...Objective: To synthesize the bis(acetylacetonato) copper(II) complex Introduction Complexes consist of a central metal atom surrounded by various other atoms or small molecules called ligands. All ligands are electron pair donor which act as Lewis base. The bonding between metal and ligand generally involves formal donation of one or more of the ligand's electron pairs. The number of ligands bound to the transition metal ion is called the coordination number. The natures of ligand are the availability of coordination sites or ligating atoms and the conditions under which these are available for coordination. One of the ways to prepare coordination compounds is through the direct combination of a metal ion and appropriate ligands in solution. Thus, the addition of a sufficiently high concentration of ammonia to an aqueous solution of a nickel2+ salt leads through a series of reactions. Complexes of metal ions in high oxidation states are sometimes more readily formed by adding the ligands to a solution of the metal ion in a lower oxidation state in the presence of an oxidizing agent. Thus, addition of ammonia to an aqueous solution of a cobalt2+ salt in the presence of air or oxygen leads to the formation of cobalt3+-ammine complexes such as hexaamminecobalt3+, [Co(NH3)6]3+, and pentaammineaquacobalt3+, [Co(NH3)5(H2O)]3+, ions. Apparatus and materials: Copper(II) nitrate, ammonia, acetylacetone, distilled water, glass rod, beaker, suction filtration set, oven, dropper...
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...Title : Preparation of bis (acetylacetonato)copper (II) Objective : I ) To synthesize the bis (acetylacetonato)copper (II) complex II) To determine the percentage yield of bis (acetylacetonato)copper (II) complex Background of study : Metal acetylacetonates, formed by a metal and multiple acetylacetonate anions, are prime examples of coordination complexes. In this experiment, the metal use is copper (II) ion which is crystal blue in colour when it is copper(II)nitrate. All metal ions in solution can react well with water. The water molecules can also be weakly bonded or more strongly as a ligand to form a complex ion, and these can also present in solid ‘hydrated’ salts of crystallization. For example, copper (II) nitrate (Cu(NO3)2∙3H2O) A complex ion has a metal ion at its center with a number of other molecules or ions surrounding it. These can be considered to be attached to the central ion by co-ordinate (dative covalent) bonds. The molecules or ions surrounding the central metal ion are called ligands. Simple ligands include water, ammonia and chloride ions. All ligands are lone pair donors. In other words, all ligands function as Lewis Bases. A base is an electron pair donor and an acid is an electron pair acceptor. Ligands like water, can donate a pair of non-bonding electrons(lone pair) intro a vacant orbital of a central metal ion and so dative covalent(co-ordinate) bonds hold a complex together. The central metal ion with vacant bonding orbitals can...
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