgehead bonds, , their analogues containing the heavy group 14 elements showed a greater variation in the bridgehead-to-bridgehead bond length. Thus, a few examples of the stable tricyclo[2.1.0.0 2,5 ]pentane derivatives, fully (or partially) composed of heavy group 14 elements, can be categorized into two groups: (1) with normal bridging bond , or (2) with extraordinarily long bridging bond . Our cage 2 showed the structural features of the classical organic tricyclopentanes: a remarkably acute interplanar angle Ge1–Ge2–Ge4/Ge1–Ge2–Ge3 of 95.48(1)°, wide Si1–Ge1–Ge2 and Si2–Ge2–Ge1 bond angles of 136.099(17)° and 136.514(17)°, and, as a consequence, a squeezed Ge1–Ge2 bridge of 2.4535(3) Å, which is shorter than any other skeletal Ge–Ge bond in 2 [2.4718(3)–2.5020(3) Å, av.…”

“…In contrast to organic tricyclo[2.1.0.0 2,5 ]pentanes featuring exceedingly short bridgehead bonds, 1b,12 their analogues containing the heavy group 14 elements showed a greater variation in the bridgehead-to-bridgehead bond length. Thus, a few examples of the stable tricyclo[2.1.0.0 2,5 ]pentane derivatives, fully (or partially) composed of heavy group 14 elements, can be categorized into two groups: (1) with normal bridging bond 13,14 The photolysis of cage 2 in benzene solution (λ > 300 nm) resulted in the formation of a totally unexpected, albeit extraordinarily interesting product, Si 2 Ge 9 cluster 1 (Scheme 1 and Figure 2). For the moment, the mechanism for the formation of cluster 1 cannot be discussed in detail given the lack of any isolable (or even spectroscopically observable) reactive intermediates leading to the final 1.…”

Clusterization Effect on the29Si NMR Signal of a Spiro Silicon Atom

“…On the basis of a gauge-including atomic orbital (GIAO) calculation (vide infra), the signals at −145.2 and −108.5 ppm are assigned to the bridgehead and bridge silicon atoms of the bicyclo[1.1.0]­tetrasilane moiety, respectively. These signals are in the upfield region compared with those of 2 (−54.2 and −84.6 ppm) and are comparable to those of the related silyl-substituted compounds 4 (−145.1 and −90.6 ppm) and 5 (−182.3, −178.6, and −121.1 ppm) (Figure ). It is especially worth noting that the signal of the spiro silicon atom of 3 (104.2 ppm) is shifted to the downfield region by ca.…”

A High Yield Synthesis of an Octastannacubane and a Bis(silyl) Stannylene via Reductive Elimination of a Silane

“…Structural details are given in the Supporting Information. [17] Angewandte [28] and a structural isomer of pentastanna-[1.1.1]propellane previously reported by Sita and Bickerstaff. [10a] An alternative synthesis and X-ray crystallography characterization of 10 is presented in the SI.…”