Sections 1-3 Flashcards
(25 cards)
Infrared Light Tells us…
Types of functional groups
NMR Tells us…
Types of H, C, P, F, etc…
How many, what they are connected to
UV/VIS Tells us…
Double Bonds, Conjugation, Quantitative Concentrations
Mass Spec Tells us…
Molecular weight and formula
v is the symbol for
Frequency
λ is the symbol for
Wavelength
Radiowaves (NMR) cause
Spin flip
Microwaves cause
Rotations
Infrared waves cause
Vibrations/Stretching and bending of bonds
UV/Vis waves cause
Valence Electron Transitions
X-Ray waves cause
Core electrons transitions
Wavenumber is defined by:
1/λ (λ in cm)
Strong colors are caused by compounds with
ϵ > 1000
Weak colors are caused by compounds with
ϵ < 50
Main group inorganic compounds absorb
UV (appear white)
Intense colours in transition metals are caused by
Charge-transfer bands
Weak colours in transition metals are caused by
d -> d transitions
Ligand to Metal Charge Transfer
Electron from ligand orbital transferred to empty metal orbital
L - M -> L+ - M-
ϵ > 1000
allowed
Metal to Ligand Charge Transfer
Electron from metal orbital transferred to empty ligand orbital
L - M -> L- - M+
ϵ > 1000
allowed
Electron-poor metals form what charge transfer
L -> M
Electron-rich metals form what charge transfer
M -> L
d -> d transitions
ϵ < 50
degenerate d-orbitals split
forbidden
Organic with pi bonds
ϵ > 1000
wavelength = 190+30 per conjugation
allowed
Organic with pi bonds AND lone pairs
ϵ < 50
forbidden
wavelength = 280+30 per conjugation
