The 1,1’-dimethylvanadocene dichloride ((C5H4CH3)2VCl2) reacts in aqueous solution with various carboxylic acids giving two different types of complexes. The 1,1’-dimethylvanadocene complexes of monocarboxylic acids (C5H4CH3)2V(OOCR)2 (R=H,CCl3, CF3, C6H5) contain two monodentate carboxylic ligands, whereas oxalic and malonic acids act as chelate compounds of the formula (C5H4CH3)2V(OOC-A-COO) (A=−, CH2). The structure of the (C5H4CH3)2 V(OOCCF3)2 complex was determined by single crystal X-ray diffraction analysis. The isotropic and anisotropic EPR spectra of all the complexes prepared were recorded. The obtained EPR parameter values were found to be in agreement with proposed structures.
 P. Köpf-Maier: “Antitumor activity of titanocene dichloride in xenografted human renal-cell carcinoma”, Anticancer Res., Vol. 19, (1999), pp. 493–504.
 K. Mross, P. Robben-Bathe, L. Edler, J. Baumgart, W. E. Berdel, H. Fiebig and C. Unger: “Phase I clinical trial of a day −1, −3, −5 every 3 weeks schedule with titanocene dichloride (MKT 5) in patients with advanced cancer: A study of the phase I study group of the Association for Medical Oncology (AIO) of the German Cancer Society”, Onkologie, Vol. 23, (2000), pp. 576–579. http://dx.doi.org/10.1159/000055009
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
SYNAT - “Interdisciplinary System for Interactive Scientific and Scientific-Technical Information”.