Para -chloranil

Use of nonaqueously prepared DEAE celluloses as Lewis bases offers potential for formation of metal ion complexes between transition metal ions such as Cu and Ni 2j formation of charge-transfer complexes with electron acceptor compounds such as ortho-and para-chloranils or bromanils and with other Lewis acid compounds such as BI3. 

Complexing of DEAE with BI3 resulted in an increase of BE of the Ni electrons of DEAE from 399 eV to approximately 402 eV. With charge transfer complexes, formed with ortho- or para-chloranils, the BE of Ni electrons shifted to 401.4 eV (Fig. 15) and the Cl2p electrons had BE values of 197 for the Cl ion and 200.4 for the organic chlorine. These complexes were paramagnetic, as illustrated by the EPR spectrum for the DEAE-o-chloranil complex shown in Figure 16. The singlet of g-value of 2.0059, indicates... 

Scheme 52 Pyridobenzimidazole-8,9-diones from para-chloranil 5.

Two of the chlorine atoms (para to each other) in chloranil are very reactive... 

To cite another of the many possible examples, tetrachloro-p-quinone (chloranil) is transformed under similar conditions to give the hexachloro-p-diketone derivative (III). Hydrolysis of this para derivative with caustic soda caused the ring to break with formation of dichlormaleic acid, trichloroethylene, and sodium chloride as follows ... 

USE Fungicide. In manuf of chloranil electrodes for pH measurements. As reagent for pamaquine (Plasmochin) in urine (blue color) Schulemann et ai, Chem. Zentr. 1928, I, 2193. Two of the chlorine atoms in para position are easily subetituted, and compds such as 2,5-dianitino-3,6-dichloro-quinone are much used in the dye industry. Caution May ba irritating to skin, mucous membranes. 

For example, the structure of the radical cation of 1,2-diphenylcyclopropane has been assigned on the basis of the analysis of CIDNP data formed in the act of photoinduced reversible electron transfer from cyclopropane to chloranil. The choice has been made between closed and open structures of the radical cation of 1,2-diphenylcyclopropane (Figure 4). The observed CIDNP effects of 1,2-diphenylcyclopropane (absorption of aromatic ortho-, para-, and Hd, and the emission of Hp) comply only with the open structure. 

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