铕配合物[Eu（facam）3]的高分辨率CPL光谱测量

当手性化合物被非偏振光激发时，可以测量出左、右圆偏振光发射强度的差异。这种现象被称为圆偏振发光（CPL）。圆二色性提供了手性分子的基态信息，而CPL光谱则探测了手性分子的激发态。近年来，cpl活性分子被广泛应用于技术应用，如安全编码、生物分析探针和液晶显示设备。手性镧系配合物是CPL测量的目标分子的一个例子。这些复合物表现出尖锐的发射波段，并在CPL测量中需要一个狭窄的带宽。JASCO公司最近开发了一种高灵敏度的CPL光谱仪。通过将CPL与ECD结合，可以获得更多关于手性分子的结构信息。为了在高分辨率下测量尖锐的CPL峰，JASCO的CPL-300光谱仪使用了双棱镜单色仪。发射和激发单色器都配备了连续可变狭缝驱动，这允许适当的波长和带宽选择。结论：JASCO CPL-300光谱仪可以进行CPL测量，产生高分辨率的光谱。CPL、荧光和模糊光谱均与文献一致。Application NoteCDSSpectroscopy High-resolution CPL spectrum measurement of2/3Application Note High-resolution CPL spectrum measurement of a europium complex[Eu(facam)] Whe n ch i ral compou n ds are exci t ed w i t h unpo l ar i zed l i ght the d iffer e n c e i n em i s s i o n in t e n si ti e s o f l e ft- an d r i g h t -h a n d e d ci rc u l a r ly po la r ized l i ght ca n be m ea sured . Th i s ph e n omenon i s cal l ed c ir cu l arly po l a r ized lu mi nescence (CPL). W hil e c ir c ul a r d i c h r o i s m pr o v i d e s in f or m ati o n ab o u t the g r o u nd state of c h i r al mole c u l es ， CPL s p ectrosc o p y pr obes the exc i t ed states of chiral molecules. In recent yea r s ， C PL -ac t ive m o l ec u le s h a ve been u s ed fo r a w i d e ran ge of t ec h n ic a l appli cati o ns suc h as sec u r ity en c od in g， bi o a nalyti c al pr o b es ， an d l i qu i d cr ystal d i s p lay dev i ces . C h iral l a n th a n i de com p lexes are one example of target m ol ec u les fo r CPL m easu r e men ts. T hes e c omple x e s a re k n o w n t o e xhibit sh arp e m i s si o n b a n ds an d r e qu ire a n arrow b a n dwidth d u ring C PL m easurements . JASCO ha s r ecently developed a h i gh sen s i tivity CPL s p ectro m e t er. B y co m binin g C PL wi th E CD， m o re structu r a l in f o rmation reg a rd in g chiral m ol e cul e s ca n b e o b t a in e d.T o m ea s ure s h arp CPL peaks at a high resol u tion ， JASCO's CPL -300 sp e ctr o m ete r u s es t w o pri sm m o n o c hrom at o rs .B oth t h e e mi ssion an d exc it a ti o n mo n oc hr omators a r e equipped w i th conti n u o usl y va r ia bl e s l it d r ives ， w hi c h al l ow f or an app r op r i a t e w a v e l en gth and ban d w i d th sele c t i on . Th is a pp li c a ti on n ote de mon st r ate s th e h i g h re s o lu ti o n CPL spec t r u m measu r em e n ts o f eu r opi u m tris[3-(tr if lu o r ometh y lh yd r ox ymeth yl ene)-(+)-c a mphora t e](E u (fa c a m)3) u sing a CPL -300. E u(f acam )， i s a co mm o n NMR s h i f t rea g e n t and h as b ee n u sed as a standard f or C PL measu r eme n ts . Keywords JASCO INC. 28600 Mary's Court ， Ea s t on， MD 21601 U S A a europium complex Experimental 5.5 m M E u (fa c a m) was p r ep ared in D MSO. Excitation wavelength 373nm Excitation slit width 4000 um Emission bandwidth 3nm Scan speed 200 nm/min Response time 4 sec Data acquisition interval 0.1nm Accumulations 4 Path length 10mm The a bs o rp t i o n spe c t r um of E u(f a c am )./DM SO s o lu ti o n w a s m e a su r ed u sin g a V -760 s pe c trom eter a nd a 0.1 m m p a th length cyl in d r ical cel l a n d h older . The fl u oresce n ce s p ectra were ob t a i ned u s i ng a F P -8300 spectrofluo r i m ete r a n d a 10x10 mm p a thlen g th re c tangu l ar c e ll. Results In orde r to fi n d the e xc i t a ti o n m a ximum n eed e d t o o b tai n the C PL an d f luorescen c e emi s sion s p ectru m o f E u (fa c a m)3/D MSO， th e a b sorption s p ectru m was f irst obtaine d . Figu r e 1 d e pic t s a m a x imu m absorption peak (bl u e) at 309 n m.Howeve r， in order t o o p t i mi ze the exc it a ti o n w avele n gth u sed in the CPL an d fluorescence m eas u remen t s， an excita ti o n sp ectru m w as su b se q uen ti a lly measu r ed a t the exp ecte d e m is si o n m a x imu m pe ak 's w a v e l en gth at 613 n m. Th e excitati on spe c tr u m shows an apparen t m a x i mu m at 373 nm (Figure 1， r e d ). Th e exci t a ti o n wavel e n gth was s e t t o 373 nm and t h e CPL an d fluo r escence mea s uremen t s o f Eu(f aca m )3/DMSO were me a su r ed and a r e show n in Fi g u r e 2. Figure 1. The absorption (blue)， excitation (red) and emission (green) spectra of Eu(facam)./DMSO solution. 28600 Mary's Cour t ， E asto n ， MD 21601US A Figure 2. The gjum (top)， CPL (middle)， and fluorescence (bottom) spectra of Eu(facam) /DMSO solution. Al l th ree spec tra i n Fi g ure 2 sho w th e 5D， --> 7F，ma g net i c -d i pole tran s ition b a n d at 595 nm . The a ddition a l emiss i o n b a n d a t 611 n m is d u e t o t h e 5D，-->7F， e l ectron i c-d i pole transiti o n . T he C PL s p ectru m s h ows s tr o n g s ign a l s w h i c h con f irm s the prese n ce of the ch ir a l f aca m ligands. T he degree of C PL can be desc r ibed b y gm， the lum i n e scen t d i ssymme t ry fa c t o r.This value qu a n t if i es the asym m e tr ic e n v i ronm e nt su rr oun d in g the c omplexes 'metal ions. T h e l arger th e di s sy m m et r y fa c t o r ， th e more p o l ar i zed the e m it t ed l i g h t w i ll be. A g o f ±2 i n di ca t es t he co mpl e t e p o l arization of l ig ht wh i l e 0cor r el a t es to u np o l ar i zed e m itte d lig h t. Fig ur e 2 (top) s h o w s a gva lu e ca. -0.8 fo r the 595 n m tran s ition band ， ind i ca tin g a chir a l spec i e s i s present . Conclusion T he J AS C O C PL-300 s p e ctro met e r ca n p e rfo r m CPL me a s u r e me n t s th at prod u c e hi g h r e s olu ti o n sp e ctr a . 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