Bromo, and Iodo-complexes

There are many fluorocomplexes of aluminum. The general formula for the fluoroaluminates is M I, I, a I- based upon A1F6 octohedra. which may share comers to give other ratios of A1 F than 1 6. Chloroaluminates of the type M lAlClj] are obtainable from fused melts. Aluminum ions form chloro-, bromo-, and iodo-complexes containing tetrahedral IALX41 ions. However, in sodium aluminum fluoride NaAlF4, the aluminum atoms are in the centers of octohedra of fluorine atoms in which the fluorine atoms are shared with neighboring aluminum atoms. 

For convenience we group chloro, bromo and iodo complexes together no iluoroammines have yet been reported. 

The bromo and iodo complexes can also be prepared from [RhCl(C8H,4)2]2.47 The 31P NMR spectrum shows [RhCl(PCy3)2] to be in equilibrium with [RhCl(PCy3)2]2.46... 

For example, complexes with very strong EPD ligands, such as Ng ", NCS ", CN, or F may exist even in solvents of high DN such as HMPA or DMSO. In solvents of weak or medium EPD properties, complex formation is essentially quantitative. On the other hand, bromo and iodo complexes usually exist only in weak EPD solvents, such as NM, PDC, or AN, and are completely ionized in solvents such as DMF, DMSO, or HMPA. The stabilities of chloro complexes are somewhat higher in the respective solvents. According to Table VII the chloride ion has an EPD strength similar to that of DMF or DMSO. Consequently chloro complexes in these solvents (compare Table IV) are ionized to some extent, sometimes with autocomplex formation. 

It is convenient to discuss protactinium(IV) and (V) bromo and iodo complexes together since they have only been prepared by reacting together the component halides in anhydrous methyl cyanide (40, 46, 48). Thus NMe4PaBrg, NEtiPaBrg, and PhgMeAsPala are isolated (40,46) by removal of solvent in vacuo at room temperature. Hexabromo-niobates(V) and tantalates(V) have been prepared in a similar manner (46). Attempts to obtain octabromo complexes for these three elements have been unsuccessful. The orange hexabromoprotactinates(V) are... 

WEAK AND UNSTABLE ANIONIC BROMO AND IODO COMPLEXES... 

Complexes of relatively strongly oxidizing metal ions with the more reducing halide ions are not prepared easily because the halide ion is oxidized by the metal ion. The low-temperature (< 25°) method discussed here allows the preparation of bromo and iodo complexes of oxidizing metal ions which could not be prepared by other means. The complex is formed directly as a solid salt in which crystal-lattice energy gives stability. 

Although in theory it should be possible to prepare almost all anionic bromo and iodo complexes by this method, the real value of the method lies in the preparation of those complexes that cannot be made by other methods or can be made only with difficulty. The increased reactivity, due to the very fine crystal size of the products obtained by this method, probably makes it desirable that bromo and iodo complexes which are easily prepared from solutions be made in that manner. Typical examples of bromo and iodo complexes which can be prepared by this method are discussed here. 

A wide variety of anionic actinide halide complexes are well known and typically are isolated with alkali or alkahne-earth metal ions. The tendency and stability of the anionic complexes follow the trend F Cl > Br I. The trivalent fluorides and chlorides typically form complexes of the form AnX4 and AnXe ". Plutonium has also been shown to give the following complexes PuCb ", Pu2Cl7, and PuClg . The anionic tetravalent actinide fluorides represent a broad class of complexes, for example, M AnFj, (x = 1, y = 5 x = 2, y = 6 V = 3, y = 7 x = 4, y = 8). Tetravalent actinide chloro, bromo and iodo complexes can be isolated from aqueous solutions in the form of octahedral AnCle " ions. 

CV = cyclic voltammetry M = magnetic studies. Bromo and iodo complexes also known. 

Bromo and iodo complexes also known. Chloro, bromo and iodo complexes also known. Bromo and iodo complexes known, also with arsine and stibine ligands. Methoxo and fluoio complexes also known. ... 

Bromo and iodo complexes and Irani isomers also known. L = isonicotinamide. Also PEt, PMePhj, PEtjPh, PEtPhj, PPr jPh,... 

Di-/i-chloro-bis[(t -pentamethylcyclopentadienyl)chlororuthenium(III)], [Cp RuCl2]2 (1) is the general entry into Cp (t -C5Me5) Ru sandwich and half-sandwich chemistry and has been used in numerous transformations since its introduction in 1984. It is easily prepared according to Eq. 1. Analogous bromo and iodo complexes are obtained by halide exchange with NaX in MeOH." ... 

The formations of chloro, bromo and iodo complexes have been studied. Recently, electrochemical methods have been used to measure equilibrium constants for the formation of chloro (0.086), bromo (1.1 x 10 ) and iodo (1.1 x 10 ) complexes of diromium(III). ... 

M = magnetic studies CV = cyclic voltammetry, isonic = ironicotinamide, Also bromo and iodo complexes. 

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