Pt/Pd–Ethynyl Bond Containing Fluorescent Molecular Architectures as Sensors for Nitroaromatics - Molecular Self-Assembly: Advances and Applications - page 260

supramolecular structure can be predicted, and therefore, design
strategies can be formulated [2,4-10,18]. So, self-assembling of
predesigned building blocks can be made thermodynamically
convergent toward the well-defined architecture via appropriate
choice of acceptors and donors and thus in fewer number of steps
compared to the conventional stepwise covalent synthesis, one
can have relatively defect-free, self-healing assemblies of high
structural integrity. Square-planar Pd

II II

have long been
the favorite choice of metals in this area because of their rigid
square-planar coordination environment, and thus it is easy to
engineer and predict the geometries, shapes, and sizes of the final
assemblies [3,12-17,32]. One of the most interesting features of
this directional coordination-driven self-assembly is that one
can attune the various properties of the metallasupramolecular
assemblies by simply introducing the required functionalities in
the form of different functional groups. As the properties of the
assemblies are guided by the functional groups, incorporation
of various functional groups can prove to be an interesting and
challenging area of research in supramolecular chemistry. Several
functional groups like porphyrin, calixarene, carborane, and acid-
based receptors have been incorporated into various assemblies.
Some of these architectures display interesting properties and
have potential applications in various fields including host-guest
chemistry, catalysis, and photo and electrochemical sensing.
Among the several kinds of linkers used to design polynuclear
transition metal complexes, those that contain ethynyl spacers in
the backbones have been shown to be good members to design
a variety of assemblies with potential applications in optical
electronics. Incorporation of ethynyl functionality into Pt-based
nanoscopic architectures develops fluorescence behavior in the
resulting assemblies and thus there may be a possibility of using
them as fluorescent sensors. Such fluorescent sensors may prove
to be immensely important in the field of trace analyte detection
and thus accordingly gain importance for security purposes like
nitroaromatic explosive sensing and detection.
Thus, in this chapter we will be discussing some ethynyl
containing 2D and 3D self-assembled molecular architectures that
have been found to be effective in the field of chemical sensing such
as detection of biologically relevant analytes like various cations and

and Pt