Phthalocyanine complexes electrochromic

The electrochromism of the phthalocyanine ring-based redox processes of vacuum-sublimed thin films of [Lu(Pc)2] was first reported in 1970,32 and since that time this complex has received most attention, although many other (mainly lanthanide) metallophthalocyanines have been investigated for their electrochromic properties.1 Lu(Pc)2 has been studied extensively by Collins and Schiffrin33,34 and by... 

Coordination compounds composed of tetrapyrrole macrocyclic ligands encompassing a large metal ion in a sandwich-like fashion have been known since 1936 when Linstead and co-workers (67) reported the first synthesis of Sn(IV) bis(phthalocyanine). Numerous homoleptic and heteroleptic sandwich-type or double-decker metal complexes with phthalocyanines (68-70) and porphyrins (71-75) have been studied and structurally characterized. The electrochromic properties of the lanthanide pc sandwich complexes (76) have been investigated and the stable radical bis(phthalocyaninato)lutetium has been found to be the first example of an intrinsic molecular semiconductor (77). In contrast to the wealth of literature describing porphyrin and pc sandwich complexes, re-... 

The phthalocyanine containing polymer films were electrochemically investigated for their electrochromic reductions and reoxidations [406,411]. Under irradiation the reduction of O2 to water was studied in photoelectrochemical cells [407,409,412]. Especially Zn(II)-phthalocyanine in poly(vinylidene fluoride) shows high cathodic photocurrents. Also the electrochemical carbox dioxide and proton reduction by Co(II)-phthalocyanines in a low concentration monomolecular in a polyvinylpyridine matrix were investigated as part of a photoenergy systems [413,414]. As an active catalyst for proton reduction also a bipyridyl platinum complex in a polymer Nafion membrane was found [415]. In order to construct such a photochemical energy conversion system, the research in this field was extended for the electrocatalytic water oxidation to O2 [416-419]. The Ru-complexes cj5-[Ru(bpy)2Cl2] and especially Ru-red ([(NHsjs Ru >-Ru(NH3)4-0-Ru(NH3)5] ) are active as electrocatalysts. 

Intensive investigations of REM phthalocyanines have led to the foundation of several useful properties of them. These complexes are offered for utilazation as electrodes for electrochemical concentration and isolation of iodine from dilute water solutions [123, 124]. Changing of color of REM phthalocyanines in electric field became the basis for elaboration and preparation of rare earth electrochromic indicators [145, 146] and light filters [122]. 

Among the transition metal complexes, phthalocya-nines have been studied extensively due to their exotic properties, e.g. high thermal stability, photo and electrical responses, etc. Consequently, the studies of the application of phthalocyanine based conductive LB films to gas sensors or electrochromism have been carried out by many groups, although the conductivity of the materials is relatively low compared with other conductive LB films. Highly conductive LB films of this class of material have been mainly obtained using metal(dmit)2 salts. 

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