1,2-Dithiolenes metals

Table 4 Structural characteristics of the metal dithiolene salts of halogenated TTFs... 

Hill, C. A. S. Underhill, A. E. Winter, C. S. Oliver, S. N. Rush, J. D. Resonance Enhanced Third-order Nonlinearities in Metal Dithiolenes. In Organic Materials for Nonlinear Optics II Hann, R. A., Bloor, D., Eds. Royal Society of Chemistry London, 1991, pp 217-222. 

Keywords Donor type metal complexes, Metal dithiolene complexes, Molecular conductors, Organometallic complexes, Unsymmetrical metal complexes... 

General Features of Unsymmetrical Components Based on Organometallic Metal-Dithiolene Complexes... 

In this section, we will focus only on compounds based on M(dmit)2 anions and (Cp 2Mn)+, since Gama and Almeida also report on metal-dithiolene containing compounds with metalloceniums in Chapter (see pp. 97-140). 

The cyclic voltammograms of the metal-dithiolene capped porphyrazines 147-149, 152, and 153 reveal a reversible oxidation couple arising from the peripheral [N2-M-S2] functionality, formally written as M(nyni) (M = Pt, Pd) (29). These oxidations occur at approximately +0.2 V (vs Fc+/Fc) for the Pd(bdt) (148), Pd(dmid) (149), Pt(tdt) (152), and Pt(dmit) (153) capped porphyrazines, respectively (Table XXVII). However, all... 

We will conclude the present section with a further class of metal-dithiolenes, namely [M(R2timdt)2] (R2timdt= 1,3-dialkylimidazoline-2,4,5-trithione monoanion), Scheme 10.84... 

Synthesis AND Structural Characterization of Thiophene-Functionalized Metal Dithiolenes... 

Herein, we will review the preparation and study of this class of functionalized metal dithiolenes, with particular emphasis on the relationships between functionality and solid-state structure, and the overall effect on material properties. Discussion will go beyond the application of this class of thiolene complexes as molecular materials, and equal attention will be given to the effectiveness of various structural motifs when designing these species as polymeric precursors. 

Chart 1. Metal dithiolenes and other common building blocks of molecular-based conductors. 

Synthesis. The first known thiophene-based metal dithiolenes were reported by Gol dfarb and Kalik in 1968." These consisted of the nickel and copper complexes of 2,3-thiophenedithiolate produced from ethyl 3-thienyl sulfide as shown in Scheme 1. Both complexes were reported as black, high melting solids and were thought to be the neutral bis(2,3-thiophenedithiolate) species. 

Synthesis. In attempts to further extend the 7i-system of the metal dithiolene core of 2a, Amb and Rasmussen reported the preparation of a 2,2 -bithiophenedithiolate ligand to synthesize [Bu4N][4a] (Seheme 3) in 2007. The resulting anion 4a represents a funetionalized analogue of 2a, with the %-system extended through the a-thienyl groups coupled to the exterior a-positions of the 2a core. This initial synthetic approach was then optimized and used to produce a series of extended metal thiophenedithiolene eomplexes 4a-e as shown in Scheme 3. ... 

Scheme 6. Synthesis of metal dithiolenes containing pendent thiophenes.

The nonplanar nature of 11 hinders intermoleeular contacts between the metal dithiolene complexes. Thus, there are few intermoleeular interactions between the anions within [Et4N][ll], although short C-H -S contacts of 2.906 A are observed between the pendent thiophenes of neighboring anions (Figure 13A). In contrast, the more planar structure of 12 allows significant jt stacking of the complexes to form columns with a face-to-face distance of 3.7 A (Figure 13B). ... 

A main focus of preparing metal dithiolenes functionalized with thiophene units has been for their incorporation into conjugated organic materials. On first glance, it would seem that the combination of metal dithiolenes and conjugated polymers could produce attractive new materials for use in such applications as field effect transistors and NIR optical materials. However, several challenges remain before these materials can be applied to useful... 

Chapter 2- Transition metal dithiolenes are versatile complexes eapable of a wide range of oxidation states, coordination geometries, and magnetie moments. As a eonsequence, these complexes have been widely studied as building bloeks for erystalline molecttlar materials. Particularly successful are the square-planar metal dithiolenes (Chart 1), from which materials have been produeed that exhibit condueting, magnetic, and nonlinear optieal properties, as well as supereonduetivity in some cases. " In their application to molecular- based... 

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