| dc.description.abstract | Synopsis of the thesis entitled “Aspects of the chemistry of copper(II)
complexes having different nuclearity” to be submitted by Mrs. K. Geetha
under the supervision of Prof. A. R. Chakravarty of the Department of
Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore –
560 012 for the Ph.D. degree in the Faculty of Science.
The chemistry of mono-, di- and polynuclear copper(II) complexes is of
importance towards understanding the structural, electronic and magnetic properties of
the active sites of several copper-containing metalloproteins. This thesis deals with the
syntheses of monomeric, dimeric and high nuclearity copper(II) complexes and the
study of their magneto-structural properties.
Asymmetrically di- and tribridged dicopper(II) complexes having a
[Cu?(OR)(O?CR)?]?? (m = 1, 2; n = 2, 1) core viz. [Cu?(OH/OMe)(O?CPh)?(tmen)?]
(PF?) (1), Cu?(OH)(O?CPh)?(tmen)? (2), Cu?(OH)(O?CC?H?-p-
Me)(tmen)?? (3) and Cu?(OH)(O?CC?H?-p-OMe)(tmen)?? (4) have
been synthesized. X-ray crystallographic studies (Chapter II) of these complexes were
made and a magneto-structural correlation (Chapter III) has been obtained. A
tribridged dicopper(II) complex Cu?(O?CC?H?-p-Me)?(tmen)? (5) has been
obtained from a similar reaction at 0 °C using copper(II)-p-methylbenzoate as a
precursor complex. Complex 5, however, magnetochemically behaved like a
dibridged complex. The X-ray structure and other physico-chemical properties of
complex 5 are presented in detail in Chapter IV.
The reactions of tetraarylcarboxylatodicopper(II) complexes having electron-
withdrawing substituents at the para position of the benzoic acid with tmen resulted in
the formation of monomers of composition [Cu(O?CC?H?-p-X)?(tmen)] (6–8). The
X-ray crystal structures and properties of these complexes were studied in detail
(Chapter V). The interesting feature of these molecules is the observation of
chemically significant C–H...O interactions.
In order to prepare dicopper(II) complexes having alkoxo–carboxylato bridges
with an additional binding site on the carboxylate ligand, a reaction of copper(II)
perchlorate with a pentadentate ligand H?L, derived from the condensation of
salicylaldehyde and 1,3-diamino-propan-2-ol (2:1 ratio), in presence of isonicotinic
acid has been found to produce a novel polymeric copper(II) complex
[Cu?(L)(O?CC?H?N)]? (9). The X-ray structure and its magnetic properties have been
investigated in detail (Chapter VI). The reaction of copper(II) perchlorate with
a different pentadentate Schiff-base ligand (H?L?), obtained from the condensation of
1,3-diamino-propan-2-ol and acetylacetone, in the presence of KOH has been found to
form a novel octanuclear copper(II) complex [Cu?(L?)?(OH)?]·3H?O·C?H?? (10)
which has a hydrophobic exterior and a hydrophilic metallamacrobicyclic core
showing selective hydrogen-bonding interactions. The complex exhibits novel non-
covalent interactions. The X-ray structure and magnetic properties of this complex are
given in Chapter VII. The details of the X-ray crystallographic and magnetic data are
presented in Appendices I–VI of the thesis. | |
