Hydrogen derivative crystal

All ten of the parent phenanthrolines are solids (see Table I). Most of the crystal structure work so far reported has been concerned with 1,10-phenanthroline and its derivatives. Crystal structure data and X-ray powder work on 1,10-phenanthroline hydrate26-28 confirm, as expected, that it exists as the monomer (12) with hydrogen bonding between the nitrogen atoms and the hydrogens of a water molecule.26 Crystal data on 2,9-dimethyl-1,10-phenanthroline have also been described.29... 

A chiral bicyclic diol and its derivatives crystallize in a series of hydrogen-bonded species surrounding parallel channels in which guest molecules can be trapped by a cross section as large as 35 An example for a... 

Figure 5.27 The X-ray crystallographically derived crystal packing of 5.35, highlighting the hydrogen bonding network along the fibre axis.

I lagler A T, E Huler and S Lifson 1977. Energy Functions for Peptides and Proteins. I. Derivation of a Consistent Force Field Including the Hydrogen Bond from Amide Crystals. Journal of the American Chemical Society 96 5319-5327. 

When dextrose is heated with methanol containing a small amount of anhydrous hydrogen chloride, a-methyl-D-glucoside is obtained in good yield and can be isolated by crystallization. Similar reactions occur with higher alcohols, but the reaction products are more difficult to isolate by crystallization. Dextrose reacts with acid anhydrides in the presence of basic catalysts, yielding esters. Complete reaction gives the pentaacylated derivative. 

The ease of oxidation varies considerably with the nature and number of ring substituents thus, although simple alkyl derivatives of pyrazine, quinoxaline and phenazine are easily oxidized by peracetic acid generated in situ from hydrogen peroxide and acetic acid, some difficulties are encountered. With unsymmetrical substrates there is inevitably the selectivity problem. Thus, methylpyrazine on oxidation with peracetic acid yields mixtures of the 1-and 4-oxides (42) and (43) (59YZ1275). In favourable circumstances, such product mixtures may be separated by fractional crystallization. Simple alkyl derivatives of quinoxalines are... 

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