(Diamine)tetracarboxylatoplatinum(IV) complexes, A2Pt(OOCR)4 (A2=trans-(±)-1,2-diaminocyclohexane (dach), 2,2-dimethyl-1,3-propanediamine (dmpda), ethylenediamine (en), 2 NH3, 2 cyclopropylamine (cpa); R=CH3, C2H5), have been facilely synthesized by reacting (diamine)tetrahydroxoplatinum(IV) with carboxylic anhydrides in dichloromethane, and their structural properties were examined by X-ray analysis and 1H NMR spectroscopy. The reactant (dach)Pt(OH)4 crystallizes in the triclinic space group P1̄ (No. 2) with two molecules in an asymmetric unit and the local geometry around the platinum(IV) atom is a regular octahedron, but the carboxylated product (dach)Pt(O2CCH3)4 crystallizes in monoclinic space group P21/c (No. 14) and the platinum(IV) atom is in a distorted octahedral environment. The most interesting structural aspect of the title complexes is that the equatorial Pt(IV)-carboxylate bonds are slightly longer than the axial ones, probably due to the difference in trans influence of the nitrogen and oxygen donating atoms. The 1H NMR spectra also show that the axial and equatorial acetate groups are not equivalent.
Bibliographical noteFunding Information:
This research was financially supported by the Ministry of Science and Technology in Korea.
- Carboxylato complexes
- Crystal structures
- Diamine complexes
- Platinum complexes