Ulrich Zenneck

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Computational studies on a series of polyphospholyl-substituted N-heterocyclic phosphines (CH)(2)(NR)(2) P-P(n)(CH)(5-n) (R=Me, n=1-5) disclosed that increasing formal replacement of CH units in the phosphole ring by phosphorus atoms is associated with an increase in P-P distances and charge separation, and a decrease in covalent bond orders. Altogether,(More)
On the basis of isolated diastereomeric triorganylstannyl-P5 -deltacyclenes 7' and 7'', almost pure enantiomers of their destannylation products 8' and 8'' are now available. These stereochemically inert cage chiral species contain a configurationally labile P1H1 group that defines two epimers 8 a and 8 b of each of the enantiomers, which are connected by(More)
Cage-chiral tetra-tert-butyl-P5-deltacyclene is accessible as a pair of highly enriched enantiomers and . The only secondary phosphorus atom P1 of the cage can be selectively oxidized by reaction with t-BuOOH. The P1-oxo species and , allow the direct determination of their ee values. Oxidation occurs with the complete retention of the optical activity of(More)
An effective cyclic addition reaction of diastereomeric (R*)diphenyltin-3,5-di(tert-butyl)-1,2,4-triphosphole derivatives 6 a-c (R* = (-)-cis-myrtanyl (a), (-)-trans-myrtanyl (b), m-(2-bornyl-2-ene)phenyl (c) with two equivalents of tert-butylphosphaalkyne 1 leads to 1:1 mixtures of diastereomeric stannylated pentaphosphadeltacyclene derivatives 7 a-c with(More)
Photolysis of [Cp*As{W(CO)(5)}(2)] (1a) in the presence of Mes*P=PMes* (Mes*=2,4,6-tri-tert-butylphenyl) leads to the novel 1,3-diphospha-2-arsaallyl radical [(CO)(5)W(mu,eta(2):eta(1)-P(2)AsMes*(2))W(CO)(4)] (2a). The frontier orbitals of the radical 2a are indicative of a stable pi-allylic system that is only marginally influenced by the d orbitals of the(More)
Several independent synthetic routes are described leading to the formation of a novel unsaturated tetracyclic phosphorus carbon cage compound tBu4C4P6 (1), which undergoes a light-induced valence isomerization to produce the first hexaphosphapentaprismane cage tBu4C4P6 (2). A second unsaturated isomer tBu4C4P6 (9) of 1 and the bis-[W(CO)5] complex 13 of 1(More)
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