The electron acceptor activity of the metal atom in Th(IV) oxinate

Abstract

The slow reaction of ThOx 4(HOx = oxine) with chloroacetic acid HR (HR c , HR b and HR a refer to trichloro-, dichloro-, and monochloroacetic acid respectively) in benzene for 24 hr led to the formation of acid adducts and mixed ligand complexes depending on the molar ratio of reactants. With the acid to Th(IV) complex molar ratios of 1:1, 2:1, 3:1, 4:1 and 10:1 the isolated compounds for HR c were formulated as ThOx 3R c (I), [ThOx 3R c ] 2 HR c (II), ThOx 3R c · HR c (III), [ThOx 3R c · 2HR c ] 2HR c (IV), and compound(IV) respectively, for HR b these were formulated as ThOx 3R b (V), ThOx 2(R b ) 2 · HOx(VI ThOx 2(R b ) 2(VII), ThOx(R b ) 3 · HOx(VIII) and [ThOx(R b ) 3 · HOx · HR b ]HR b (IX) respectively, and for HR b the compounds were formulated as ThOx 3R a (X), ThOx 2(R a ) 2(XI), [ThOx 2(R a ) 2] 2HR a (XII), ThOx(R a ) 3(XIII), and compound (XIII) respectively. Unchanged compounds were obtained on boiling compounds I–XIII in benzene except for compound (IX) which gave compound (VII). Similar reaction with chloroform led to changing compounds (II), (IV), (VI), (IX), and (XII) into (III), ThOx 2(R c ) 2 · HR c (XIV), (VII), ThOx(R b ) 3(XV), and (XI) respectively, while the other compounds were stable. On refluxing the Th(IV) oxinate with the chloroacetic acids in benzene, the isolated compounds have the formulations of those obtained from the slow reaction although not necessarily from same molar ratio of reactants with the exception of the 10:1 molar ratio reaction with HR c which gave ThOx(R c ) 3 · HOx · HR c (XVI). The reaction of compounds (VIII), (IX), (XIV) and (XVI) with methyl alcohol led to the decoordination of the acid molecules in the case of the last three compounds while for compound(XIV) the methyl alcohol solvate ThOx(R c ) 2(OCH 3) · CH 3OH(XVII) was formed. A similar reaction of the four compounds in the presence of oxine (1:1) afforded compound (I) from either compound (XIV) or (XVI) and compound (V) from either compound (VIII) or (IX). The formation of these compounds are discussed in relation to the electron acceptor activity of the metal atom. These formulations are in accordance with analytical and spectral evidence.