SYNTHESIS OF ECO-FRIENDLY DYES A THESIS SUBMITTED TO THE UNIVERSITY OF THE PUNJAB FOR THE AWARD OF DEGREE OF DOCTOR OF PHILOSOPHY IN CHEMISTRY Session 2010 SUBMITTED BY: RANA AMJAD AYUB BHATTI RESEARCH SUPERVISOR PROF. DR. MUNAWAR ALI MUNAWAR INSTITUTE OF CHEMISTRY UNIVERSITY OF THE PUNJAB, LAHORE. DEDICATDEDICATEDEDEDED To My Loving Family Prof. Munawar Ali Munawar Prof. Robert M. Christie Mr. Shehzad ...H.HHHassanassanassan.. Pervaiz, The prayers and guidance of all helped and enabled me to accomplish this project. Declaration I hereby declare that the work described in this thesis was carried out by me under the supervision of Prof. Dr. Munawar Ali Munawar at the Institute of Chemistry, University of the Punjab, Lahore. I also hereby declare that the substance of this thesis has neither been submitted elsewhere for any other degree. I further declare that the thesis embodies the results of my own research work or advanced studies and that it has been composed by my self. Where appropriate, I have made acknowledgement of the work of others. Rana Amjad Ayub Bhatti APPROVAL CERTIFICATE I hereby certify that Mr Rana Amjad Ayub Bhatti s/o M. Ayub Bhatti has conducted research work under my supervision, has fulfilled the condition and is qualified to submit the thesis entitled “Synthesis of Eco-friendly Dyes” in application for the degree of Doctor of Philosophy. Dr. Munawar Ali Munawar (Supervisor) Professor of Organic Chemistry. Institute of Chemistry, University of The Punjab. Lahore, Pakistan. ACKNOWLEDGEMENT All praises to the Al-Mighty “Allah ” who provided us with knowledge, sight to observe and brain to think. Peace and blessings of Allah be upon the Holy Prophet “Hazrat Muhammad” (SAW) who exhorted his followers to seek for knowledge from cradle to grave. I wish to express my heartfelt appreciation and gratitude to my research supervisor Prof. Dr. Munawar Ali Munawar (Professor of Organic Chemistry, Institute of Chemistry, University of The Punjab), for his valuable guidance and continuous encouragement throughout the course of this work. It was indeed an honour and pleasure working with him. I have no words to thank Prof. Dr. Robert M. Christie , under whose guidance I had the opportunity to do part of my research work at the School of Textiles and Designs, Heriot Watt University, Edinburgh, U.K. which eventually enabled me to accomplish this research project successfully. It was indeed an honour to work with a leading Colour Chemist like him. His guidance and constant support during the period is highly appreciable. I also acknowledge Prof. Dr. Saeed Ahmed Nagra , Director, Institute of Chemistry, University of the Punjab and Prof. Dr. Ch. Jamil Anwar , Dean, Faculty of Science, University of the Punjab, for providing outstanding working environment. I would like to express my deep appreciation to Prof. Dr. Misbah-Ul-Ain and Prof. Dr. Makshoof Athar for their sincere and valuable advices and outstanding support through out the time period. I owe my sincere gratitude to Dr. Roger Spark, Dr. Alan Boyd, Dr. Redhuwan, Maggie Robertson and Ann Hardie for their helping hand in my research work at Heriot Watt University Edinburgh. I would also like to thank Higher Education Commission , Pakistan, for providing financial support to carry out this work and my parent organization Pakistan Council for Scientific & Industrial Research (P.C.S.I.R) for allowing and facilitating me to carry out this research project. I cannot forget to thank Wasim Ibrahim, Abdul Waqar Rajput, Wasim Kaimouz (University of Allipo, Syria), and friends of Shish group for making my stay at Galashiels a memorable one. I am also thankful to my research fellows at University of The Punjab for their cooperation and support during the whole period. Special thanks to my parents for their help during my studies and providing me inspiration to accomplish this goal. The acknowledgement would be incomplete if I don’t mention to thank my brother and sisters for their love and prayers for my success. Rana Amjad Ayub Bhatti LIST OF ABREVIATIONS DCM Dicholormethane DMSO Dimethyl sulpoxide CHCl 3 Chloroform NMR Nuclear Magnetic Resonance spectrum s Singlet bs Broad singlet d Dublet t Triplet q Quartet Ar Aromatic ppm Parts per million ETAD Ecological & Technological association of dyestuff Manufacturing Industry IARC International Association for Research on Cancer TABLE OF CONTENTS CHAPTER-1 INTRODUCTION ............................................................................ 1 1. Colour ........................................................................................................... 1 1.1. Constitution of colour............................................................................... 1 1.2 Theories of Colour and Constitution ........................................................ 2 1.2.1. Classical theories ....................................................................................2 1.2.2 Modern Theories .....................................................................................4 (a) Valence Bond Theory (V.B.T) ................................................................4 (b) Molecular Orbital Theory (M.O.T) ......................................................... 5 1.3 Colorants ................................................................................................. 6 1.4 Classification of Dyes .............................................................................. 9 1.5 Types of Dyes ......................................................................................... 9 1.5.1. Acid dyes: ................................................................................................9 1.5.2. Reactive dyes: ....................................................................................... 10 Advantages of the Reactive Dyes .............................................................................. 10 1.5.3. Metal complex dyes .............................................................................. 11 1.5.4. Direct dyes: ............................................................................................ 12 Disadvantages of Direct Dyes .................................................................................... 13 1.5.5. Basic dyes .......................................................................................................... 13 1.5.6. Mordant dyes ......................................................................................... 14 1.5.7. Disperse dyes .................................................................................................... 14 1.5.8. Pigment dyes: ....................................................................................... 15 1.5.9. Vat dyes ................................................................................................. 15 1.5.10. Anionic and Ingrain dyes ...................................................................... 16 1.5.11. Sulphur dyes ......................................................................................... 16 1.5.12. Solvent dyes .......................................................................................... 17 1.5.13. Fluorescent dyes ................................................................................... 17 1.5.14. Food dyes .............................................................................................. 18 1.5.15. Natural dyes .......................................................................................... 18 1.6 Azo Dyes ............................................................................................... 19 1.6.1 Chemistry of Azo dyes ......................................................................... 20 1.6.2 Absorption spectra of the Azo compounds ........................................ 21 1.6.3 Effect of humidity on Azo dyes ............................................................ 21 1.6.4 Effect of temperature on Azo Dyes ..................................................... 21 1.6.5 Effect of Solvents on the λmax .............................................................. 21 1.7. Synthesis of Azo Dyes........................................................................... 22 1.7.1. Diazotization .......................................................................................... 22 1.7.2. Azo Coupling ......................................................................................... 24 1.8. Structure of Azo Dyes............................................................................ 26 1.8.1 Monoazo dyes ....................................................................................... 27 1.8.2 Disazo dyes ........................................................................................... 28 1.8.3 Trisazo and Tetraazo dyes .................................................................. 29 1.9 Coumarin Based Dyes........................................................................... 30 1.10. Flavone based Dyes .......................................................................... 37 1.11. Dye’s Toxicity..................................................................................... 39 1.12. Testing of Mutagenicity .......................................................................... 44 Project Aims...................................................................................................... 46 CHAPTER-2 EXPERIMENTAL ......................................................................... 47 2. Materials and Methods .............................................................................