American Journal of Chemistry 2015, 5(3A): 48-51 DOI: 10.5923/c.chemistry.201501.07 4-Hydroxycoumarins as New Fluorescent Compounds: Synthesis and Characterization Yasameen K. Al-Majedy 1,2,* , Ahmed A. Al-Amiery 1,2 , Abdul Amir H. Kadhum 1 , Abu Bakar Mohamad 1 1 Department of Chemical and Process Engineering, Universiti Kebangsaan Malaysia (UKM) 2 Chemical Division, Department of Applied Science, University of Technology Baghdad, Iraq Abstract New 4-hydroxycoumarins compounds were designed, synthesized and characterized as fluorescent compounds. Absorption and fluorescence spectra of these derivatives have been investigated in alcoholic media. The substituting groups with varying electron donating ability exhibits fluorescence at a longer wavelength i.e. 420-460 nm in ethanol in compound (1-5). Compounds 1-5 exhibited high quantum yield in ethanol. The fluorescence intensities of compounds 2 and 5 were extremely strong. Compounds 2 and 5 exhibited high fluorescent quantum yields in solution compared to compounds 1,3,4. Keywords Fluorescence, 4-hydroxy-coumarin, Emission, Synthesis 1. Introduction Fluorescent compounds play an important role in solid state lighting, solar energy conversion and as biomarkers in the life sciences [1-6]. As an important group of organic heterocycles, coumarin derivatives have been found to possess versatile pharmacological/biological activities, which can display anticancer [7, 8], anti-HIV [9], antiviral [10], antimicrobial [11], anti-inflammatory [12, 13], and antioxidant [14] activities, 4-Hydroxycoumarin and its derivatives have been effectively used as anticoagulants for the treatment of disorders in which there is excessive or undesirable clotting, such as thrombophlebitis [15], pulmonary embolism [16], and certain cardiac conditions [17]. Moreover, their unique photochemical and photophysical properties make them useful in a variety of optical application such as in optical brighteners, laser dyes, nonlinear optical chromophores, solar collector systems and organic lightemitting diodes (LED). Coumarin fluorescent probes or labels have extensive and diverse applications, as they exhibit extended spectral range and high emission quantum yields [18]. Coumarin-based fluorescent chemodosimeter with salicylaldehyde functionality were used as a binding site for selective detection of cyanide anions over other anions in water at biological pH [19], Shihai Zhou et al., [20] have studied 3-(2-benzothiiazolyl) coumarins for their fluorescent properties in which the coumarin acts as a donor while the benzothiazole moiety * Corresponding author: drab@eng.ukm.my (Yasameen K. Al-Majedy) Published online at http://journal.sapub.org/chemistry Copyright © 2015 Scientific & Academic Publishing. All Rights Reserved Scheme 1. Reaction sequences of the synthesized compounds acts an acceptor. P Moeckli et al., [21] introduced some new red fluorescent coumarin molecules by keeping electron donating group on 7th position of the coumarin ring and withdrawing group on 3-position. The oxygen