Structure,spectra and reactivity of terbutaline-metal(II)complexes

Eight divalent metalcations(M(II),M=Ca,Mg,Mn,Zn,Cu,Ni,Fe,Co)with clenbuterol representative terbutaline(L)in the formation of the singly metalated complexes(ML)are systematically investigated to appreciate their structure,UV-Vis spectroscopy,and reactivity properties by using density functional theory,with density functional theory B3LYP method,6-311+G(d,p)basis set level and time dependent DFT,conceptual DFT approaches.Their bonding properties are analyzed by the natural bond orbital analysis.Binding energy of complexes and natural bond orbital analysis shows,L combined with M(II)ions to form stable complexes,N,O atom lone pair of electrons and metal M on an empty orbital interactions contribute to the stability of complexes over large.The results of TD-DFT showed that except ZnL,the other 7ML molecular UV absorption spectrum peak than a precursor L has a larger red shift.Functional activity index shows the reaction after the formation of ML are stronger than L reactive monomer.Energy decomposition analysis shows that the electrostatic effect is enhanced reactivity of complexes ML main contribution of entry,while three-dimensional effect,or exchange-correlation energy also has some contribution.