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Hamid Khanmohammadi

Hamid Khanmohammadi

Academic rank: Professor
ORCID: https://orcid.org/0000-0001-5600-4738
Education: PhD.
ScopusId: 22734138900
Faculty: Science
Address: Arak University
Phone:

Research

Title
Synthesis, X-ray Characterization, NMR and ab initio Molecular-Orbital Studies of Some Cadmium(II) Macrocyclic Schiff-Base Complexes with Two 2-aminoethyl Pendant Arms
Type
JournalPaper
Keywords
Cadmium(II) Complexes, Schiff-base Macrocyclic ligand, Pendant arm, Seven coordinate, ab initio Studies
Year
2004
Journal Journal of the Iranian Chemical Society
DOI
Researchers Hassan Keypour ، Hamid Khanmohammadi ، Kevin P. Wainwright ، Max A. Taylor

Abstract

Three new pendant arm Schiff-base macrocyclic complexes, [CdLn]2+ (n = 5, 6, 7), have been prepared via cyclocondensation of 2,6-diacetylpyridine with three different branched hexaamines in the presence of Cd(II). The ligands are 15-, 16- and 17-membered pentaaza macrocycles having two 2-aminoethyl pendant arms [L5 = 2,13-dimethyl-6,9-bis(aminoethyl)-3,6,9,12,18-pentaazabicyclo[12.3.1]octadeca-1(18), 2, 12, 14, 16-pentaene, L6 = 2,14-dimethyl-6,10-bis(aminoethyl)-3,6,10,13,19-pentaazabicyclo[13.3.1]nonadeca-1(19), 2, 13, 15, 17-pentaene and L7 = 2,15-dimethyl-6,11-bis(aminoethyl)-3,6,11,14,20-pentaazabicyclo[14.3.1]eicosa-1(20),2,14,16,18-pentaene]. All complexes were investigated by IR, 1H and 13C NMR, COSY(H, H) and HETCOR(H, C) spectroscopy and X-ray diffraction. In the solid state structure of each complex the Cd(II) ion is situated centrally within an approximately planar pentaaza macrocyclic ring, binding to the five nitrogen atoms, and also to the two pendant amines which are located on opposite sides of the macrocyclic plane. ab initio HF-MO calculations using a standard 3-21G* basis set have been used to verify that these same basic structures correspond to energy minima in the gas phase.