Determination of Geometries of some complexes of Ni(II), Cu(II)

Template reactions play a very important role in the formation of many natural macro- heterocyclic compounds that have biological activities such as porphyrine, metalloenzyme etc. and become one type of the most important reactions in bioinorganic Chemistry and other relating fields.
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Determination of Geometries of some complexes of Ni(II), Cu(II)Journal of Chemistry, Vol. 44 (4), P. 505 - 509, 2006 Determination of Geometries of some complexes of Ni(II), Cu(II) Received 5 July 2005 Vu Van Van, Nguyen Thanh Cuong, Le Kim Long, Lam Ngoc Thiem, Vu Dang Do Faculty of Chemistry, College of Natural Sciences, Vietnam National University of Hanoi Summary Calculations with 8 complexes of Cu(II) and Ni(II) with thiosemicarbazone bis(salicylaldehyde) were done within HyperChem 7.02 sotfware. The structure of complexes was determined. The UV-VIS spectra, single point of complexes were calculated and compared with experimental data. The calculated results have been confirmed by experimental structure of complexes. I - Introduction relating fields. In the early 1970’s, some Russian chemists Template reactions play a very important found a novel type of template reactionsrole in the formation of many natural macro- between thiosemicarbazone salicylaldehyde (1)heterocyclic compounds that have biological and salicylaldehyde (2) and the metal ions suchactivities such as porphyrine, metalloenzyme as Ni2+, Cu2+ (figure 1) [1]. It is necessary toetc. and become one type of the most important note that the condensation of 1 and 2 can notreactions in bioinorganic Chemistry and other occur without metal ions. - S S M = Ni2+, Cu2+, VO2+,. . . N NH N N N NH2 OH- M M O -H2O O O OH HO M(thsasal) anion 1 2 Figure 1: Template reaction The products of these reactions were studied of such products by quantum chemistryby methods of element analysis, conductivity calculations are given. It mainly deals withmeasurement, and magnetic moment measure- electronic spectra and geometry of thement ... but the data were relatively modest. It is complexes formed in the template reactionexperimentally studied the structure of the (figure 2).products by modern spectroscopic methods suchas IR, UV-Vis, MS and NMR to examine the II - Calculation Methodsproposed mechanism of the reaction [3]. In thispaper, some more data obtained about structure The calculations have been done within the 505software HyperChem 7.02 using semi-empirical carried out by ZINDO/S. Configuration Interac-methods. Calculations, which involve molecules tion (CI)-Singlely Excited method is chosen tocontainning transition metals, are only done calculate the electronic spectrum with both twowell with ZINDO/1 and ZINDO/S [4]. choices: Orbital criterion (the numbers of All molecules (3-10) are built, geometrically occupy orbital and unoccupy orbital) and energyoptimized by ZINDO/1 with convergence limit criterion (energy excited). Since orbital-crite-=10-5. All of algorithms have been tried. Only rion takes longer time and is not stable [4], onlyConjugate Direction algorithm is able to give Energy Criterion is used. The maximum chosenthe good geometry but it requires quite long energy has been varied to find the suitable one.calculating time. The other algorithms get Complexes with R = Na, K, NH4 areresults fast but with not fine geometry. electrolytically dissociated [1, 2], so they can be With the optimized geometry, the Single considered as M (thsasal) anion. However, whenPoint and IR Spectrum computation have been M are Ni (II), Cu (II) situation is quite different. S R M R Complex M R Complex N N N M Na 3 K 9 Cu O O K 4 CH3 10 Ni NH4 5 H 6 Figure 2: Complexes formed in CH3 7 template reaction of 1 and 2 CH3CO 8 III - Results and Discussion Ni, Cu) are adequate in each complex (1-9 and 1-21 bonds, 1-10 and 1-13 bonds) and change1. Geometry of complexes ...