MO Calculations of Imine Hydrolysis and Cu Complex Formation.

CHM 6440/7440

Winter 2005

By

Rabab Aoun

Outline

Introduction My Project Reaction Mechanism MO Calculations and reaction energy Substituents Effect

Introduction

Many studies on the hydrolysis of imines in the presence of , and .

Alkaline hydrolysis of the imine anion involves intermolecular general base catalysis.

The effect of stabilizing the aldimine linkage to hydrolytic splitting is maximum for .

Generation of complexed phenoxyl-containing species depends on the presence of substituents at the ortho and para positions of the phenolate ring.

2Cu 2Ni 2Zn

2Cu

My Project

Hydrolysis of imine in the presence

of . Imine hydrolysis by triethylamine and

water. Computational studies investigating all

the parts of the reaction.

2Cu

Imine Hydrolysis Reaction

N

N

O-

+ H2O

O

O-

+ N

H2N

R'

R

HBPIEt-butyl Phenol

Pyridine

OH 2 +

Cu Complex Reaction

Cu2+ + 2

O

O-

Cu

+OO-

O+

-O

2+

Cu Complex Reaction

Cu2+ + 2

O

O-

Cu

+OO-

O+

-O

2+

Mechanism of Hydrolysis

N

R

HR'

OH-

-N

HR'

O

R

HO

H

H

Mechanism of Hydrolysis

N

RH

H

O

R'

H

OH-

HO

H OH-

H2NR

+

+R'

H

O

MO Calculations

Standard ab initio molecular orbital calculations are performed at B3LYP/ 6-31G(d)

Optimization and frequency method calculation

Collection of electronic energy and zero point correction.

Energy

HBPIE -1001.83691895 a.u.

-76.4089533236 a.u.

Reactant -1078.245872 a.u.

t-butyl Phenol -735.282945673 a.u.

Pyridine -342.940914839 a.u.

Product -1078.223861 a.u

Reaction .022011488 a.u

Reaction 13.8 Kcal/mol

MO Calculations of Imine Hydrolysis

OH 2

MO Calculations of Cu complex

Energy

-1639.21308383 a.u.

2( t-butyl Phenol) 2*(-735.282945673) a.u.

Reactant -3163.778975 a.u.

Cu-Complex

(product)

(-3109.78531973 a.u.)

Not Completed

Reaction Not Completed

Cu Monomer and its Radical

Cu Monomer Cu Radical

SCF Energy

(a.u.)

-3109.78531973 -3109.52753697

t-butyl Phenol and its Radical

t-butyl Phenol Radical

SCF Energy

(a.u.)

-735.282945673 -734.999198230

C-O bond length 1.35757 1.30812

Substituent’s Effect on Phenoxyl Complexes

The generation of complexed phenoxyl-containing species depends on the presence of substituents at the ortho and para positions of the phenolate ring.

Unsubstituted phenolates are much less electroactive than those containing bulky electron-donor t-butyl groups.

Current Developing Studies

The chemistry of electroactivity of phenoxyl species is being developed with several di- and trivalent ions in order to evaluate the geometries preferences of the ligands.

References

1. Anadi C. Dash, Bhaskar Dash, and Prasanna Kumar Mahapatra, J. Chem. Soc., Dalton Trans. 1983,1503.

2. Nathan E. Hall and Brian J. Smith, J. Phys. Chem., 1998, 102, 4930-4938.

3. Margaret Brault, Ralph M. Pollack, and Charles L. Bevins, J. Org. Chem., Vol. 41, No. 2,1976

4. Jack Hine, Francis A. Via, Judith K. Gotkis, and John C. Craig, Jr., Journal of the American Chemical Society,1 92:17 / August 26, 1970

Thanks

Dr. Schlegel Dr. Hrant P. Hratchian Marco Mallard Barbara Others