U. Abram et al., SYNTHESES AND STRUCTURES OF (ET(4)N)(2)[R E(CO)(3)(NCS)(3)] AND (ET(4)N)[RE(CO)(2)BR4], Zeitschrift fur anorganische und allgemeine Chemie, 622(5), 1996, pp. 813-818
Citations number
18
Categorie Soggetti
Chemistry Inorganic & Nuclear
Journal title
Zeitschrift fur anorganische und allgemeine Chemie
Rhenium(I) and rhenium(III) carbonyl complexes can easily be prepared
by ligand exchange reactions starting from (Et(4)N)(2)[Re(CO)(3)Br-3].
Using nonoxidizing reagents the facial Re-1(CO)3 unit remains and onl
y the bromo ligands are exchanged. Following this procedure, (Et(4)N)(
2)[Re(CO)(3)(NCS)(3)] can be obtained in high yield and purity using t
rimethylsilylisothiocyanate. The compound crystallizes in the monoclin
ic space group P2(1)/n, a = 18.442(5), b = 17.724(3), c = 18.668(5) An
gstrom, beta = 92.54(1)degrees, Z = 8. The NCS- ligands are coordinate
d via nitrogen. The reaction of [Re(CO)(3)Br-3](2-) with Br-2 yields t
he rhenium(III) anion [Re(CO)(2)Br-4](-). The tetraethylammonium salt
of this complex crystallizes in the noncentrosymmetric, orthorhombic s
pace group Cmc2(1), a = 8.311(1), b = 25.480(6), c = 8.624(1) Angstrom
, Z = 4. The carbonyl ligands are positioned in a cis arrangement. The
ir strong trans influence causes a lengthening of the Re-Br bond dista
nces by at least 0.05 Angstrom.