Structural, magnetic, thermal, mesomorphic and density functional theoretical studies of complexes of copper(II) and iron(II) with carboxylate ions and 2,2’-bipyridine ligands / Lailatun Nazirah Ozair
This research is focused on the syntheses and characterization of magnetic, thermally stable and mesomorphic complexes of copper(II) and iron(II) of general formula [Cu2(RCOO)4(bpy)2] and [Fe(RCOO)2(bpy)] (R = CH3(CH2)6-14, p-CH3(CH2)9-15C6H4; bpy = 2,2’-bipyridine), respectively, and study their...
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| Format: | Thesis |
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2016
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| Online Access: | http://studentsrepo.um.edu.my/6797/ http://studentsrepo.um.edu.my/6797/1/lailatun.pdf |
| Summary: | This research is focused on the syntheses and characterization of magnetic, thermally
stable and mesomorphic complexes of copper(II) and iron(II) of general formula
[Cu2(RCOO)4(bpy)2] and [Fe(RCOO)2(bpy)] (R = CH3(CH2)6-14, p-CH3(CH2)9-15C6H4;
bpy = 2,2’-bipyridine), respectively, and study their magnetic properties (for the
copper(II) complexes) and structures (for the iron(II) complexes) by density functional
theories (DFT). The structures of ligands and complexes were deduced by CHN
elemental analyses, 1
H-NMR spectroscopy (for ligands), FTIR spectroscopy, UV-vis
spectroscopy, and X-ray crystallography (for single crystals). The magnetic
susceptibilities of complexes were determined at room temperature by the Gouy
method, their thermal stabilities by thermogravimetry (TG), and their mesomorphic
properties by differential scanning calorimetry (DSC) and polarizing optical microscopy
(POM). The geometry optimization and frequencies calculations were done using
Gaussian09W package with DFT B3LYP method and 6-31G basis set. A total of nine
copper(II) complexes and eight iron(II) complexes were successfully synthesised and
characterised. All copper(II) complexes have square pyramidal Cu(II) centres with
monodentate and syn-anti bridging carboxylato ligands, were magnetic, thermally stable
(Tdec ranged from 173 o
C to 272 o
C), and mesomorphic. All iron(II) complexes were
octahedral with a mixture of high spin (HS) and low spin (LS) iron(II) atoms at room
temperature, and thermally stable (Tdec ranged from 152 o
C to 160 o
C). The
alkylcarboxylate complexes, except for [Fe2(CH3(CH2)10COO)4(bpy)], were not
mesomorphic,. The arylcarboxylate complexes were mesomorphic. The molecular
modelling for copper(II) complex (1) and iron(II) complexes (6 and 16) showed good
agreement between the experimental and theoretical data. |
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