Infrared spectroscopy help

http://riodb01.ibase.aist.go.jp/sdbs/cgi-bin/IMG.cgi?imgdir=ir&fname=NIDA4406&sdbsno=1721

Can you identify the C=C bonds peak in this IR

Question

Infrared spectroscopy help

http://riodb01.ibase.aist.go.jp/sdbs/cgi-bin/IMG.cgi?imgdir=ir&fname=NIDA4406&sdbsno=1721

Can you identify the C=C bonds peak in this IR

chmvijay · Answer

yaa if C=C bond is asymmetric usualy it shows peak around 1650 Cm-1

kociela · Answer

picture isn't showing up and gives forbiden banner, can be because of sdbs. (really distorted / shifted esteer spike get around that 1650?) other main pikes are 3100-3000 v(=C-H) and substitution is from 995-650 y(C=C-H) area. There is variation by substitution in those all, conjugated gives mainly ~1580-1640 and others above. double bond energy is generally lower (more stability) with more substituent and readings in the stable gives opposite so maybe something with conjugation and tightening the vibrating bonds (greater energy as in stable, higher cm^-1) ? can you upload that image separately ?