|Abstract: ||This work reports on the design, synthesis and characterization of novel anilate-based
functional molecular materials showing magnetic and conducting properties.
The family of anilate ligands comprises several derivatives obtained by introducing various
substituents (H, F, Cl, Br, I, CN, Me, NO2, etc.) at the 3 and 6 positions of a common 2,5-dihyroxy-
1,4-benzoquinone framework. Their electronic/structural features, coordination modes and
ability to mediate magnetic exchange interactions between coordinated metal centers make
them suitable candidates for the preparation of the above-mentioned materials.
In Chapter 1, the syntheses of novel anilate-based ligands (anilate = An) having thiophene (Th),
3,4-ethylenedioxy-thiophene (EDOT), or Cl/CN as substituents are presented, along with their
crystal structures, the investigation of the emission (Cl/CN derivative) or charge-transfer (Th,
EDOT derivatives) properties and preliminary coordination chemistry studies.
Chapter 2 reports on a general synthetic strategy to achieve rationally designed tris-chelated
octahedral paramagnetic metal complexes, based on the combination of CrIII and FeIII as metal
ions with chloranilate, bromanilate, iodanilate, hydranilate and chlorcyananilate as ligands.
The crystal structure analyses, spectroscopical and electrochemical features, density functional
theory calculations, and the magnetic properties of these metal complexes of general formula
[A]3[MIII(X2An)3] (A = (n-Bu)4N+, (Ph)4P+; MIII = Cr, Fe; X = Cl, Br, I, H, Cl/CN) are described.
In Chapter 3 a novel class of molecule-based ferrimagnets formulated as [A][MnIIMIII(X2An)3] (A
= [H3O(phz)3]+, (n-Bu)4N+; MIII = Cr, Fe; X = Cl, Br, I, H), obtained according to the “complex-asligand”
approach by combining MnII metal ions with the [M(X2An)3]3- molecular building blocks
described in Chapter 2, is reported. The crystal structures and the magnetic properties for
these compounds are described, and the structure/properties correlation observed between
the ordering temperature values and the electron density on the ligand ring, associated with
the electron withdrawing properties of the X substituents, is particularly highlighted.
Chapter 4 reports on the structural diversity and the physical properties of three new
paramagnetic molecular conductors obtained combining the BEDT-TTF organic donor and the
[Fe(Cl2An)3]3- metal complex as conducting and magnetic building blocks, respectively. The
correlation between the crystal structure and conductivity behavior is reported.
Finally, in Chapter 5, the crystal structures and the physical properties of a complete series of
isostructural chiral molecular conductors obtained by combining the TM-BEDT-TTF organic
donor in its (S,S,S,S) and (R,R,R,R) enantiopure forms, or their racemic mixture (rac), with 2D
heterobimetallic anionic layers obtained in situ by association of tris(chloranilato)ferrate(III)
metal complexes and potassium cations are described.
As far as the framework of the thesis is concerned, this work is organized as follows. Part I
contains a general introduction on molecular materials, the state of the art and the aim of the
work. Part II contains the obtained results and their discussion divided in 5 Chapters whose
content has been summarized above. Part III contains the conclusions and the perspectives for
this work. Finally, Part IV contains 5 Appendixes where additional information (basic principles
of conductivity and magnetism, details on the electrocrystallization technique, etc.) are given.|