Bazı 4-(Dimetilamino) Benzaldehit-Metal Komplekslerinin Sentezi, Spektroskopik ve Termik Özellikleri

Abstract

Ill OZ Bu çalışmada, 4(Dimetilamino)benzaldehit'in(DMABA) V(IV), CtÇOI), Mn(n), Fe(m), Co(II), Ni(II), Cu(H), Zn(H), Cd(H) ve Hg(ü) kompleksleri sentezlenerek, spektroskopik özellikleri UV/VIS, İR ve NMR teknikleri ile incelendi. Komplekslerin manyetik duyarlık ölçümlerinden spin manyetik momentleri hesaplandı ve tüm paramanyetik komplekslerin yüksek spinli oldukları bulundu. Komplekslerde bağlanmanın aydınlatılması amacıyla Mn-DMABA kompleksinin tek kristali hazırlanarak X-ışınları tek kristal metodu ile moleküler yapısı araştırıldı. Kristalin monoklinik ve geometrinin bozulmuş oktahedral olduğu belirlendi. Komplekslerin termik davranışları TG, DTG ve DTA teknikleri ile incelendi. İlk bozunma sıcaklıkları kullanılarak komplekslerin termik kararlılık sırası V(IV) < Co(II) = Cr(IH) < Mn(H) < Ni(II) < Cu(H) < Hg(H) < Fe(III) < Znfll) < Cd(H) olarak bulundu. Yapılan ve termik kararlılıkları arasındaki ilişki tartışıldı. Bazı komplekslerdeki ilk bozunma reaksiyonlarının kinetik analizi Jeres düzeltmeli Freeman ve Carrol metodu ile yapılarak, aktivasyon enerjileri ve reaksiyon dereceleri hesaplandı. Komplekslerin termik bozunma mekanizmaları önerildi.

IV ABSTRACT In this study 4-(dimethylaniino)benzaldehyde (DMABA) complexes öf V(IV), Cr(III), Mnfll), Fe(m), Co(II), Ni(II), Cu(II)s Zn(II), Cd(II) ve Hg(II) were synthesized and their spectroscopic properties were investigated by UV7VIS, IR and NMR techniques. The spin only magnetic moments have been calculated from the magnetic susceptibility measurements of the complexes. The magnetic moments showed that all the paramagnetic complexes were high spin type. The crystal structure of the DMABA complex of Mn(H) has also been studied to understand the bonding in these complexes and its structure was investigated by X- ray single crystal method. It was found that, the crystal has a monoclinic structure and geometry of the Mn ion in the complexes is distorted octahedral. The thermal behaviour of these complexes were investigated by means of TG, DTG and DTA techniques. The sequence of thermal stability of these complexes by using the initial decomposition temperature was found to be V(IV) < Co(II) s Cr(m) < Mn(IT) < Ni(IT) < Cu(II) < Hg(n) < FeQS) < Zn(H) < Cd(n). The relationship between the thermal stability and the structure of complexes was discussed. Some of the kinetic parameters, such as the activation energy and order of reaction for the initial decomposition reaction of the some metal-DMABA complexes were calculated by using Jeres* modification of the Freeman and Carrol method. The mechanism of decomposition of complexes was also suggested.