[xxdesigulxx]

Hi guys,

I need help identifying the product from the spectra. we did a lab on synthesis of benzyl alcohol(preparing benzyl alcohol from benzyl chloride),

Can some please help me identify the functional groups and the Product using the IR, NMR, and Mass spectrum.

Here are the links :

http://oi50.tinypic.com/5mzrpx.jpg       <-IR spectrum
http://tinypic.com/r/hvo4tj/6               <- mass S
http://tinypic.com/r/2qcnq5x/6             <- HNMR
 
thanks. one more thing the boiling point obtained was 160c!. please help me!. Thank you!

[discodermolide]

What groups have you identified up to now?

[Borek]

You have to show your attempts at solving the question to receive help. This is a forum policy, described in the forum rules.

[xxdesigulxx]

Hi.
 i was able to identify o-h (between 3400-3500), c-h (2800-3000), c-o(1100-1300)I dont know if i am rightIn hnmr the gap describes that there is unknown element present. So how can i use the mass spectrum to finthat? In mass spec. The parent peak is 122.so like is that the molar mass. I dont get it.

[discodermolide]

I do not see an OH stretch in the IR.
The peak at m/e = 91 tells you something. You have the MWt. 122, what fragment could be lost here?
What information can you get from the NMR?

[xxdesigulxx]

91 m/z is the base peak i think it tells you that there is benzyl unit present there. NMR there are 3 peaks so, 3 H present there, but i dont know how i can get the formula from there!:(

[discodermolide]

That's right the m/e at 91 is a benzyl radical cation, this fits with the NMR showing 5 aromatic protons.
So you have C₆H₅-CH₂-unknown-unknown.
So what could the unknowns be, does the loss of 31 in the mass. spec say anything? Along with 2H and 3H in the NMR.
Have a guess.

[xxdesigulxx]

is it due to ester?

[discodermolide]

No it is not an ester.
What compounds do you know with a mass of 32?
In the NMR both peaks are singlets. That is no coupling between them. The position of the 2H signal at 4.4 should indicate something to you.

[xxdesigulxx]

oh its sulfur. and the the position of 2h at 4.4 tells us that there is formaldehyde, ch2o present. am i right?

Thank you for immediate response. you are a big help. thanks so much!:)

[discodermolide]

No it is not sulphur, it is an organic fragment.
Formaldehyde is not present it is though CH₂O.
So we have C₆H₅CH₂O-unknown. The unknown part has 3 protons in it.
add up the mass of C₆H₅CH₂O and see what is left.

[xxdesigulxx]

the mass of that comes up to 107. so 122-107=15.

[xxdesigulxx]

lithium is the one that has 3 protons

[discodermolide]

Right, so which organic unit has a mass of 15, knowing that there are 3 protons in that fragment?

Look by protons I mean H atoms, you are looking at a proton NMR

[xxdesigulxx]

i dont get it!:(