ACIDITY OF DIBASIC CARBON ACIDS .5. THE 2ND ACIDITY CONSTANT OF 9,10-DIHYDRODIBENZ[ALPHA,H]ANTHRACENE IN TETRAHYDROFURAN-GEOMETRY, CHARGE-DISTRIBUTION OF DIANION, STRUCTURE OF DIMETALLIC SALTS
M. Nir et al., ACIDITY OF DIBASIC CARBON ACIDS .5. THE 2ND ACIDITY CONSTANT OF 9,10-DIHYDRODIBENZ[ALPHA,H]ANTHRACENE IN TETRAHYDROFURAN-GEOMETRY, CHARGE-DISTRIBUTION OF DIANION, STRUCTURE OF DIMETALLIC SALTS, Perkin transactions. 2, (2), 1997, pp. 329-332
The second equilibrium ion pair acidity constant (pK(2)) of 9,10-dihyd
rodibenz[a,h]anthracene (DBDHA, 1H(2)) with counter ions sodium (pK(2)
28.5) and potassium (pK(2) 30.4) has been determined in tetrahydrofur
an (THF) at 298 K, This value is considerably lower than for other 9,1
0-dihydroanthracene derivatives. Disodium,dipotassium and dirubidium s
alts of DBDHA, i.e, 1(2-), exist as contact ion triplets in THF at 298
K, although the dilithium salt behaves as a solvent-separated ion tri
plet under the same conditions, In the dianion of DBDHA (1(2-)) the ne
gative charge is displaced from the deprotonated carbon atoms towards
the outer benzene rings.