Metal-containing macrocycles,

Extended conjugated systems of jr-electrons make these compounds promising candidates for various elecfronic devices [49, 50] and solar cell compo-nenfs [51,52]. These macrocycles provide a variefy of subsfifufion sifes which can be used fo create compounds with controlled electron donor/acceptor properties [53, 54]. In nature, metal-containing macrocycles are present as central structural units in many substances involved in biochemical redox reactions [55]. 

A comparison of different metal-containing and metal-free macrocycles showed that the metal centers seem to stabilize the tetrapyrrole core [104, 128, 144]. As a result, the second decomposition step is shifted to much higher temperatures compared to the metal-free porphyrin and the overall mass loss is much smaller, as it becomes apparent from Fig. 16.14. Furthermore, the mass fragments related to the decomposition of the tetrapyrrole core (HCN) are detected at significantly higher temperatures in the coupled mass spectrometer for metal-containing macrocycles compared to the metal-free ones [104, 112, 128,144],... 

A number of dithiocarbamates derived from diamines have been prepared, including those based on a terphenyl backbone, which have utilized these ligands toward the self-assembly of large metal-containing macrocycles upon addition of metal acetates (1468,1469). For example, macrocyclic complexes (347) have been prepared in this manner. 

Strange enough, so far there are no books entirely devoted to condensation TPEs and the latter are considered only in chapters of more general works. The most important TPEs prepared by polycondensation are the subject of several chapters of this book polyester-based TPEs, poly(amide-6-ethers), polyurethanes, etc. However, some less known condensation TPEs are described in Chapter 2 metal-containing macrocycles as monomers, liquid crystalline side chains, metallo-supramolecular block copolymers, as well as the use of enzymatic catalysis or of microorganisms. 

This book fills an important gap, since for the first time it is entirely devoted to condensation TPEs. The following considerations place landmarks of the new chemistry in this field, rather than browsing the recent improvements of the well established TPEs. Several new techniques appeared quite recently they are already patented, if not applied, and are very promising. This is the case of the metallo-supramolecular block copolymers [189], which result from the chelation of complexing group end-capped oligomers with different metal derivatives and the homopolymers and copolymers prepared from metal-containing macrocycles [190,191]. 

Block copolymers prepared from metal-containing macrocycles... 

The presence of the cyclic backbone in ligands of this type makes a substantial contribution to their metal-ion complexing ability even though coordination involves donors which are not directly incorporated in the ring fragment. The origins of the enhanced stability of the metal-containing species may be considered to reflect the operation of an indirect macrocyclic effect (see Chapter 6) in these systems. 

Metalated container molecules can be viewed as a class of compounds that have one or more active metal coordination sites anchored within or next to a molecular cavity (Fig. 2). A range of host systems is capable of forming such structures. The majority of these compounds represent macrocyclic molecules and steri-cally demanding tripod ligands, as for instance calixarenes (42), cyclodextrins (43,44), and trispyrazolylborates (45-48), respectively. In the following, selected types of metalated container molecules and their properties are briefly discussed and where appropriate the foundation papers from relevant earlier work are included. Porphyrin-based hosts and coordination cages with encapsulated metal complexes have been reviewed previously (49-53) and, therefore, only the most recent examples will be described. Thereafter, our work in this field is reported. 

III. Metalated Container Molecules of Binucleating Polyaza-Dithiophenolate Macrocycles... 

Phosphorus-containing macrocycles, 990, 996, 998 macrocychc effect, 1002 ring size, 1003 stereochemistry, 1003 Phosphorus heterocycles transition metal complexes, 1041 Phosphorus ligands, 989-1061 ir-acid series, 1033 bonding, 1030-1041 cone angle concept, 1012 trigonal bipyramidal complexes, 1036 Phosphorus oxychloride metal complexes, 500 Phosphorus ylides transition metal complexes, 1056 Phosphorylation biological, 978 Phosvitin, 975 Photochromism... 

Nitrogen-containing macrocycles are highly complementary for first row transition metals as in the examples shown in Section 1.6. Common azamacrocycles include cyclen ([12]ane-N4) and cyclam (3.45) and many have a history that significantly pre-dates the crown ethers. Unlike the crown ethers which do not have donor atom substituents, the binding constants of azamacrocycles such as cyclam are greatly affected by N-alkylation. Alkylated amines are significantly more basic than ammonia, for... 

In the [2]catenate, the circumrotation of the terpyridine-containing macrocyclic component can be reversibly controlled 21,22 (Figure 5), by altering the redox state of the metal. The absorption spectrum of a red-brown solution of [5 Cu] BF4 in MeCN shows a band, centered on 437 nm, characteristic of a Cu+ ion tetracoordinated to two phenanthroline ligands. Upon oxidative electrolysis, or upon addition of Br2, Cu+ is oxidized (step 1 in Figure 5) to Cu2+ and the solution turns deep green. The absorption spectrum shows a band, centered on 670 nm, typical of a Cu2+ ion tetracoordinated to two phenanthroline ligands. However, this absorption band shifts to... 

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