Utilization of IR spectral detailed analysis for coordination mode determination in novel Zn-cyclen-aminoacid complexes

The infrared spectra, elemental and thermal (TG/DTG and DTA) analyses of novel [Zn(cyclen-kappa N-4(1,4,7,10))(HGly-kappa O-2,O')](ClO4)(2) (1), and [Zn-2(Cyclen-kappa N-4(1,4,7,10))(2)(mu-S-Ala-kappa N-2,O)](ClO4)(3)center dot 2H(2)O (2) complexes (cyclen - 1,4,7,10-tetraazacyclododecane) were recorded and analyzed in the relation to their structural peculiarities. IR spectral data indicate both mono- or bidentate coordination mode of a carboxylate group in the prepared complexes (at pH approximate to 9). The results indicate unusual bidentate carboxylate coordination mode (in complex (1)) toward to Zn2+-cyclen unit. Therefore the crystal structure determination of the crystalline complex [Zn(cyclen-kappa N-4(1,4,7,10))(NO3-kappa O-2,O')](NO3) was attached in order to support the coordination mode assignment in complex (C). 2010 Elsevier B.V. All rights reserved.