Reactivity of 2-(2-hydroxyphenyl)benzothiazoline with the oxotetrahalometalate(V) complexes [MOX4]- (M = technetium, rhenium; X = Cl, Br). Synthesis and characterization of new oxo-M(V) complexes containing 2-(2-hydroxyphenyl)benzothiazole. Crystal structure of tetraphenylarsonium oxotrichloro[2-(2-hydroxyphenyl)benzothiazolato]technetate(V)

2-(2-Hydroxyphenyl)benzothiazoline (hbtH) is converted into its oxidized form, 2-(2-hydroxyphenyl)benzothiazole (hbt), by interaction with the five-coordinate tetrahalooxometalate(V) complexes [MOX4]- (M = Te, Re; X = CI, Br). The reaction proceeds very rapidly at room temperature, and only a small amount of metal complex is necessary to obtain conversion of a large excess of hbtH to hbt. When this conversion is conducted in acetone, the formation of isopropyl alcohol is detected within a few minutes after mixing the reagents. When M = Re, an intermediate in the reaction sequence can be isolated; this intermediate contains one ligand comprised of the hbt product and one ligand comprised of the Schiff base tautomeric form of the hbtH starting material [i.e., N-(2-mercaptophenyl)salicylideneamine, S-phsalH2] and is formulated as the six-coordinate Re(V) complex [ReO(S-phsal)(hbt)]. A general scheme accounting for these and other results is given. The hbt ligand also reacts directly with [MOX4]- to yield [MOX3(hbt)]-- anions and [MOX(hbt)2] complexes, which have been characterized by elemental analyses and IR, 1 NMR, and mass spectral analyses. The [TcOCl3(hbt)]- anion is characterized by single-crystal X-ray structural analysis refined to a conventional R factor of 0.045 for 3041 observed reflections with I > 2σ(I). Red-orange crystals of the tetraphenylarsonium salt crystallize in the orthorhombic space group P2121, with a = 12.104 (2) Å, b = 13.772 (3) Å, c = 20.539 (4) Å, and V = 3424 (1) Å3 with Z = 4. The Tc(V) center is in a distorted-octahedral configuration with the three chlorine atoms and the neutral nitrogen atom of the hbt ligand in the plane normal to the Tc═O linkage and the anionic phenolate oxygen atom of the hbt ligand situated trans to the Tc═O linkage. © 1988, American Chemical Society. All rights reserved.