L3 Rich: IR spectroscopy part 2 Flashcards Preview

1st Year sem 2 : Forensic Analysis > L3 Rich: IR spectroscopy part 2 > Flashcards

Flashcards in L3 Rich: IR spectroscopy part 2 Deck (25):
1

what affects the position of bands in the IR spectrum?

mass of the atoms
strength of the bond

2

stronger the bond the ____ the _____

higher the frequency

3

the bigger the molecules the more?

complex the IR spectrum

4

what do we to do when we have large molecules?

do not try and assign specific vibrational modes

5

What to think when looking at IR of large molecules?

think of one or two bonds that are moving

6

what is key when looking at a large molecules IR spectrum?

Assign functional groups to specific frequencies

7

what region is looked at first when interpreting IR spectra?

the higher regions
1600+

8

what kind of peak is N-H?

sharp

9

what kind of peak is O-H?

It is broad (usually)

10

whats the lower region or IR and whats it also known as?

400 - 1600
fingerprint region

11

what peaks can sometimes be found in the fingerprint region?

c-cl
c-f

12

what number in the IR spectra shows a bond to hydrogen?

2500+

13

what happens when the mass is low?

vibrational frequency is high

14

what is the triple bond region?

2000- 2500

15

what region doesn't usually have peaks and why?

2000-2500
the triple bond
as its uncommon

16

Name two triple bonds?

C---N
C---C

17

what stem double bond region?

1500- 2000

18

Name two double bonds?

C--O
C--N

19

which double bond peak has more intensity, C -- O or C-- N?

C -- O

20

where's the single bond region?

500 - 1500

21

what dominates the single bond region?

C-C
C-O
C-CL

22

Which single bond peak is intense?

C-CL

23

what do you need to do if you suspect theirs inorganic molecules?

look at an inorganic table provided

24

what do you need for an IR peak to be present?

covalent bond

25

what pea is usually at 2900?

C-H