Start of Orgo II, yikes...

Gamma Rays cause?

Ionization

UV’s cause?

Electron Transitions

Infrared causes?

Molecular Vibrations

Microwaves cause?

Rotational Motion

Radio causes?

Nuclear Spin Transitions

IR spectroscopy determines?

Functional Groups

NMR is for determining what?

Arrangements of carbon and hydrogens, uses radio waves

UV-VIS Spectroscopy is for what

Determining pi conjugated systems

Different kinds of molecular vibrations IR causes

Stretching and bending

What determines IR spec intensity?

Strength of bond dipole movement

What determines IR spec WAVENUMBER, not intensity?

Strength of bond and mass

Remember this order

Vaporize, Ionize, Accelerate, Separate, Detect

M/Z in a mass spectroscopy uses what?

Mass/Charge ratio

Electron Impact

How Mass spectrometers ionize molecules

Base Peak vs Molecular/Parent Ion

Base peak is most abundant, Molecular/Parent ion is the molar mass

Bromine M and M+2 are

50/50

Chlorine M and M+2 are

3:1

Amines (NH2, no carbonyl) and OH typically undergo?

Alpha cleavage

OH can also undergo?

Dehydration

Ketones may fragment how?

Lose an R group, leading to carbonyl doing resonance

Aldehydes may fragment how?

Same as ketones, but with an H group to do resonance

Number of HNMR signals?

Number of different TYPES of hydrogens

Chemical Shift (Location of the HNMR signal?)

Tells about its environment

Integration (area under the HNMR signal)

Indicates relative number of hydrogens in the signal

Multiplicity (signal splitting)

Indicates number of hydrogens on adjacent atoms

Look out for what sneaky hydrogens?

2 hydrogens on a carbon, look for homotopic/enantiotopic/diasteroptopic

More shielded = more electron density = appear where?

Low numbers (right), since it is harder to move them so they chemically shift less.

Chemical shifts are measured in?

parts per million (ppm)

The more methylated a carbon?

The more shielded the hydrogens = lower PPM

Hydrogens near stronger electronegativities have what happen?

They get deshielded from electron stealers, and gain PPM

Important slide, memorize this concept that integration values (number given) corresponds to RATIO of hydrogens

Nice slide on splitting

7 HZ

Free rotation HNMR

10 Hz

Cis HNMR of alkene

15 Hz

Trans HNMR of alkene

2 Hz

Diastereotopic alkene

6 Hz

Allylic hydrogen of alkene

What functional group is sneaky and always appears as a singlet?

Aldehyde

Do axial and equatorial hydrogens on chair conformations give 1 or 2 signals?

1 at regular temps, 2 at -80 C

What 2 functional groups are NOT split by OTHER hydrogens?

OH and NH/NH2, identifiable by D2O by making their signals disappear

What types of solvents for HNMR must be used?

Solvents without hydrogens, so mostly deuterated solvents (D instead of H)

Chlorofoam-d

Methylene chloride-d2

Acetonitrile-d3

Benzene-d6

Deuterium oxide