SYNTHESIS, SPECTROSCOPIC AND ELECTROCHEMICAL STUDIES OF IODO COMPLEXES OF OSMIUM(II), (III) AND (IV) WITH PHOSPHORUS AND ARSENIC DONOR LIGANDS

摘要

The syntheses of a variety of iodo complexes of osmium, including trans-[Os(L-L)(2)I-2](L-L=Ph(2)PCH(2)CH(2)PPh(2), o-C6H4(PPh(2))(2), Ph(2)AsCH(2)CH(2)AsPh(2) or o-C6H4(AsMe(2))(2)), the corresponding trans-[Os(L-L)(2)I-2]BF4, trans-[Os(o-C6H4(AsMe(2))(2))(2)I-2][ClO4](2), trans-[OSL(2)I(4)] (L=PPh(3) or ASPh(3)), trans-[OsL(4)'I-2] (L'=Me(3)P, Me(3)As, Ph(3)Sb) and trans-[OsL(4)'I-2]BF4 are described. The complexes have been characterised by analysis, UV-Vis spectroscopy and cyclic voltammetry, and the results compared with analogues containing lighter halogens. The X-ray structure of trans-[Os(Me(3)As)(4)I-2]I-3, has been determined: orthorhombic, space group Ibam, a=10.290(3), b=13.984(2), c=21.101(3) Angstrom, Z=4 and R=0.032. The cation has Os-I=2.6544(7) and Os-As=2.5013(9) Angstrom. The OsAs4 unit shows deviations from planarity which are presumably due to steric interactions. Osmium L(III),-edge EXAFS data are reported for trans-[Os(o-C6H4(AsMe(2))(2))(2)I-2](+/2+). [References: 28]