Author(s):
Pedras, Bruno André Cunha de Vallêra Jacques
Date: 2011
Persistent ID: http://hdl.handle.net/10362/9684
Origin: Repositório Institucional da UNL
Description
Dissertação apresentada para a obtenção do Grau de Doutor em Química Sustentável, especialidade de Química-Física Inorgânica, pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia The work presented in this thesis, which has as its central subject the synthesis and applications of new fluorescent chemosensors and probes, can be divided in two major groups. The first one deals with Schiff base-derived fluorescent chemosensors, with application in the detection of metal cations, and the second group concerns the development of new Ru(II) polypyridyl luminescent molecular probes for DNA.
Before the description and discussion of the performed work, a general introduction is presented in Chapter I, where emphasis is put on the applications of molecular fluorescence to chemical sensing, in order to obtain a better understanding of the photophysical processes that underlie molecular recognition. This connection
is made by defining concepts and giving examples when necessary. A brief mention
to the studied analytes and the instrumental methods used both in developing the
chemosensors and in their applications is also made.
In Chapter II, two new chemosensors possessing crown ether moieties linked
through a Schiff base to a bithiophene group are presented. These systems were synthesized and fully characterized, and their application in the sensing of Ni(II),
Pd(II), Hg(II) and Na(I) was tested by absorption and emission spectroscopies, and
MALDI-TOF MS.
Chapter III describes two new pincer-type ligands, in which a thiophene unit is
linked through a Schiff base either to pyrene or naphthalene chromophores. Sensing
applications for Ni(II) and Pd(II) were investigated by different techniques, and solid complexes with the aforementioned metals were also synthesized.
A new tripodal ligand derived from indole and containing three Schiff base groups is introduced in Chapter IV, and its complexes with Zn(II), Cu(II), Ni(II), Hg(II) and Pd(II) are also described. Metal ion titrations of the free ligand with the
respective metal salts have been performed, helped by DFT calculations, in order to
investigate the role of the central tertiary amine in metal coordination.
The search for new luminescent molecular probes to be used in DNA binding is the subject of Chapter V, in which a new family of six Ru(II) polypyridyl complexes is synthesized. The relation between their structure and the binding mode to DNA is
studied by absorption and steady-state emission spectroscopies, as well as by timeresolved experiments.
Document Type
Doctoral Thesis
Language
English
Advisor(s)
Espiño, Carlos; Avilés, Teresa; Capelo, José