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We report polarization-analyzed, resonant x-ray diffraction at the sulfur K edge performed upon free-standing liquid-crystal films. Our studies of the thiobenzoate liquid-crystal enantiomer 10OTBBB1M7 yield the polarization states of resonant satellite peaks arising from characteristic superlattices in the chiral smectic-C (SmC(*)) variant phases, including the antiferroelectric SmC(*)(A), ferrielectric SmC(*)(FI1) and SmC(*)(FI2), as well as SmC(*)(alpha). The observed polarizations agree with the clock model of chiral smectic-C variants, and rule out other proposals made to date for these structures. Data from the 10OTBBB1M7 racemate also support the clock model. Our resonant diffraction results from a thiophene liquid-crystal compound reveal the same superlattice periodicities seen in corresponding antiferroelectric and ferrielectric phases of 10OTBBB1M7.

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Reaction of ¿rans-l-Cyclohexyl-2,3~dibenzoylaziridine (25) with Enedione 1.-A solution of 62 mg of enedione 1 in 5 ml of toluene containing 165 mg of aziridine 25 was heated at reflux for 2.75 hr. Concentration and filtration gave 181 mg (80%) of crude solid product. This was recrystallized several times from benzene to yield an analytical sample of adduct 27: mp 175.5-177°; ir (KBr disk) 1765 (m), 1720 (s), 1675 (s), 1660 (s), 1230 (s) cm-1; nmr (CDC1.) 8 0.5-2.0 (m, 10 H, CH2), 1.12 (s, 3 H, CHa), 1.20 (s, 3 H, CHS), 2.28-2.80 [broad, 1 H, C(1)H of cyclohexyl], 3.