SYNTHESIS AND STUDIES ON TRANSITION METAL COMPLEXES OF BENZALDIMINO-1,3, 4-THIADIAZOLE -2-THIOL

MASTER OF SCIENCE IN CHEMISTRY

A. JEEVIKA(REG.NO.09PC06)

DEPARTMENT OF CHEMISTRY THIAGARAJAR COLLEGE (AUTONOMOUS

(Affilliated to Madurai kamaraj university) MADURAI-625 009.

APRIL – 2011

COORDINATION CHEMISTRY

The term coordination chemistry is generally used

to describe the chemistry of metals and metal ions

in their interactions with other molecules or ions.

The chemistry of inorganic complexes is at present

undergoing a period of rapid development and is

engaging the attention of research worker in many

diverse disciplines, both experimental and

theoretical progress in the area of chemistry.

INTRODUCTION

we have designed a series of amino-

substitution compounds with electron

withdrawing and electron-donating

groups on both terminals of the two

aromatic substitution. Keeping this in

view, we have synthesized some new

imine derivatives of 5-amino-1,3,4-

thiadiazole-2-thiol for their metal(II)

complexes.

AIM AND SCOPE OF THE PROJECT

To prepare transition metal(II) complexes with

benzaldimino-1,3,4-thiadiazole-2-thiol (BTT).

To prepare benzaldimino-1,3,4-thiadiazole-2-thiol

To characterize these complexes by physical and chemical

and spectral methods.

SCOPE

Metal(II) Complexes behave as model compounds similar to

bio molecules, involved in electron transfer reactions,

energy transfer reaction, protein synthesis, oxygen carrier

etc,.

EXPERIMENTAL METHODS

SYNTHESIS OF LIGAND

Preparation of benzaldimino-1,3,4-thiadiazole-2-thiol (BTT)

All complexes ( M = Cu(II), Ni(II), Co(II) and Zn(II)) were synthesized from

anhydrous metal(II) chlorides and the ligand. Anhydrous metal(II) chlorides were

prepared by dehydrating the metal chlorides at 150°C in oven for one hour.

Synthesis of copper(II) complex

Synthesis of nickel(II) complex

Synthesis of cobalt(II) compleX

Synthesis of zinc(II)complex

SYNTHESIS OF COMPLEXES

RESULTS AND DISCUSSIONS

IR spectral studiesElectronic spectral studies ESR spectrum Electro Chemical Behaviour NMR studies

we have characterized our compound using above spectral methods.

S.No Compound Molecular weight

Molar condctance (Λm)

Ω-1 cm2 mol-1

Magnetic

moment (µeff)

BM

1. [Cu L2Cl2] 576.48 20.2 1.6

2. [Ni L2Cl2 ] 571.60 18.9 2.7

3. [Co L2Cl2] 571.93 21.2 4.2

4. [Zn L2Cl2] 578.28 25.2 -

Magnetic moment and conductance of the metal complexes

S.No Mode of viberation

Observed band

region (cm-1)

Ligand Copper

1. ν(S-H) 2668.03 -

2. ν(C=N) 1540.85 1531.2

3. ν(C=S) 1294.97 1281.47

IR Spectral data of ligand(BTT) and their copper complex

S.No Mode of viberation

Observed

band region (cm-1)

Ligand Copper

1. ν(S-H) 2668.03 -

2. ν(C=N) 1540.85 1531.2

3. ν(C=S) 1294.97 1281.47

IR Spectral data of ligand(BTT) and their copper complex

S.No Compounds Frequency(cm-1)

Assignment Geometry Magnetic

Moment(µeff)

BM

1. Ligand(BTT) 3115238910

INCT - -

2. [Cu L2Cl2] 14144 Eg→T2g

Distorted Oh 1.6

3. [Ni L2Cl2 ] 1018311415

3A2g (F)→3T2g ( F)3A2g (F) →3T1g (F)

Oh 2.7

4. [Co L2Cl2] 10193 4T1g (F)→4A2g (F) Octahedral 4.2

Electronic spectral data of ligand(BTT) and their metal complexes

S.No Complex Couple Epa (v) Epc (v) Ipc (µA) Ipa (µA)

1. [Cu L2]Cl2Cu(III)/Cu(II) 0.325 0.15 0.25 0.65

CYCLIC VOLTAMMETRIC DATA OF COPPER COMPLEX

Complex A A Aiso g g giso

[Cu L2Cl2] 160.0 82.05 160.42 2.85 2.29 2.286

ESR Spectral Data of Copper and Complex in DMF at 77 K

Complex A A Aiso g g giso

[Cu L2Cl2] 160.00 82.05 160.42 2.85 2.29 2.286

ESR Spectrum of Copper Complex (CuL2)at 300 k

Nuclear Magnetic Resonance 1H NMR spectra of the ligand in CDCl3 shows following signals.

The signals due to aromatic at δ=7.3- 7.8 to showed fine structure CH=N azomethine proton at 8.08 ppm S-H protons appears as singlet in the down field region at 11.8ppm.

13C NMR spectra of the ligand in CDCl3 shows following signals.

The signals due to aromatic at 127-133 ppm showed fine structure C=N azomethine carbon at144 ppm C-SH Carbon appears as singlet in the down field region at178.6 ppm

Proposed structure of metal complex

Three Dimensional View of Metal Complexes

Spectral and magnetic moment

measurement studies reveals that the

ligand behaves as a bidentate ligand and

form metal(II) complexes with octahedral

geometry. The ESR spectral data also are

in supportive of the above octahedral

geometrical environment.

CONCLUSIONS

Dr.A.Thamarai selvanDr. M. Ganasan Dr .P. Tharmaraj Mrs. R . Shunmugakala Prof. A. Elangovan J.Athilakshmi, M. Manikkavalli B.Waheedha Banu and S. Priya My parents and my sister

Jeevitha

ACKNOWLEDGEMENTS

Jeevika Alagan