Synthesis and characterisation of [CU2(P-H2NC6H4COO)N(Rcoo)4-N] as low temperature functional metallomesogens / Ahmad Nazeer bin Che Mat

Author

Che Mat Ahmad Nazeer

Date of Award

1-1-2011

Thesis Type

masters

Document Type

Thesis

Divisions

science

Department

Dept of Chemistry

Institution

University of Malaya

Abstract

This research project is focused on the synthesis and characterization of copper(II) mixed carboxylates of general formula, [Cu2(RCOO)n(R’COO)4-n)], where R = p-H2NC6H4, R’ = CH3(CH2)14, and n = 1–3. These mixed carboxylates were specially designed to be low-temperature and thermally stable magnetic and redox-active metallomesogens. A total of six binuclear copper(II) mixed-carboxylates were successfully prepared by the one-pot reaction, and their thermal, metallomesogenic, magnetic and redox properties reported. The instrumental analyses used to characterize these complexes were CHN elemental analyses, FTIR and UV-vis spectroscopies, molar conductivity, thermogravimetry, differential scanning calorimetry, optical polarized microscopy, magnetic susceptibility by the Gouy method, and cyclic voltammetry. All complexes, except for [Cu2(p-H3NC6H4COO)3Cl]Cl3.NH3.3H2O (Complex 4), were non-electrolytes. Complex 4 was a 1:1 electrolyte. Their geometry was square-pyramidal involving syn-syn or syn-anti bridging and/or chelating carboxylates, their thermal stabilities were higher than 200oC, and the melting point ranges from about 118oC, except for Complex 6 which melted at a higher temperature of 166oC. The complex exhibiting thermotropic metallomesogenic properties was [Cu2(p-H2NC6H4COO)2(CH3(CH2)14COO)2(H2O)(CH3CH2OH)] (Complex 1) with smectic C mesophase. They were either antiferromagnet or ferromagnet, with μeff and 2J values from 2.11 to 3.72 B.M. and from -200 to 109 cm-1, iii respectively. All complexes were redox active. The redox reactions were quasi-reversible involving extensive structural reorganization and chemical reactions (the EC mechanism).

Note

Dissertation Submitted In Fulfillment Of The Requirement For The Degree Of Master Of Science

Recommended Citation

Ahmad Nazeer, Che Mat, "Synthesis and characterisation of [CU2(P-H2NC6H4COO)N(Rcoo)4-N] as low temperature functional metallomesogens / Ahmad Nazeer bin Che Mat" (2011). Student Works (2010-2019). 629.
https://knova.um.edu.my/student_works_2010s/629