Synthesis and NMR studies on a C3-symmetrical triquinolina triscationic bicyclophane

[structure: see text] Two-step syntheses of triple-bridged triscationic bicyclophanes are presented. Molecular modeling has been undertaken by means of ab initio calculations (6-31G level) on the triquinolina triscationic bicyclophane. This compound exists as two diastereomeric sets of enantiomers, one with C3 symmetry and the other with C1 symmetry. The C3-symmetrical derivative is 1.94 kcal mol(-1) more stable than its C1-symmetrical one. This energy difference is sufficient to consider the former and its enantiomer the only two conformations existing in solution at room temperature.     

Reaction of unsaturated sulfoxides with alkyllithiums

Nucleophilic attack of methyllithium on allene sulfoxides offers a stereospecific access to sulfur-free allenes. Reaction of phenylsulfinyl substituted diene $\text{15}$ leads via a benzilic-type rearrangement to phenyl substituted diene $\text{18}$.     

Nuclear magnetic moment of 12 d 11/2− 131mXe

NMR-ON measurements were performed on^131mXe (I=11/2^–; T_1/2=12.0 d) in Fe, the sample being prepared by recoil implantation after the¹³⁰Te(,3n)^131mXe compound reaction at E=40 Mev. The hyperfine splitting _NB_HF/h¦, extrapolated to zero external magnetic field, was found to be 209.9(1) MHz. Taking B_HF=+1523(8) kG for the hyperfine field of XeFe, the magnetic moment of^131mXe is deduced to be (–)0.994(5) _N. As a byproduct, the zero-field hyperfine splitting of^129mXe (I=11/2^–; T_1/2=8.9d) in Fe was measured as 188.1(1) MHz, with which a magnetic moment of (–)0.891(5) _N is deduced for^129mXe.     

An Improved Sub-component Fatigue Testing Method for Material Characterization

Experimental Techniques - In this paper an improved sub-component fatigue testing method is proposed, in which structural optimization is used to obtain specimens in which fatigue failure is...     

Atom-Economic Synthesis of Functionalized Octahydroacridines from Citronellal or 3-(Phenylthio)-citronellal

Here we present a simple, solvent-free, one-pot, hetero-Diels–Alder reaction of (R)-citronellal or 3-(phenylthio)-citronellal with arylamines using solid-supported catalyst (SiO₂/ZnCl₂). This general, efficient, and improved method is selective, affording preferentially new trans-fused 3-(phenylthio)-octahydroacridines (S-OHAs) in good yields. The use of microwave irradiation facilitates the procedure and accelerates the reaction.     

Clean and fast oxidative transformation of thiols to disulfides under solvent-free conditions

We present here a fast, solvent-free synthesis of symmetrical disulfides using solid supported catalyst (Al₂O₃/KF). The reaction was performed at room temperature, by gentle heating or under MW irradiation. This efficient and improved method is general for liquid thiols, affording the disulfides in good to excellent yields. The catalytic system can be re-used two times without previous treatment and with comparable activity.     

Über die hervorragenden reducirenden Eigenschaften des Kalium-Ferrooxalates und einige durch dasselbe hervorgerufene Reactionen

Ohne ZusammenfassungDie Arbeiten wurden im chemischen Laboratorium des Herrn Professor Dr. J. J. Pohl an der k. k. technischen Hochschule ausgeführt.