Synthesis and characterization of a technetium nitrido dimer

In 1993, Baldas et al. [1] reported the synthesis of the technetium(VI) nit ridodi (eta -oxo) dimer (AsPh4)(2)[{TcNCl2}(2)(mu -O)(2)], which was synthe sized from methanesulfonic acid and Cs-2[TcNCl5] in water with heating. We report hers, the facile synthesis and characterization of the tetrabutylamm onium analog, (Bu4N)(2)[{TcNCl2}(2)(mu -O)(2)] (1), which is synthesized fr om (Bu4N)[TcNCl4] and water in acetone at room temperature. This may have i mportant ramifications for technetium based radiopharmaceutical development , since [(TcNCl4)-Tc-99](-) is frequently employed at the tracer level as a technetium nitrido synthon, and technetium nitrido chemistry continues to be a rapidly developing area in radiopharmaceutical research [1]. The infrared spectrum of 1 displays a pronounced absorption at 1062 cm(-1), attributed to the Tc=N bond. The FAB(-) mass spectrum displays the parent ion of 642 m/z which corresponds to {(Bu4N)[{TcNCl2}(2)(mu -O)(2)]}(-) The X-ray crystal structure of 1 is similar to the previously reported tetraphe nylarsonium analog [2]. The technetium nitrogen triple bond lengths are 1.6 01(7) and 1.597(7) Angstrom. The X-ray structure solution for C32H72C4N2O4T c of molecular weight 886.72 g mol(-1): Monoclinic space group P2(1)/n, al 15.2894(12), b = 16.4321(12), c = 17.9311(14) Angstrom, beta = 105.5100(10) degrees, volume = 4340.9(6) Angstrom (3). Solution based on 6212 independen t reflections to give a final R value of 0.0701 and GOF = 1.124. (C) 2001 E lsevier Science B.V. All rights reserved.