Observation and Interpretation of Structural Variety in Alkaline Earth Metal Derivatives of Diphosphanyldisiloxane

Abstract

Alkaline earth metal derivatives of the diphosphanyldisiloxane O(SiiPr 2 PH 2 ) 2 (1) were obtained by reactions of 1 with MgBu 2 and M{N(SiMe 3 ) 2 } 2 (M = Ca, Sr, Ba), respectively. The metal complexes formed were characterised by elemental analysis, NMR spectroscopy, and IR spectroscopy as well as by single-crystal structure analysis. The solid-state structures depend on the metal ion involved. The magnesium derivative crystallizes from thf as a trimer and exhibits a six-mem-

Gas‐Phase Selective Oxidation of Benzyl Alcohol to Benzaldehyde with Molecular Oxygen over Unsupported Nanoporous Gold

“…Während die Metallierung des Diphosphanylsiloxans O{Si i Pr 2 PH 2 } 2 zur Ausbildung von Oligomeren mit polycyclischen, makrocyclischen oder polymeren Strukturen führt,1–3 konnte durch Einführung von je einem Ethylsubstituenten an den Phosphoratomen und anschließender Metallierung mit In i Pr 3 erstmals eine monomere Verbindung mit dem Diphosphanidsiloxan‐Liganden erhalten werden (Verbindung 5 ). Die analoge Verbindung mit “inversem“ Substituentenmuster –d.…”

Corrigendum: Synthesis and Conformational Analysis of Efrapeptins

“…The reactions of calcium, strontium and barium silazanide with the diarsanyldisiloxane mixture of 5 and 6 are fast and the products can be obtained as crystalline solids. Because the structures of compounds 7 – 10 are related to those of the previously published phosphanylsiloxane analogues,9 only the main differences between the arsenic‐ and phosphane‐siloxane‐based metal complexes are discussed in detail. All interatomic distances and angles for 7 – 10 are within the range of known similar compounds in the literature (see below).…”

“…Hydrogen atoms at the arsenic atoms are trans ‐orientated. The previously described diphosphanyldisiloxane analogue of the calcium salt [Ca(thf) 3 {(HPSi i Pr 2 ) 2 O}] 2 has a dimeric structure similar to that of 8 , as the result of the application of a different solvent (THF) 9. The Ca–As bond lengths in 7 [299.59(10) pm] are in the typical range for As–Ca bond lengths observed in other complexes, such as in [Ca(thf) 4 {As(SiMe 3 ) 2 } 2 ] described by Westerhausen et al [297.2(1)–301.7(1) pm] 13…”

“…Compound 1 was found to form complexes with several metal compounds, such as with the alkaline earth metals by use of the amides [M(thf) 2 {N(SiMe 3 ) 2 } 2 ] (for M = Ca, Sr, Ba) 9. Those complexes showed versatile and very different structural motifs, as is known for primary silylphosphanes and arsanes 12–16.…”

Stepwise Synthesis of Siloxane‐Substituted Oligophosphanes Pn[O(iPr2Si)2]2 (n = 2, 4)

“…This approach was recently used yielding multiple and versatile structures from difunctionalized phosphanylsiloxanes. [3] These compounds are useful starting compounds for the formation of different kinds of phosphane species through transmetalation reactions.…”