trans-Dichlorobis[o-phenylenebis(dimethylarsine)]technetium(III), perchlorate and chloride salts

Abstract

Abstract.trans- [TcClz(diars) The six-coordinate Tc complex has trans chloride ligands and four As atoms from two nearly coplanar o-phenylenebis(dimethylarsine) ligands, giving ideal D2h symmetry in each case (C1-salt, site symmetry 1; C102 salt, site symmetry 2). The mean Tc-As distance is 2.512 (2) A (four independent distances, range 0.011 A), whereas those for Tc-C1 are 2.348 (8), 2.288 (7), and 2.329 (1) A. The C10 4 salt is yelloworange, whereas the C1-salt is dark red.

The Present Status of Technetium Chemistry

“…(Table 10). The transchloride ligands of the six-coordinate [TcCl 2 (diars) 2 ] + and the four As atoms of the two nearly coplaner diarsine ligands give ideal D 2h symmetry [179]. The eight-coordinate cation [TcCl 4 (diars) 2 ] + exhibits a D 2d dodecahedral coordination geometry [180].…”

Solid State Study on Rhenium Dimethylphosphinoethane Complexes: X‐ray Crystal Structures of trans‐[ReO2(dmpe)2]PF6·2H2O, trans‐[ReO(OH)(dmpe)2](CF3SO3)2, trans‐[ReN(Cl)(dmpe)2]CF3SO3 and trans‐[ReCl2(dmpe)2]ReO4

“….839 (8) .853(6)' ' .613(9) .794 (7) 80.9(2) 80.57(3) 81.00(7) 81.5(2) --- 82.4(1) (Glavan et al. 1980) (Vanderheyden et al.…”

Use of software to search for higher symmetry: space group C2

“…2.10. COPARS (Pauling et al, 1970) and DASTCA10 (Elder et al, 1980) These two compounds ± trans-[MCl 2 (diars) 2 ]ClO 4 , with M = Co (COPARS) or Tc (DASTCA10) and diars = o-C 6 H 4 [As(CH 3 ) 2 ] 2 ± are isostructural, space group C2. While the two structures conform closely to space group C2am, both sets of authors reported signi®cantly poorer re®nement results in C2am than in C2; our attempts to re-re®ne the structure of DASTCA10 in C2am were also unsatisfactory.…”