Abstract
This paper is an overview concerning the preparations and properties as well as possible applications of neutral (one component) metal 1,2-dithiolenes (and selenium analogues). The structural, chemical, electrochemical, optical and electrical behavior of these complexes depend strongly on the nature of ligand and/or the metal. The results of unsymmetrical in comparison to those of symmetrical complexes related to the properties of materials in the solid state are primarily discussed. The optical absorption spectra exhibit strong bands in the near IR spectral region ca. 700 to ca. 1950 nm. X-ray crystal structure solutions show that the complexes usually have square-planar geometry with S–S and/or M–S contacts. Some of them behave as semiconductors or conductors (metals) and are stable in air. The cyclic voltammograms at negative potentials are different from the corresponding potentials of tetrathiafulvalenes (TTFs). As a consequence, the LUMO bands occur at much lower levels than those of TTFs. Consequently, electrical measurements under conditions of field effect transistors exhibit n-type or ambipolar behavior. Illumination of materials with high power lasers exhibits non-linear optical behavior. These properties enable metal 1,2-dithiolene complexes to be classified as promising candidates for optical and electronic applications, (e.g., saturable absorbers, ambipolar inverters).
Highlights
During the last five decades, a number of regular papers, review articles and chapters in books, concerning the synthesis and properties of metal 1,2-dithiolene (M 1,2-DT) complexes and selenium analogues, with M = Ni, Pd, Pt, Au, Cu, etc., have been published
Since the observation of semiconducting behavior in (Li)x[Pt(mnt)2] [5] and (Bu4N)x[Ni(dmit)2] (1 > x > 0) ([6] and references therein), a number of similar complexes based on Ni, Pt, Pd, Cu and Au have been prepared and studied
Dithiolene ligands could be coordinated as 1,2-enedithiolate dianions, neutral dithioketones or mixed valence thioketones—radical thiolate monoanions—and have been regarded both as innocent and non-innocent ligands [6,7,8,9,10,49,68]
Summary
A number of symmetrical M 1,2-DT complexes based on extended TTF-dithiolato ligands, such as [Ni(dt)2] [22,23] and some unsymmetrical such as [Ni(dt)(dmit)] [48,49] (Figure 6) and selenium analogues have been prepared and studied. Dithiolene ligands could be coordinated as 1,2-enedithiolate dianions (as in Tables 1–3), neutral dithioketones or mixed valence thioketones—radical thiolate monoanions—and have been regarded both as innocent and non-innocent ligands [6,7,8,9,10,49,68] These single component (neutral) complexes exhibit semiconducting or metallic behaviour. This paper is an overview of the published work concerning the preparation, properties and possible applications of semiconducting neutral (single component) complexes based on Ni, Pt, Pd, Cu, Au and on some ligands of Tables 1–3. They concern properties of TTFs [117,130,131,132,133], structural [115,123], and electronic [118,119,120,121] properties of solids, electrochemical aspects [122], saturable absorbers [121] and field effect transistors [116,124,125,126,127,128,129,134,135,136,137,138]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
