Complexes of technetium(III) with sterically hindered arenethiolates and their interactions with small .pi.-accepting molecules

Dinitrogen Cleavage by Three-Coordinate Molybdenum(III) Complexes: Mechanistic and Structural Data1

“…NMR ( vide supra ) and EXAFS ( vide infra ) data for Mo[N(R)Ar] 3 are consistent with an average 3-fold symmetric structure for the molecule in solution, as observed in the solid state. We have no evidence for a “two-up, one-down” structure as has been observed for trigonal bipyramidal tris(arylthiolate)ML 2 complexes (M = Tc, Re; L = e.g., acetonitrile) . Edge-to-face aryl interactions could contribute to the apparent preference for the observed “three-up” structure: metrical parameters for the lowest energy gas-phase structure of the benzene trimer are strikingly similar to those for three aromatic rings oriented as in Mo[N(R)Ar] 3 .…”

Synthesis and characterization of technetium(III) complexes containing 2,2'-bipyridine and 1,10-phenanthroline. X-ray crystal structures of cis(Cl),trans(P)-[TcCl2(P(CH3)2C6H5)2(bpy)]B(C6H5)4, cis(Cl),trans(P)-[TcCl2(P(CH3)2C6H5)2(phen)]B(C6H5)4, and cis(Cl),trans(P)-[TcCl2(P(CH3CH2)(C6H5)2)2(bpy)]SO3CF3

“…These facts together most likely account for the Tc-P(l) distances being slightly shorter (0.021-0.026 Á) than the Tc-P(2) distances in both cases (see Table IV). For the PEtPh2 complex, the phenyl ring C(19)-C (24) of P(l) is in closest proximity to the bpy ligand and there are no atoms eclipsing the chlorine atoms (see Figure 5c); as a result, the Tc-P distances are more similar (0.009 Á difference) with Tc-P(l) being the shorter. Although the P(l)-Tc distance is 0.009 (3) A shorter than the P(2)-Tc distance, the P(l) phosphine ligand is canted away from the bpy moiety more than is the P(2) phosphine ligand, as is evidenced by the average N(l,2)-Tc-P angles of 93.9 (2)°f or P(l) and 89.4 (2)°f or P(2) (difference = 4.5 (3)°).…”

“…-314 ( 5) 3313 (4) 1830 ( 8) 32 (3) C( 12) 1268 ( 9) 1335 ( 7) 5030 ( 11) 63 ( 6) N(2) 464 ( 5) 2582 (4) 358 ( 7) 23 (3) C( 13) -296 (6) 2052 ( 5) 4084 ( 8) 24(3) co)…”

Open-Shell Organometallics as a Bridge between Werner-Type and Low-Valent Organometallic Complexes. The Effect of the Spin State on the Stability, Reactivity, and Structure

“…Technetium(III) compounds with sterically hindered arylthiolato ligands, Tc(SR) 3 L 2 (L = CO, isocyanide) or with the bulky “umbrella” ligand tris( o -thiophenyl)phosphine), [P( o -C 6 H 4 S) 3 ]Tc(CNR‘) are trigonal-bipyramidal, diamagnetic compounds ( CXXIX ). − The π-donation from the equatorial thiolato ligands can provide four additional electrons, making these molecules effectively saturated. The [P( o -C 6 H 4 S) 3 ]Tc(CNR‘) complexes can add a second isocyanide ligand to afford a 16-electron adduct, which is on the other paramagnetic …”