Recent Breakthrough in Synthesisu A huge synthesis effort has led to anefficient route into this target (500 mg inhand)u The new dye shows a monotropic SmA*phase, and mixes well with our standardhost for characterizationu The Boulder Model predicts a substantialincrease in <cos a> for thissystem—preliminary measurementsindicate this is correct (Pext ~ -500 nC/cm2)u A serious run at measurement of the EEOcoefficients for FLC NLO materials is underwayOO2NC5H11OOOC10H21NNNOC5H11OOOC10H21W482LC NLO Polymer Optical Fibers with a Photonic BandgapPrior Results: The First High P Main-Chain FLCPsOOONO2On780°C, vac,12 hrsOOONO2On7x3a : n=43b : n=33c : n=22a : n=42b : n=32c : n=2RuPCy3PCy3ClClPhPh2a X—66“A*”97.5“IX”C*”60—A*2b X—55“C*—63.5“A*”101.5“I2c X—70.5“A*”107.5“IX”C*”65—A*3a g ”13“C*”124-128“A*—154-159“I3b X—58“C*”113-115“A*—153-158“Ig”13—C*3c g”25“C*”116-118“A*—160-168“I• Direct Grubbs ADMET polymerization in the neat liquid (LC to LCP transformation) producesoligomers with DP about 10• These are the first high P main-chain FLCPs reported; their SSFLC switching behavior is nominal• The mesogenicity of the oligomers is excellent, but the glass transitions are below room temperature• The o-nitroalkoxy FLCs has a very small second order susceptibility (d22 about 0.6 pm/V for SHG)Walba, D.M.; Keller, P.; Shao, R.; Clark, N.A.; Hillmyer, M.;Grubbs, R.H. J. Am. Chem. Soc. 1996, 118, 2740-2741.Main-Chain FLC NLOP Glasses from Azo TwinsW473I — 87.8 “ SmC* — 64.5 “ XI ” 97.1 — XOOOONO2ONOOONN150:1 molar ratioPCy3RuPCy3ClClPhClClWater aspirator pressure,30°C, three daysI — 125 “ SmC* — 85 “ glassI ” 140 — SmC*MW 40K (DP about 30) by calibrated gel permeation chromatographyPolyW473u The sideways dimers can give SmC* phasesu Acyclic diene metathesis polymerization can giveoligomers with SmC* glasses at room temperatureFibers from Azo Twin PolymersCharacterization by PLMu Fibers pulled from the isotropic melt aremechanically stable at 5 µm diameteru Between crossed polarizer and analyzerthe fibers afford maximum transmissionwhen the fiber axis is 45° off thepolarizer axisu With only a polarizer, the fibers showmaximum transmission when the fiberaxis is parallel to the polarizeru The fiber’s fast axis is parallel to thefiber axisCharacterization by XRSu These X-ray layer spacings as afunction of temperature are fullyconsistent with a first order I - SmC*transition. The X-ray tilt angle isabout 45° in the SmC* phaseX-ray on Fibersu Main-Chain Along Fiber Axis– Transition moment of the dye is oriented normal to the fiber axis– Larger n for polarization normal to fiber axis (negative Dn!)u Smectic C* layers Normal to Fiber Axis– High-b group normal to fiber axis– What is the director doing?I — 125 “ SmC* — 85 “ glassI ” 140 — SmC*OOOONO2NNNOOOOClClPCy3RuPCy3ClClPh15 0:1molar ratioWateraspirator pressure,30°C, threedaysNLOP Fibers in Cross SectionMicrotomeThe director structure looks uniform!Chiral Quartz CrystalsChiral SodiumAmmonium RacemateCrystalsA Liquid Conglomerate?u Organic crystal conglomerates have been knownsince 1848.u Recently, good evidence for the existence of 2D-crystal conglomerates has been obtained.HO2CCO2HOHOHHO2CCO2HOHOH+1:1A 2D Crystal Conglomerate on GraphiteRSRacemateu A liquid conglomerate had never been seen until…OOOONNOC8H17OC8H17u 1929 Vorländer describes the first banana LCsu 1992 Cladis, Brand and Pleiner suggestpossibility of polar Sm “chevron” bilayer withC2v symmetry and helical chiralityu 1994 Matsunaga reports certain achiral bentmesogens give smectic C phases.u 1996 Takezoe and Watanabe et al report these"banana-shaped" molecules produceferroelectric phases with C2v layer structureand helical chirality, starting a wave of bananamania in the FLC communityu 1997 The Boulder Group proposes a chirallayer structure for the B2 phases(NOBOW): B4 — 155 “ B2 — 173 “ INonylOxyBOWC2V Symmetry:Polar & AchiralBanana