Coordination compounds aromatic complexes

Planar coordination compounds with aromatic ligands, especially those having extended 7r-systems, show 7r-7r interactions in the solid state. The ligands shown in Figure 8 form complexes with silver(I) which have a supramolecular structure through 7r-7r interactions.586-596... 

Complexes of SB (73) are five-coordinate in solution and normally show no tendency to coordinate a basic ligand to form six-coordinate compounds.725 The formation of adducts depends on the chelate ring, as in (70). With electronegative groups in the aromatic ring, e.g. 5-N02salen (73 RI = R2 = H, R = 5-N02), electronic and CD spectra show hexacoordinate adducts, and solid adducts were obtained with py and DMSO.725... 

Dimercury(I) n complexes are formed between aromatic compounds and Hg2(AsF6)2 in liquid S02 as solvent.113,121 Insoluble complexes with the ratio arene Hg2+ = 1 1 (arene = benzene, naphthalene, 2-methylnaphthalene, 2,6-dimethylnaphthalene, acenaphthene, fluor-anthrene, phenanthrene, anthracene, 9,10-dimethylanthracene or 1,3-dinitrobenzene) or 1 2 (arene = 9,10-benzophenanthrene) have been characterized by elemental analysis and, in some cases, by Raman spectrometry.113,120 The 13CNMR data allow the estimation of formation constants for the hexamethylbenzene, p-xylene and 1,4-dichlorobenzene complexes together with the chemical shifts for the bound substrates in these cases.121 Probably the coordination compounds of dimercury(I) salts with carbazole, dibenzofuran and diben-zothiophene are also n complexes.122... 

Coordination Compounds. Palladium forms numerous complexes with ammonia and with simple amines. Examples are [Pd(NH3)4]2+ [15974-14-8], [PdCl(dien)]+ [17549-31-4], cis-[PdCL (NH3)2] [15684-18-1], and trans-[PdC (NH3)2] [13782-33-7]. Monoammine complexes such as [PdCl3 (NH3)] [15691-32-4] are stable but less common. Examples of aromatic amine complexes include trans- [PdCf (pyr)2] [14052-12-1], [PdCl2(bipy)] [14871-92-2], and nucleosides such as [PdCl(dien)(guanosine)]+ [73601-42-0] (193). Complexes of Pd(IV) such as [PdCl2(NH3)4]2+ [70491-81-5] and [PdCl4(bipy)] [57209-01-5] may be prepared by chlorine oxidation of the corresponding Pd(2+). The aromatic amine Pd(IV) complexes are more stable than ammine and aliphatic amine species, which are reduced to Pd(II) in water or thermally (194). 

Many PSPs are composed of probe dyes, such as polycyclic aromatic hydrocarbons (e.g., pyrene) and coordination compounds (e.g., platinum por-phryins and ruthenium(II) polypyridyl complexes) immobilized in various gas permeable polymer films such as silicon polymer, organic glassy polymers (e.g., poly(methylmethacrylate), polystyrene), fluorinated polymers, or cellulose derivatives such as ethyl cellulose [9,10]. As probe molecules interact with polymer matrices directly, the properties of PSPs strongly depend on the properties of polymer matrices. The oxygen permeability of polymer matrix is an especially important factor for highly sensitive PSP. 

As a result of interaction of 843 and pyridine, the adduct 845 is formed [53], The structures of coordination compounds 844 and 845 were proved by x-ray diffraction. As shown above (Sec. 3.4.3.2), the direct ammonia synthesis [55,56] with participation of various ligands (especially aliphatic, aromatic, and heterocyclic amines, aminoalcohols), elemental metals (or their oxides), and NH4SCN in mostly non-aqueous media, opens definite possibilities for obtaining thiocyanate complexes. In this respect, transformation (4.9) should be mentioned [57] ... 

Additionally to the theoretical data and synthetic techniques for various metal complexes presented in Chaps. 2-A, we would like to pay special attention to three kinds of coordination compounds (complexes of phthalocyanines, quinones, and radioactive elements), whose syntheses, in our opinion, have been insufficiently generalized in monographs and textbooks on synthetic coordination chemistry. This choice is caused by the facts that phthalocyanines, as n-aromatic macrocyclic compounds, possess unusual thermal stability (nonstandard for organic and organometallic species) the quinone complexes have free-radical properties and coordination and organometallic compounds of radioactive elements are interesting at least for the reasons of necessity of special precautions in their syntheses and applications in the nuclear industry and nuclear medicine. So, this chapter is dedicated to the peculiarities of structure and properties and the main synthetic procedures for the complexes above. 

Thermodynamic aspects of 1,3-diborolanes, 2,3-dihydro-l//-l,3-diboroles, 1,3-azaborolidines, 2,3-dihydro-l,3-thia-boroles 2,3-dihydro-l//-l,3-stannaboroles, or 2,3-dihydro-l//-l,3-silaboroles are only sparsely mentioned. It has been found that the 127t-electron antiaromatic heterocycle 23 is stabilized by electron delocalization via the boron atom (cf. compound 9) <2002ZN1125>. Noteworthy is the comparison between the 8jt-electron antiaromatic 2,3-dihydro-l,3-benzothiaborole 24 or 4jt-electron antiaromatic 2,3-dihydro-l,3-thiaborole 26 and the corresponding lOtt-electron 25 or 67t-electron 27 aromatic lithium compounds, the latter forming stable Jt-coordinated transition metal complexes. 

Various first-generation dendrimers and star-shaped molecules were generated from the nucleophilic aromatic substitution of chlorosubstituted arenes coordinated to cyclopentadienyliron complexes (Schemes 2.68 and 2.69). These compounds contained either ether or ester bridges. The star-shaped molecules prepared with ether bridges showed a decrease in solubility with an increase in star size, whereas the incorporation of ester bridges resulted in a decrease... 

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