III International Conference

PP-I-62QUANTUM-CHEMICAL STUDY OF Zn AND Ni ATOMS INTERACTION WITHPHENYLPROPARGYL AND CINNAMIC ALCOHOLS MOLECULESIvanova N.M.Institute of Organic Synthesis and Chemistry of Coal of Kazakhstan RepublicKaraganda, KazakhstanE-mail: nmiva@mail.ruThe analysis of interactions of Zn and Ni atoms in their complexes with phenylpropargyland cinnamic alcohols is performed on the base of quantum-chemical calculations byB3LYP/6-31G(d,p) method.The electrocatalytic hydrogenation of the triple carbon-carbon bond in phenylpropargylalcohol (PhePA) proceeds to the end by using of skeletal Ni for a cathode activation, andstops on the stage of cinnamic alcohol (CA) in the case of using Zn skeletal catalyst [1]. Thedifferent catalyzing effect of the metals is caused by the electronic structure of their externalshell: Ni …3s 2 3d 8 4s 2 and Zn …3s 2 3d 10 4s 2 . The calculations for model complexes M + PhePAand M + CA (M= Ni, Zn) carried out by means of B3LYP/6-31G(d,p) method with the aim ofthe more detailed analysis of the interaction of Ni and Zn atoms with phenylpropargyl andcinnamic alcohols.According to the obtained results, Ni atom interacts with acetylenic bond of PhePAforming a rather stable π-complex that is attended by the cis-bending of PhePA molecule:NiHOCCCHZ nHCCCHHHCCCHHOHCCCHCCHCCHCCHHHHIn the case of Zn the weak stable σ-complex is formed, in which Zn atom connectsstronger with one of the carbon atoms of acetylenic bond, as well as with oxygen atom of OHgroup.A small trans-bending of PhePA molecule is taking place in the complex. This is in agood agreement with experimental data [1] indicated that trans-isomer of cinnamic alcohol isa dominant product of electrocatalytic hydrogenation of PhePA on the Zn catalyst.As a result of coordinating interaction the partial positive charges arise on Ni and Zn:0,285 and 0,120 respectively. This indicates the electron density transition from the metal117