用J-1500 CD光谱仪测量镍和柠檬烯的近红外光谱

J-1500 CD光谱仪可用于使用扩展波长范围的光源和检测器对近红外区域（高达1600nm）进行光谱测量。在这种配置中，该仪器可用于振动跃迁的NIR-VCD测量和金属络合物的NIR-ECS测量。J-1500还可用于测量紫外线区域的ECD光谱，主要用于生物样品的研究。本应用说明表明，J-1500 CD光谱仪可以以高灵敏度探测CD光谱近红外区域的振动跃迁。Application Note Measurement of NIR-CD spectra of nickeltitrate and limonene using a J-15002/3Application NoteExperimental CDS Spect r oscop y Measurement of NIR-CD：spectra of nickel titrate and limonene using a J-1500 CD spectrometer In the nea r -in fr ared (NIR) r eg i o n ， observed CD s p ec t ra are a r e s u lt o f th e c o mbi n ation a n d ov e r t o n e v ibra ti o n a l mo d e s of th e O-H an d C -H tran si ti o n s (NIR -VCD)， as w el l a s the d -d tr a n si ti o n of m eta ll o-pro t e in s and metal complexes (N I R -ECD). NIR-ECD sp e ctra of met a ll o-prot e in an d met a l c o mpl e x e s are k n o w n t o b e sen si ti v e t o c o n f o rmati o n s of the metals ligands a s w ell as the co n figurat i on around the c e n t r a l me ta l a t o m， w hi ch i s u s e d f o r s tr uc tu r a l ana lysi s of th ese m o l ecules . For NIR -VCD， th e or ies an d c al c u la t ion m etho d s t o in terpre t th e N I R-VC D s p ectra ha v e been in tr o d uc e d an d c o mp ara tiv e an aly s i s f o r man y of th e spe ctra ha v e b e en a c co mpl is h ed. The J -1500 C D sp ect romet e r ca n b e u s ed f o r spectr a l m ea s uremen t s in t o th e NIR region (up to 1600 nm) using an e xt end e d wa v e l en gth ran ge l i ght s o urce a nd de t ect o r .I n th is c o nfigu r atio n ， th e i n s tr u m en t c an b e u sed fo r NIR-VCD measu r eme n ts of vibrat i ona l tr a n si ti o n s and NIR-ECD me a s ur e men ts of met a l co m pl e x es . The J-1500 c an also b e u s e d t o mea su r e th e E C D s pe ctr um in th e U V r e g ion，p r i m a r i l y f or t h e s tu dy of bi o l og i ca l sa mpl es. Th is app li catio n no t es demo n s t r ate s th e u se o f th e J -1500CD s p ectro m eter t o pr o b e vi b r a ti o n a l a n d e l ec t ro n i c tr a n s i tions of ni cke l tar tr at e solu ti ona n d l i mone n e? i n the N I R region o f th e spe c t ru m. Keywords J -1500， el e ctr o n ic c irc u l ar d ichro i s m， v ibrati o na l c i r c u l ar d i c h r o i sm， ne a r i n fr a r ed r e gi o n ， n i c kel t a r tr a te， l i mon ene ，N I R -ECD， NIR-VCD， metal complexes ， chem i ca l JASCO INC. 28600 Mary's Court ， Ea s t on， MD 21601 U S A Measurement conditions： nickel tartrate UV/Vis NIR Light source Xenon lamp Halogen lamp (optional) Detector PMT InGaAs (optional) Measurement range 235-940nm 940-1600 nm Spectral band width 1nm 16nm Data acquisition interval 0.1nm 1nm Path length 10mm 0.5 mm Scan speed 200 nm/min Response time 1sec Accumulations 1 time Gain 100X (InGaAs detector only) Measurement conditions： limonene Light source Halogen lamp (optional) Detector InGaAs (optional) Measurement range 1100-1350 nm Measurement mode CD/DC， UV single (Abs) Spectral band width 16 nm Data acquisition interval 0.1nm Scan speed 100 nm/min Response time 2 sec Accumulations 16 times Gain 100X A n ickel t a r tra t e s olutio n was p re par ed b y mi x ing 0.24 M ni ckel su lf a te solu ti o n an d 0.36 M sod iu m p ot assiu m t ar tr a t e s o lu ti o n wi th a 1：1 v o lu me r ati o. R-(+) a n d S -(-) li m on e n e w ere u s ed n e a t . Results A UV /Vis and N I R CD spe c tr um o f nick e l t a r trate so lu ti o n is show n i n Figu r e 1. Th e vert i ca l axi s i s conver t ed t o mo l ar ell ip t i cit y to compensate fo r the di ff erence in pa th le n gth fo r the spect r a co l lected i n t h e UV/is reg i on a n d NIR region .Th e s p ectra can b e mea s u re d with high sensiti v i t y up to 1600 n m， alt h o ugh s o me ab s o r p t ion f ro m H 20 i s ob s e rv ed i n th e reg i on a b ove 1400 n m. JASCO INC. Figure 1. CD spectrum of nickel tartrate solution i n the UV/Vis and NIR regions. Th e ab s o rpt i on and C D spe c t r a d er iv ed f ro m th e d o u ble o v e r t o n e of t h e C -H vibr a ti o n al tr an s i ti o n o f R -(+) an d S-(-)-limonene are s h o wn in Figure 2. R acem i c limonene was u s ed as th e basel i n e meas u rement f or the CD spec t r um.L i m o n en e was mea s u re d wi th a p a th le n gth of 10 mm and 2 mm b e c a u se there i s n o app ro p r i a t e s o lv e n t t o s er v e as the b a sel i ne f o r l iqu i d l i m onen e at roo m t em p era tu re in t he a b so r pti o n s p ectru m. T h e d iff ere nc e spe c t ru m (a b s o rpt io n equ i valent t o 8 m m path l e n gth) is m ul tip li ed by 1.25 an d conver t ed t o a n a b sorption equ al t o a 10 mm pa th lengt h. T h e v e ry w e ak CD s i g n a l be low 1 md e g c a n the re fo re b e m e a s u r e d w ith h igh s e n si ti vi t y. Figure 2. CD (top) and absorption (bottom) spectra of R-(+)-limonene (green) and S-(-)-l imonene (blue). Conclusion T h is app l ic a ti o n note d e mon s t r a tes t h at the J-1500 CD spectro m e t e r c a n be u sed t o pro b e v ibr a ti o n a l tr ansit i o n s i n th e n ea r in frare d r eg i o n o f t h e CD spectr um w ith high sen si ti vi t y . References 1. E at o n ， W. A.， P alme r ， G .， F ee ， J . A.， K i m ura， T .， a n d W. Lov en b er g， PNAS (1971)， 68，12， 3015-3020. 2. Abbate ， S .， C a stig l ion i，E.， Gang e mi ， F .， Gangemi ， R .， and G. L o n ghi， Ch i ra l ity (2009)， 21，1，242-252. 3. Ko n no， T .， M eg u ro ， H.， Mu rakam i，T.， a n d M. H a ta n o ， Chemist r y Letters (1981)， 953-956. JASCO INC.