Phenylenes hydrogenation

The reaction between the cyclic phosphorochloridate (109) and a strictly equimolar amount of water yields o-phenylene hydrogen phosphate (110) in the presence of excess water, both (109) and (110) afford the acyclic pho.sphate (112). On the other hand, the cyclic esters and amide (111) with one mole of water each yield the corresponding (113)... 

Dissolve about o i g. of />-phenylene diamine in about 10 ml. of water. Place 5 ml. of milk in each of two test-tubes A and B. Boil the milk in B thoroughly for 2 minutes and then cool. In each test-tube place 5 drops of the phenylenc diamine solution and then add i drop of 20 vol. hydrogen peroxide solution, and mix. A green coloration is produced in A, and then very rapidly changes to a slate-blue. No coloration is produced in B. This test therefore readily differentiates fresh from boiled milk. 

MDA reacts with acid anhydrides to form amides. In the reaction with maleic anhydride both of the amino hydrogens are replaced to form the imide, A[,Ar-(methylenedi-/)-phenylene) dimaleimide [1367-54-5]... 

Hydrogenation of 5,10-diazabenzo[6]biphenylene with Raney nickel in hot ethanol gave 2-phenylquinoxaline in 78% yield (9). Similar hssion of the four-membered ring occurs with biphenylene itself and with substituted bi-phenylenes (5). 

Peroxyacetic acid, >43% and with >6% hydrogen peroxide m-Phenylene diaminediperchlorate (dry)... 

Sediment Trap hydrogen sulfide in sodium hydroxide sulfide reacts with AW-dimethyl-p-phenylene-diamine to from methylene blue. Colorimetry 0.01 pmol/gram NR Allen et al. 1994... 

Figure 32 Structure of compound 194. The hydrogen atom at the 2-position of the mefa-phenylene ring is shown other hydrogen atoms are omitted for clarity. 

Remarkably enough, dialkoxyterephthalic acids, both in 2D and 3D, form linear hydrogen bonded strands which are reminiscent of the rigid rods formed from alkyl substituted poly-para-phenylenes. 

EL pyridine-phenylene copolymers 564 [666] and 565 [667] have been synthesized and studied by Bryce and coworkers. Although a rather low el(<0.1%) was reported for the devices, an interesting phenomenon was found for polymers 565. When the PLED (ITO/PEDOT/565/Ca/Al) was fabricated using acidic solutions, a strong red shift in the EL band compared to that obtained with the neutral solution (from 510 to 575 nm) was observed. The authors explained this concept by planarization of the protonated polymer chain as a result of intramolecular hydrogen bonding N H- O. Variation of pyridine linkage in copolymers 565, 566, and 567 affects the PL and EL emissions (AEL = 444, 432,... 

The solubility and thermal stability of polymers are usually improved and the surface energy is decreased by substituting fluorine atoms for the hydrogen atoms in the isopropylidene units connecting phenylene units in the main chain. 

Furthermore, C-H - - O hydrogen bonds are formed between some of the polyether oxygen atoms and the a-bipyridinium protons. A second type of hydrogen bonding interaction, C-H- -77, is observed between the 1,4-dioxybenzene protons and thep-phenylene spacers. In most systems it is very difficult to measure their individual strength and importance in the assembly process. However, it is usually assumed that rr-stacking between complementary aromatic species is the main supramolecular interaction in these systems. 

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