Motor on dating
(c) Crystal structure of enantiomerically pure Z-(R)-(M) isomer (CCDC 1406625).
Combined with its Z and E isomeric forms, motor 1 can thus assume four different diastereomeric structures for each configuration of the stereogenic sulfur centre, for example, Z-(S)-(P), Z-(S)-(M), E-(S)-(M) and E-(S)-(P), which can be distinguished by conventional spectroscopic methods. 39) was converted into the corresponding acid chloride, which subsequently underwent cyclization via intramolecular Friedel–Crafts acylation to give benzothiophenone 3.2a–c), as well as for both Z and E isomers of the corresponding unoxidized HTI (CCDC 1408096 and CCDC 1408097, see Supplementary Figs 37 and 38 and Supplementary Tables 2 and 3).(a) Crystal structure of racemic Z-(S)-(P)/Z-(R)-(M) isomers, only the Z-(S)-(P) isomer is shown (CCDC 1061969).(b) Crystal structure of racemic E-(S)-(P)/E-(R)-(M) isomers, only the E-(S)-(P) isomer is shown (CCDC 1061970).In the current state of the art, considerable efforts have still to be made to increase the efficiency of energy transduction and devise systems that allow operation in ambient and non-damaging conditions with high rates of directional motions.The need for ultraviolet light to induce the motion of virtually all available light-driven motors especially hampers the broad applicability of these systems.Direct assignment of the two separated species to the corresponding diastereomers was straightforward in solution, as NOESY NMR spectra showed specific cross-signals between the thioindigo and the stilbene part of the molecule (Supplementary Figs 6 and 11).
In addition, crystal structure analysis unambiguously confirmed our assignment of the species and their solution spectra.
Brook Crompton has a long history in electric motor development, dating back to 1878.
The modern Brook Crompton motor is based on the European design customers have come to depend on.
HTI consists of a thioindigo and a stilbene fragment, which are connected via a central double bond.
On irradiation, HTI undergoes efficient and reversible Z/E or E/Z photoisomerization.
Benzothiophenone 3 was subsequently condensed with indanone 5 using boron trifluoride diethyl etherate, after which a final oxidation with hydrogen peroxide furnished sulfoxide motor 1.