Solid complexes

Polyiodides are specific polyhalides containing species such as I3", I7", Iq". Polyhalides often dissociate on heating the solid complexes. 

Tiianium lII) fluoride, TiF3. Formed Ti or TiHj. plus anhydrous HF at 700 C. Blue stable solid. Complexes containing [TiF ] " ions are known. 

Another important breaktlirough occurred with the 1974 development by Laubereau et al [24] of tunable ultrafast IR pulse generation. IR excitation is more selective and reliable than SRS, and IR can be used in pump-probe experiments or combined with anti-Stokes Raman probing (IR-Raman method) [16] Ultrashort IR pulses have been used to study simple liquids and solids, complex liquids, glasses, polymers and even biological systems. 

To prevent the solid complex from caking (which occurs if the stirring is not sufficiently rapid) about 75 ml. of dry ethylene dichloride may be added. 

This interpretation is supported by literature studies on copper(II) complexes containing two -amino-acid ligands. For N-unsubstituted -amino-acid ligands, deductions as to position of the cis -trans geometrical equilibrium in solution are difficult as illustrated by the fact that for some -amino acids solid complexes have been isolated of both the ds and trans geometry. In contrast it seems as if copper(II) complexes containing two N-alkylated -amino-acid ligands crystallise exclusively in the trans form ". ... 

The materials shown and described above were generally prepared from the nucleophilic phenoxide or alkoxide and the appropriate bromide. The syntheses of a variety of such compounds were detailed in a report which appeared in 1977. In the same report, complex stability and complexation kinetics are reported. Other, detailed studies, of a similar nature have recently appeared" . Vogtle and his collaborators have also demonstrated that solid complexes can be formed even from simple polyethylene glycol ethers . Crystal structures of such species are also available... 

This method is probably the most commonly used one for the cleavage of methyl ethers, because it generally gives excellent yields with a variety of structural types. The solid complex BBr3-Me2S that is more easily handled can also be used. BBr3 will cleave ketals. 

Numerous solid complexes have been crystallized from brown solutions of iodine and extensive X-ray structural data are available. Complexes of the type L—>-I-X and L—>-I-X-t—L... 

The process of separating the intermediate products from the purified solutions, in the form of solid complex fluoride salts or hydroxides, is also related to the behavior of tantalum and niobium complexes in solutions of different compositions. The precipitation of complex fluoride compounds must be performed under conditions that prevent hydrolysis, whereas the precipitation of hydroxides is intended to be performed along with hydrolysis in order to reduce contamination of the oxide material by fluorine. 

The nature of spin state transitions in solid complexes of iron(II) and the interpretation of some associated phenomena. E. Konig, G. Ritter and S. K. Kulshreshtha, Chem. Rev., 1985, 85, 219 (91). 

The experimental details are mentioned as they arise often air must be excluded from the reactions but there are many examples when this exclusion is not important (or may even be fatal ) to the reaction. A general point is that nearly all of these organocobalt(III) complexes are unstable to visible light, and so light should be excluded during the preparations at all times whenever the organocobalt(III) complex is in solution. The solid complexes are stable to visible light. 

Treatment of the A -methylpyridinium salt of (65) with phosphiran gave a solid complex, pentacarbonylphosphiranmolybdenum(O) (66). 

While iron(III) complexes of thiosemicarbazones with different functional groups involving have been prepared from 2-acetylpyridine, substitution on the ring has been more popular with thiosemicarbazones derived from 2-formylpyridine. The only thiosemicarbazones in which the 2-acetylpyridine ring has been substituted are 15a and 15b, prepared from 6-methyl-2-acetyl-pyridine [120]. Both of these iron(III) complexes have rhombic spectra and values of g, are similar to those found for the 2-acetylpyridine thiosemicarbazones. Solution studies have been carried out on the iron(III) complex of 2,6-diacetylpyridine mono-thiosemicarbazone, but the solid complex was not isolated [143]. 

Under favorable conditions, rates of intersystem crossing between HS and LS states for solid complexes may be obtained directly, if a suitable spectroscopic technique is applied. Conditions and details of this method will be discussed in Sect. 8. 

As far as the solid complexes are concerned, the qbove conclusions are generally valid for gradual spin-state transitions, whereas additional features such as hysteresis effects are observed for transitions which show abrupt changes of physical properties. In fact, abrupt transitions seem to be formed if the volume change A V associated with the spin-state conversion of the molecules cannot be conveniently accommodated by the lattice. 

Acyl cations have been detected in a number of solid complexes, in the liquid complex between MeCOCl and A1C13 (by i.r. spectroscopy), in solution in polar solvents, and in a number of cases where R is very bulky. In less polar solvents, and under a number of other circumstances, acyl cations are not detectable, however, and it must be the polarised complex that acts as the electrophile. 

The formation of complexes of the fluorescent tracer dye ammonium 1-phenyl-aminonaphthalene-8-sulphonate (10.41) with cyclodextrins has been investigated with favourable results, especially in environmental studies [33]. The ability of this dye to complex with cyclodextrins has been exploited mainly as an analytical tool in the study of cyclodextrin applications, since its fluorescence is easily measured. The interaction of a-, P-and y-cyclodextrins with azo acid dyes containing alkyl chains of different lengths has been reported [36,37]. The formation and isolation of solid complexes between P-cyclodextrin and Cl Acid Red 42, Cl Acid Blue 40 or Erionyl Bordeaux 5BLF (Ciba) have been reported [29]. 

The formation and isolation of solid complexes between cyclodextrins and reactive dyes have been reported, but no dyeing results were presented [29]. Complexes were formed between P-cyclodextrin and Cl Reactive Orange 16, Violet 5, Blue 38 or Blue 114 and between y-cyclodextrin and Cl Reactive Blue 38 or Blue 114. 

Silver perchlorate forms solid complexes with aniline, pyridine, toluene, benzene and many other aromatic hydrocarbons [1], A sample of the benzene complex exploded violently on crushing in a mortar. The ethanol complex also exploded similarly, and unspecified perchlorates dissolved in organic solvents were observed to explode [2], Solutions of the perchlorate in benzene are said to be dangerously explosive [3], but this may be in error for the solid benzene complex. The energy released on decomposition of the benzene complex has been calculated as 3.4 kJ/g, some 75% of that for TNT [4],... 

Air should not be drawn through solutions of the compound in ether, or through its solid complex with dioxane, because such materials have occasionally ignited in air. 

The monohydrate explodes at 109 -110° C during slow heating [ 1 ]. The solid complex exploded when manipulated on a glass sinter with a metal spatula [1]. Preparation on small scale and use of plastic equipment is recommended [2],... 

Treatment of the complex salt with acid liberates the corresponding complex ferri-cyanic acid, an oxidant which is rather endothermic (AH°f (aq) +640.5 kJ/mol, 2.96 kJ/g), and which forms solid complexes with ether, etc. 

Contact with acids liberates the solid complex ferrocyanic acid which is endothermic (AH°f (aq) +534.7 kJ/mol, 2.48 kJ/g), and forms complexes with diethyl ether etc. 

The solid complex is very sensitive to light and explodes violently on heating in an open crucible. A drop of cone, nitric acid added to the dry compound causes explosion. 

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