The College of Education for Pure Sciences in the Department of Chemistry at the University of Basra discussed a master’s thesis on (preparation and study of the physical properties of implicit complexes between cyclodextrins and Schiff bases derived from anthranic acid)
The thesis presented by the researcher (Mohammed Hafez Hamid) included the preparation and study of the physical properties of the implicit complexes between cyclodextrins and Schiff bases derived from anthranic acid.
Cyclodextrins:-
It is a group of natural products formed during the bacterial decomposition of cellulose. Which can split and rearrange the polymer chain of starch leading to the formation of various cyclodextrins. Therefore, dextrins are non-reducing cyclic sugars that are crystalline and homogeneous consisting of glucose units.
Cyclodextrins (CDs) were first isolated by Antoine Villiers in 1891.
Depending on the glucose sugar units, the most common cyclodextrins are (α-cyclodextrains, β-cyclodextrains, γ-cyclodextrains) referred to as the first generation or the original and contain different numbers of glucose units (6, 7, 8), respectively. These units are related α-(1→4) glycosidic bonds.
These bonds that form between glucose units form V-shaped ring structures, which are equal in length with the same depth of 7.9 Å and different in width depending on the number of glucose units that make up the ring. The inner cavity of CDs is hydrophobic and lipophilic (somewhat non-polar) because The inner surface contains glycosidic oxygen atoms and structural carbon atoms, so it is hydrophobic, so the unbonded electron pairs of glycosidic oxygen bridges form inside the cavity, resulting in a high electron density, which gives it some properties of the Lewis base.
Aim of the study
Preparation of two Schiff bases derived from the reaction of para-aminobenzoic acid with each of ethylvanillin (M1) and orthovanillin (M2).
Three implicit complexes of each of the two bases were prepared with (α-CD, β-CD and 2HP-β-CD) by freeze drying and co-precipitation, and the physical properties of the prepared Schiff bases were prepared in their free and complex conditions with Dextrins (α-CD, β-CD, and 2HP-β-CD) to know the effect of complex formation on the solubility of these compounds, which is known by its low water solubility.
The size of the particles and particles as well as their area were calculated based on XRD and SEM data.
CONCLUSIONS Message
The study indicates that implicit complexes can be prepared easily between Schiff bases and different cyclodextrins by two methods (lyophilization and co-precipitation) and by using deionized water.
The preparation of the underlying complexes by lyophilization method gave better results than the co-sedimentation method.
The guest-host interference can be effectively diagnosed using IR and 1H-NMR technologies.
The solubility of Schiff bases in water can be improved when implicitly complexed with cyclodextrins and this is confirmed by XRD data.
The size of the particles and particles as well as their area can be calculated based on the XRD and SEM data.
message recommendations
First: Conducting some physical tests, such as a natural study of the fluorescence of bases, which showed the presence and absence of cyclodextrins.
Second: Using other methods to prepare implicit complexes with different cyclodextrins and studying the nature of their interaction
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