SYNTHESIS AND CRYSTAL-STRUCTURE OF A NEW-TYPE OF IONIC TECHNETIUM(V) DIOXO PHOSPHINE COMPLEXES, [TC(O)2(PR3)(3)](- REACTIONS WITH PYRIDINE AND CRYSTAL-STRUCTURES OF TRANS,CIS,CIS-[TC(O)(2)(PR3)(2)(PY)(2)](+) COMPOUNDS() )

New ionic technetium complexes of the type [TcO2(PR3)(3)](+) have been synthesized from the reaction of [TcO4](-) with the phosphine in meth anol. The crystal structures of two crystallographic forms of [TcO2(PE t3)(3)](BPh4) were determined. The first form is monoclinic, space gro up P2(1)/n with a = 14.353(3) Angstrom, b = 11.731(2) Angstrom, c = 26 .478(6) Angstrom, beta = 101.22(1)degrees, and Z = 4. The second form is also monoclinic, space group P2(1)/c with a = 10.043(3) Angstrom, b = 21.122(4), c = 20.994(5) Angstrom, beta = 97.43(2)degrees, and Z = 4. [TcO2(PPr3)(3)](BPh4) belongs to the monoclinic C2/c space group wi th a = 34.097(7) Angstrom, b = 16.944(4) Angstrom, c = 19.033(4) Angst rom, beta = 102.99(1)degrees, and Z = 8. The geometry around the Tc at om is a trigonal bipyramid with the two oxo ligands in the trigonal pl ane. The Tc-O bond distances are between 1.707(4) and 1.726(3) Angstro m, while the Tc-P bonds vary from 2.507(2) to 2.528(2) Angstrom for th e axial ligands and between 2.395(1) and 2.403(1) Angstrom for the equ atorial bond. The O-Tc-O angles are in the range 141.5(2)-143.4(2)degr ees. The reaction of these complexes with pyridine produced trans, cis , cis-[Tc(O)(2)(PR3)(2)(py)(2)](+) (PY = pyridine). [Tc(O)(2)(PMe3)(2) (py)(2)](BPh4) is monoclinic, space group P2(1)/c with a = 30.346(8) A ngstrom, b = 12.865(4) Angstrom, c = 21.464(9) Angstrom, beta = 110.35 (2)degrees, and Z = 8, while [Tc(O)(2)(PEt3)(2)(py)(2)](BPh4) is monoc linic, space group P2(1)/c with a = 10.594(6) Angstrom, b = 19.921(7) Angstrom, c = 21.306(10) Angstrom, beta = 95.31(5)degrees, and Z = 4. The geometry around the Tc atom is a distorted octahedron with the oxo ligands located in trans positions to each other, while the phosphine and the pyridine ligands are cis to each other.