UV visible spectroscopy

Electronic transition

Sigma to Sigma - eg:- alkanes
n to sigma
eg: -OH
Pi to Pi eg: saturated ketones
n to Pi
eg: aliphatic ketone

Chromophore

Independent

Dependent

Spectral shift

Bathochromic shift

Hypsochromic shift

Hyperchromic shift

Hypochromic shift

Auxochrome

Molecule which intensifies
the absorption when attached
to a chromophore
eg: -OH, -NH2

Instrumentation

Wavelength selector

Cells or cuvette

Radiation source

Detector

Uv

Visible

Filter

Monochromator

Slit

Photomultiplier tube
Linear diode array
Linear photo diode array

Beer lamberts law

A=abc
where, A= Absorbance
a=molar absorptivity
b= path length
c=concentration