Molecules Project 1: Chemiluminescence
Luuk Adema & Ewout van der Veer
S2794640 & S2680254 luukadema@hotmail.com & ewoutvanderveer@msn.com
31-10-14
F. Mecozzi, E. Hagting & M. van Zuylen
Abstract
Luminol was synthesized and the light intensity of its luminescence was tested. The yield of the synthesis was 55%. Measurements of the intensity of luminescence were done under standard and optimal conditions resulting in peak intensities of ±0.02 lux (standard) and ±0.03 lux (optimal). It has been shown that an increase in pH results in an increase in intensity with a maximum of pH=11.33.
Introduction
In this project, the chemiluminescence of luminol was studied. The project consists of two parts. First, luminol was synthesized in a two-step process. …show more content…
Luminol is synthesized in a two-step reaction. The first step is the condensation of 3-nitrophthalic acid. The product of this step subsequently reacts with sodium dithionite to reduce the –NO2 to –NH2. The reaction mechanisms for these steps are depicted below. …show more content…
This creates a molecule with several resonance forms, one of which can react with the catalyst, K3Fe(CN)6. The catalyst removes one electron from two of the dianions, which creates two radicals. These radicals react to form one dianion and one anion. Hydrogen peroxide reacts with carbonate ions to form a –O2H ion, which attached to the carboxylic carbon of the singly charged anion. The peroxide group is now deprotonated by carbonate again and a bond is formed between the negative oxygen atom in the peroxide group and the other carbon atom. Finally a molecule of nitrogen is abstracted to form a molecule in the excited triplet state. Through inter system crossing (ISC), the molecule is converted to the excited singlet state, from where is can fluoresce to the ground state, releasing a photon of wavelength 425
Luuk Adema & Ewout van der Veer
S2794640 & S2680254 luukadema@hotmail.com & ewoutvanderveer@msn.com
31-10-14
F. Mecozzi, E. Hagting & M. van Zuylen
Abstract
Luminol was synthesized and the light intensity of its luminescence was tested. The yield of the synthesis was 55%. Measurements of the intensity of luminescence were done under standard and optimal conditions resulting in peak intensities of ±0.02 lux (standard) and ±0.03 lux (optimal). It has been shown that an increase in pH results in an increase in intensity with a maximum of pH=11.33.
Introduction
In this project, the chemiluminescence of luminol was studied. The project consists of two parts. First, luminol was synthesized in a two-step process. …show more content…
Luminol is synthesized in a two-step reaction. The first step is the condensation of 3-nitrophthalic acid. The product of this step subsequently reacts with sodium dithionite to reduce the –NO2 to –NH2. The reaction mechanisms for these steps are depicted below. …show more content…
This creates a molecule with several resonance forms, one of which can react with the catalyst, K3Fe(CN)6. The catalyst removes one electron from two of the dianions, which creates two radicals. These radicals react to form one dianion and one anion. Hydrogen peroxide reacts with carbonate ions to form a –O2H ion, which attached to the carboxylic carbon of the singly charged anion. The peroxide group is now deprotonated by carbonate again and a bond is formed between the negative oxygen atom in the peroxide group and the other carbon atom. Finally a molecule of nitrogen is abstracted to form a molecule in the excited triplet state. Through inter system crossing (ISC), the molecule is converted to the excited singlet state, from where is can fluoresce to the ground state, releasing a photon of wavelength 425