THE SYNTHESIS, CHARACTERIZATION AND SUBSTITUTION-REACTIONS OF THE MIXED-LIGAND TECHNETIUM(I) NITROSYL COMPLEX TRANS-TRANS-[(NO)(NCCH3)CL-2(PPH(3))(2)TC]

The technetium-nitrosyl complex n-Bu(4)N[Tc(NO)Cl-4] reacts with exces s triphenylphosphine in refluxing acetonitrile to give the Tc(I) mixed ligand complex [Tc(NO)Cl-2(PPh(3))(2)NCCH3] in good yield. The IR spe ctrum of this complex displays an absorption at 1690 cm(-1) which is a ssociated with upsilon(NO). The FAB(+) mass spectrum shows the fragmen t of 723 m/z which corresponds to [Tc(NO)Cl-2(PPh(3))(2)](+) which is generated from the loss of the acetonitrile ligand. The H-1 NMR spectr um of this species displays equivalent trans-triphenylphosphine ligand s; however because of the lability of the acetonitrile ligand, two sig nals are observed from the coordinated and dissociated acetonitrile pr otons. The analogous reaction in methanol gives the methanol adduct [T c(NO)Cl-2(PPh(3))(2)HOCH3]. When pyridine is employed as solvent, the tris-pyridine complex [Tc(NO)Cl-2(py)3] is isolated as the major produ ct, with no phosphine coordination. The LR spectrum of this complex sh ows an absorption at 1688 cm(-1) which is associated with upsilon(NO). The FAB(+) mass spectrum shows the fragment of 436 m/z which correspo nds to the parent ion [Tc(NO)Cl-2(py)(3)](+). This diamagnetic Tc(I) c omplex displays a well resolved, narrow-lined H-1 NMR spectrum. Crysta l data for [Tc(NO)Cl-2(py)(3)]. 2CH(3)CN: monoclinic space group C2/c, (No. 15), a=19.182(1), b=10.8725(8), c=11.9371(8) Angstrom, beta=116. 580(7)degrees, V=2226.5(6) Angstrom(3), with D-calc=1.543 g cm(-3) to give Z=4. Structure solution based on 2689 reflections converged at R= 0.025, R(w)=0.030, GOF=1.41. The reaction chemistry of the acetonitril e adduct [Tc(NO)Cl-2(PPh(3))(2)NCCH3] with pyridine, 3,5-lutidine, bip yridine, phenanthroline and terpyridine is also presented.