 Corresponding author: El Hadji Gorgui Diouf Department of Chemistry, Laboratory of Natural Products, Faculty of Science and Technology, Cheikh Anta Diop University of Dakar, Senegal Copyright © 2022 Author(s) retain the copyright of this article. This article is published under the terms of the Creative Commons Attribution Liscense 4.0. Synthesis of second generation dendrimere PPI (G2) functionalized with 4- hydroxycoumarin effective for the removal of chromium (VI) by adsorption Talibouya NDIOR 1 , El Hadji Gorgui DIOUF 1, * , Mouhamadou FOFANA 1 , Fatou Dieng FAYE 1 , Cheikh GAYE 2 , Abdou Karim DIAW 2 , Balla FALL 2 and Moussoukoye Sissoko DIOP 1 1 Department of Chemistry, Laboratory of Natural Products, Faculty of Science and Technology, Cheikh Anta Diop University of Dakar, Senegal. 2 Laboratory of Electrochemistry of Cheikh Anta Diop University in Dakar, Senegal. GSC Advanced Research and Reviews, 2022, 13(02), 227–233 Publication history: Received on 05 October 2022; revised on 21 November 2021; accepted on 24 November 2022 Article DOI: https://doi.org/10.30574/gscarr.2022.13.2.0314 Abstract We report here the preparation of a second generation PPI dendrimer (G2) functionalized by 4-hydroxycoumarin based on the Manich reaction and its use for chromium (VI) removal. The literature review has shown that dendrimers are types of polymer defined by regular branches of a central monomer, which give it a tree molecular structure. Their ends carry functional groups whose arrangement gives rise to cavities that are able to receive other molecules as part of host- guest chemistry. To increase the generation or modify peripheral groupings it is possible to manipulate the properties during the synthesis of the dendrimer. Coumarins are a set of molecules with multiple beneficial properties including antioxidant, anti-inflammatory, anticancer, antibacterial, antiviral properties. It has also been shown that these molecules are good metal ion chelators and are able to modulate the activity of metrix metalloproteinases (MMPs). The study of adsorption, on a PPI dendrimer functionalized with Coumarin (C2), trivalent chromium and hexavalent chromium, shows that the kinetics are carried out in two steps with a significant removal efficiency for Cr VI (38.26%) and zero for Cr III. During this study, we kept the initial chromium concentration, pH, stirring rate, contact time and temperature constant and with the same amount of adsorbent (30 mg). Keywords: Dendrimer PPI; Coumarin; Chromium (VI); Adsorption; Adsorbent 1. Introduction Chromium can be released into the environment by various industries, including the metal finishing industry, iron and steel industry, and the production of inorganic chemicals [1]. It exists in several forms: trivalent (chromium III), hexavalent (chromium VI) or as an elemental metal (chromium 0). The toxicity of chromium depends not only on its concentration but also on its degree of oxidation. Indeed, it is commonly accepted that chromium (VI) is much more toxic than chromium (III). The latter is an essential nutrient for living beings since it plays an indispensable role in carbohydrate metabolism as an insulin activator [2].