A New Synthetic Route to Unsymmetrical 1,2-Bis(phosphanyl)ethanes and 1,2-Arsanyl(phosphanyl)ethanes with and without a Stereogenic Center

A one-pot reaction affords unsymmetrical 1,2-bis(phosphanyl)ethanes 2 and 1,2-arsanyl(phosphanyl)ethanes 3 from the cyclic sulfate 1 in high yield. Similarly, chiral 1,2-bis(phosphanyl)ethanes and 1,3-bis(phosphanyl)propanes could be obtained in enantiomerically pure form. R, R'=alkyl, phenyl.     

Synthesis of granulatimide analogues bearing a maleimide instead of an imidazole heterocycle

A synthesis in a few steps of a new family of granulatimide analogues was performed. In the new compounds, the aromatic framework of granulatimide is modified by replacement of the imidazole unit by a maleimide moiety. The synthesis of a water-soluble analogue is also presented.     

Low distortion recording of transient low- light-level phenomena

Two types of low-light-level image sensors have been investigated for use in low distortion recording: an SIT-vidicon (Silicon-Intensifier Target), and a sensor consisting of a newvicon and two stage proxifier. The results are compared and discussed. In addition, a triggerable video frame store is described.     

Evidence of continuous evolution of smectic A2 from smectic Ad

Abstract

We present here precise measurements of the layer spacing for two compounds, viz. 4-n-heptyloxyphenyl-4′-(4″-cyanobenzoyloxy)benzoate and 4-n-undecyloxyphenyl-4′-(4″-cyanobenzyloxy)benzoate. Contrary to earlier reports our data do not show any jump in the layer spacing at the expected A_d-A₂ transition temperature, showing thereby that for both compounds A₂ evolves continuously from the A_d phase.