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دراسة طيفية وثرموديناميكية لعدد من معقدات انتقال الشحنة المشتقة من تفاعل 3 - ميثوكسي - 4 - هيدروكسي بنزلديهايد وعدد من الامينات الاروماتية مع عدد من المستقبلات الالكترونية == Spectral And Thermodynamic Studies For A Number of Charge Transfer Complexes Derived From The Reaction of 3 - Methoxy - 4 - Hydroxy Benzaldehyde And Number of Aromatic Amine With A Number of Electron Acceptors

Author name: اماني اياد حسين علي
Supervisor name: عبد الرحمن خضير عبد الحسين الطائي
General topic: Chemistry
Specific topic: Chemistry
Degree: Master
University: Tikrit University - Faculty Of Education - Chemistry Department
Language: Arabic
University location: Salahaddin
First pages: 25T1519 - p.pdf
Abstract: الجزء الاول : وفيه تم تحضير تسعة من قواعد شف المشتقة من 3 - ميثوكسي - 4 هيدروكسي بنزلديهايد وعدد من الامينات الاروماتية متمثلة بالانيلين والانيلين المعوض ب ( 2 - هيدروكسي، 4 - هيدروكسي، 2 - امينو، 4 - امينو، 2 - كربوكسي، 4 - كربوكسي، 2 - نيترو، 4 | This work divided into three parts which is dealt with study of charge transfer complexes. Nine Schiff bases used in this work were prepared by mixing (1 : 1) mole 3 - methoxy 4 - hydroxy benzyldehyde and the corresponding aromatic amines (aniline ,2_hydroxy aniline , 4_hydroxy aniline , 2_amino aniline , 4_amino aniline ,2_carboxy aniline , 4_carboxy aniline , 2_nitro aniline , 4_nitro aniline).The electronic spectra in absolute ethanol solvent were used to study the intermolecular charge - transfer complexes between the considered Schiff bases as charge donor and five charge accepter molecules.Three of them are non - acidic acceptors such as (dinitro benzene DNB , Trinitro benzene TNB and Iodine I2 ) , another two are weak - acidic acceptors (Trinitro phenol TNP and p - nitro phenol p - NP ).The equilibrium constant of the CT complexes have been calculated by applying the Benesi - Hildebrands equation for (1x10 - 4 : 1x10 - 5 M) Schiff base : Acceptors concentration ratio. The equilibrium constants for complexes formation which are ranging between (1250 - 3000 mol - 1. dm3) with Iodine, (800 - 6000 mol - 1. dm3) with dinitro benzene, (833 - 4500 mol - 1. dm3 ) with trinitro benzene, (1000 - 5555 mol - 1. dm3 ) with para nitro phenol, (1000 - 6250 mol - 1. dm3) with Trinitro phenol ,The extinction coefficients have been determined were (3333 - 25000 L.mol - 1.cm - 1) with Iodine, (3333 - 25000 L.mol - 1.cm - 1) with DNB, (1111 - 20000 L.mol - 1.cm - 1) with TNB, (1111 - 20000 L. mol - 1.cm - 1) with p - NP , (2000 - 33333 L.mol - 1.cm - 1) with TNP.The ionization potential (Ip) of these bases also have been determined and are (6.02 - 8.90 e.V) with Iodine ,(11.6 - 14.15 e.V ) with Dinitro benzene (8.10 - 9.20 e.V) with trinitro benzene , (8.57 - 9.64 e.V) with Para nitro phenol ,(6.26 - 8.15 e.V) with Trinitro phenol for the Schiff base association constant , It way noticed that the values of all the physical parameters of CTC and Schiff bases are affected by the substituted group due to the increases or decreases in the stability of the carbonium ion character of the azomethane.The another part of this work deals with study of the effect of temperature on the value of equilibrium constant KCT in the range (298 - 318)0k for charge - transfer complex formations in addition the values of ?H , ?G0 and ?S0 of the CT complexes were calculated from the dependence of KCT upon the temperature , The negative values of the enthalpy which proves that the formation of CTC are exothermic and could occur spontaneously.Finally , the third part of this work deals with studying the kinetic of formation and decomposition of the CTC in ethanol.The results indicated , the more stable CTC decomposes slower whatever was the nature of the acceptors , and the rate constant for formations and decompositions followed first order.
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