SOLVENT-INDUCED REACTION OF RHODIUM(III)HALIDE WITH N-HETEROCYCLIC LIGANDS - CRYSTAL-STRUCTURE OF NS-DICHLOROTETRAKIS(N-METHYLIMIDAZOLE)RHODIUM(III) CHLORIDE DIHYDRATE
Zd. Matovic et al., SOLVENT-INDUCED REACTION OF RHODIUM(III)HALIDE WITH N-HETEROCYCLIC LIGANDS - CRYSTAL-STRUCTURE OF NS-DICHLOROTETRAKIS(N-METHYLIMIDAZOLE)RHODIUM(III) CHLORIDE DIHYDRATE, Inorganica Chimica Acta, 278(2), 1998, pp. 209-216
The synthesis of complexes of the type trans-[RhL4X2](+) {L = N-alkyli
midazoles (N-RIm) [R = methyl (Me), ethyl (Et), n-propyl (Pr-n) n-buty
l (Bu-n)], 4(6)-hydroxypyrimidine (4(6)-hydPm); X = Cl- or Br-} is ach
ieved by the general catalytic method involving the use of ethanol. Th
e formation of complexes with L = N-MeIm was reexamined and a new proc
edure has been established. The distribution of the trans-[RhL4X2](+)
and [RhL5X](2+) ions as reaction products strongly depends on the natu
re of the solvent and the structure of the ligand. We proposed that th
e initial product trans-[RhL4X(sol)](2+) produced by catalytic action
of ethanol, undergoes nucleophilic substitution reactions either by ha
logenide anions X- or by ligand molecules L, thus giving rise to the f
ormation of trans-[RhL4X2](+) or [RhL5X](2+) complexes. The direction
of the nucleophilic substitution is determined by the concentration of
ethanol, the L ligand and the X- halogen. IR, Raman, electronic absor
ption and H-1 NMR spectra were used to characterize the complexes. The
prepared complexes show significant antifungal activity. The crystall
ographic structure of trans-[Rh(N-MeIm)(4)Cl-2] Cl . 2H(2)O has been d
etermined. The octahedron is slightly distorted since it has, in a squ
are plane, four nitrogen ligands and two Cl atoms at the two apical si
tes. The octahedral bond angles are very close to the ideal values and
are in the range of 88.1(1)-89.6(1)degrees. The Ph atom is located on
the two-fold rotation axis which relates two pairs of N-methylimidazo
le molecules and Cl atoms. (C) 1998 Elsevier Science S.A. All rights r
eserved.