6533b827fe1ef96bd12859f8
RESEARCH PRODUCT
Star-shaped conjugated compounds forming nematic discotic systems
Herbert MeierHans Christof HolstMatthias LehmannDirk Schwöppesubject
StereochemistryDiscotic liquid crystalOrganic ChemistryConjugated systemStar (graph theory)StilbenoidBiochemistrychemistry.chemical_compoundCrystallographychemistryLiquid crystalDrug DiscoveryStereoselectivityBenzeneTwo-dimensional nuclear magnetic resonance spectroscopydescription
Abstract Star-shaped compounds, having a benzene ( 9a,b ) or a 1,3,5-triazine ( 11a,b ) core and stilbenoid arms were prepared. Hexyloxy chains, attached in the middle of the arms, provide nematic discotic phases ND, which are unusual for such systems. The position of the sidechains prevents the micro-segregation, which is valid for star-shaped discs of columnar phases. The stilbenoid character of 9a,b and 11a,b guarantees a high light sensitivity. Apart from the statistical CC bond formation by irradiation in solution or in the LC phases, a topochemically controlled chemo-, regio- and stereoselective photocyclodimerization 11a → 12 was found in the crystalline state. The structure determination of 12 is based on different two-dimensional NMR techniques (COSY, NOESY, HMQC, HMBC).
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2004-08-01 | Tetrahedron |