In IR spec strong bonds vibrate at ______ frequencies leading to a _____ wavenumber absorption
Higher, higher
What is inefficient at absorbing IR spec
symmetrical double bonded Cs and triple bonded Cs
The greater the dipole moment in IR radiation leads to
Greater absorption, then a stronger signal
Double bonds are located at what signal in IR
1600-1850
Triple bonds are located at what signal in IR
2100-2300
X-H bonds are located at what signal in IR
2700-4000
IR frequency equation
Frequency (v)= speed of light (c) / wavelength
IR wavenumber equation
wavenumber (V line on top)= V (frequency of light) / speed of light (constant)
What is mass spec and what is it used for
To determine the molecular weight and molecular formula of a compound, it is the study of the interaction between matter and an energy source
M+ peak indicates what
Molecular weight
Nitrogen rule in Mass spec
Even number of MW indicates even number of Ns while odd number of MW indicates odd number of Ns
Compounds containing Cl in their Mass spec will...
Have a M+2 peak will be one third of the parent peak
Compounds containing Br in their Mass spec will...
Have an M+2 peak that is the same height as the molecular ion peak
The higher the peak the more ____ the fragmentation
Stable
Signal at M-15 indicates
Loss of a methyl radical ( shown at M/z= 57)
Signal at M- 29 indicates
Loss of a ethyl radical at m/z=43
Signal at M-43 indicates
Loss of a propyl radical shown at m/z=29
Signal at M-57 indicates
Loss of a butyl radical shown at m/z=15
Signal at M-18 indicates
Loss of a H20 (characteristic of an Etoh)
Signal at M-x indicates (x being an even number)
Mclaffentry rearrangement (ketones and aldehyde)
Homotopic
Protons that are interchangeable by rotational symmetry
Enantiopic
Protons that are not interchangeable by rotational symmetry but are interchangeable by reflectional symmetry
diasterotopic
Protons that are neither interchangeable by rotational symmetry or reflection symmetry
In IR spec what appears at 1720
A ketone
In IR spec what appears at 1680
a conjugated ketone
In IR spec what appears at 1740
an ester
In IR spec what appears at as a broad spectrum around 2700-3400
a Carboxylic acid ( double bonded oxygen attached to an OH)
In IR spec what appears as 2 expressions at 3300 and 3400
Primary amine
In IR spec what appears as one expression at 3300
Secondary amine
In IR spec what appears as a broad spectrum at 1700
Aldehyde
In IR spec what appears as a mildly broad spectrum at 3400 with hump between 3000
Etoh group
CH3 shows a signal at? (broadband decoupled, Deept-90, and Dept-135)
Broadband decoupled and dept-135
CH2 shows a signal at? (broadband decoupled, Deept-90, and Dept-135)
Broadband decoupled and a negative signal at Dept-135
CH shows a signal at? (broadband decoupled, Deept-90, and Dept-135)
All 3
C shows a signal at? (broadband decoupled, Deept-90, and Dept-135)
Only broadband decoupled