Hydrogen chloride bonding

There are several examples of crown ether complexes where yttrium is not bound to the crown ether. [Y(H20)8]C13 (15-crown-5) has a [Y(H20)8]3+ cation (distorted dodecahedron) with the crown ether and chloride hydrogen bonded to the coordinated water molecules.58,225 An aqueous solution containing yttrium triflate and 18-crown-6 produces crystals of [Y(CF3-COO)2(H20)6](CF3COO),(18-crown-6) which have the crown ether hydrogen bonded to the coordinated water molecules.226 The complex [Y(N03)3(H20)3] (dibenzo-24-crown-8) has a nine-coordinate yttrium formed by bonding to three bidentate nitrate groups and three water molecules. The crown ether is hydrogen bonded to the water molecules.227... 

Fig. 4 Side and top views of the minimized structures at the MP2/6-31+G level of a the triazine chloride aryl centroid complex and b the triazine chloride hydrogen-bonding complex. The triazine and the chloride are shown in a scaled ball-and-stick representation...

Figure 8.3 (a) A portion of a urea-water-chloride hydrogen-bonded layer, (b) Layer-type structure of (C2H5)4N" X (NH2)2CO-2H2O, whereX= Cl, Br[2], Symmetry transformation a (I - X, 1 - y, -z)... 

If tetramethylammonium chloride is dissolved in hydrochloric acid, the unstable salt [(CH3)4N] [HClj], can be crystallised out here chlorine is showing weak hydrogen bonding (cf. F H—F which is stable, and Cl - H—Cl which is unstable). 

FIGURE 8 4 Solvation of a chloride ion by hydrogen bonding with water... 

The entropy value of gaseous HCl is a sum of contributions from the various transitions summarized in Table 4. Independent calculations based on the spectroscopic data of H Cl and H Cl separately, show the entropy of HCl at 298 K to be 186.686 and 187.372 J/(mol K) (44.619 and 44.783 cal/(mol K), respectively. The low temperature (rhombic) phase is ferroelectric (6). SoHd hydrogen chloride consists of hydrogen-bonded molecular crystals consisting of zigzag chains having an angle of 93.5° (6). Proton nmr studies at low temperatures have also shown the existence of a dimer (HC1)2 (7). 

Iron(II) chloride tetrahydrate [13478-10-9] FeCl24H20, is obtained by dissolving iron metal ia aqueous HCl and ahowiag the product to crystallize at room temperature. The sohd consists of monomeric trans- octahedra which hydrogen bond extensively with each other. Iron(II) chloride... 

Poly(vinyhdene chloride) also dissolves readily in certain solvent mixtures (82). One component must be a sulfoxide or A/,Al-diaIk5lamide. Effective cosolvents are less polar and have cycHc stmctures. They include aUphatic and aromatic hydrocarbons, ethers, sulfides, and ketones. Acidic or hydrogen-bonding solvents have an opposite effect, rendering the polar aprotic component less effective. Both hydrocarbons and strong hydrogen-bonding solvents are nonsolvents for PVDC. 

It has, however, been possible to find solvents for some polar crystalline polymers such as the nylons, poly(vinyl chloride) and the polycarbonates. This is because of specific interactions between polymer and solvent that may often occur, for instance by hydrogen bonding. 

Isotope labeling by derivative formation with deuterated reagents is useful for the preparation of analogs such as dg-acetonides, da-acetates, da-methyl ethers, dg-methyl esters, etc. The required reagents are either commercially available or can be easily prepared. (The preparation of da-methyl iodide is described in section IX-F. Various procedures are reported in the literature for the preparation of dg-acetone, da-diazometh-ane57.i63.i73 and da-acetyl chloride. ) These reactions can be carried out under the usual conditions and they need no further discussion. A convenient procedure has been reported for the da-methylation of sterically hindered or hydrogen bonded phenolic hydroxyl functions by using da-methyl iodide and sodium hydroxide in dimethyl sulfoxide solution. This procedure should be equally applicable to the preparation of estradiol da-methyl ether derivatives. 

During electrochemical fluorination retention of important functional groups or atoms in molecules is essential. Acyl fluorides and chlorides, but not carboxylic acids and anhydrides (which decarboxylate), survive perfluorination to the perfluorinated acid fluorides, albeit with some cyclization in longer chain (>C4) species [73]. Electrochemical fluorination of acetyl fluoride produces perfluoro-acetyl fluoride in 36-45% yields [85]. Electrochemical fluorination of octanoyl chloride results in perfluorinated cyclic ethers as well as perfluorinated octanoyl fluonde. Cyclization decreases as initial substrate concentration increases and has been linked to hydrogen-bonded onium polycations [73]. Cyclization is a common phenomenon involving longer (>C4) and branched chains. a-Alkyl-substituted carboxylic acid chlorides, fluorides, and methyl esters produce both the perfluorinated cyclic five- and six-membered ring ethers as well as the perfluorinated acid... 

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