1,3,5-Triamino-1,3,5-trideoxy-cis-inositol, a ligand with a remarkable versatility for metal ions: Part XIII - Complex formation with rhenium(I) and rhenium(VII)

The two neutral complexes [Re(CO)₃(H_₁taci)] (1) and [ReO₃(H_₁taci)] (2) (taci = 1.3,5-triamino-1,3.5-trideoxy- cis-mositol) were synthesized from the conventional Re^I and Re ^VIII precursors (Et₄N)₂[ReBr ₃(CO)₃] and [ReO₃(OSnMe₃)]. The crystal structures of 1 and 2, which were determined by single crystal X-ray analysis, are virtually isomorphous. Both compounds crystallize in the orthorhombic space group Pnma, Z = 4; 1: a = 14.806(3), b = 8,466(2), c = 9.781(2) Å, 2: a = 13.050(2), b = 8.732(1), c = 9.061(1) Å. In both complexes, the monodeprotonated H_¹ ,taci ligand is bonded to the Re center in an N,O,N-coordination mode. The resulting molecular C_s symmetry is retained in the crystal structure and confirmed by IR spectroscopy of solid-state samples. The observed binding mode of the ligand is discussed in terms of steric and electronic effects.