I. INTRODUCTION
cis-[diiodo(1R,2R)-1,2-diaminocyclohexane (DACH)-κ N,κ N′] platinum(II) [Pt(C6H14N2)I2] is a new platinum-based anticancer complex. The search for novel platinum-based anticancer complexes remains an expanding area of the contemporary pharmaceutical industry. The driving force for investigations of this group of active anticancer therapeutics is the discovery of more active and less toxic analogues of the chemotherapy complexes used in today’s clinical practice such as cisplatin, carboplatin, oxaliplatin, etc. (Ho et al., Reference Ho, Au-Yeung and To2003; Galanski et al., Reference Galanski, Arion, Jakupec and Keppler2003; Abu-Surrah and Kettunen, Reference Abu-Surrah and Kettunen2006). Some of the novel structures are based on the platinum (1R,2R)-1,2-DACH carrier ligand and various leaving groups bound to the central Pt metal atom.
II. SAMPLE PREPARATION
The title compound (Figure 1) was prepared from a solution of K2[PtCl4] (0.029 mol, 12.0 g) in water (88 ml) mixed with the solution of KI (0.202 mol, 33.6 g) in water (29 ml). The mixture was stirred for 30 min and then a solution of DACH tartrate (0.032 mol, 8.51 g) in water (20 ml) was added. The pH value of the reaction mixture was adjusted with potassium hydroxide. The reaction mixture was stirred in the absence of light at 45 °C for 8 h. Subsequently, the product was filtered off from the suspension by filtration through sintered glass and dried in a vacuum drier. The resulting yellow powder, crude cis-[Pt(DACH)I2], was obtained yielding 98.5%.
POWDER DIFFRACTION DATA
The diffraction pattern for the title compound was collected at room temperature with an X’Pert PRO θ-θ powder diffractometer with parafocusing Bragg-Brentano geometry using Cu K α radiation (λ=1.5418 Å, generator setting: 40 kV, 30 mA). An ultrafast X’Celerator detector was employed to collect XRD data over the angular range from 7° to 70° 2θ with a step size of 0.017° 2θ and a counting time of 81.28 s/step. The experimental powder diffraction pattern is depicted in Figure 2 indicating that the powder specimen was preferred oriented. Data evaluation was performed using the software package HIGHSCORE PLUS V 2.2e PANalytical, Almelo, The Netherlands. The data collected are consistent with the monoclinic cell parameters [a=14.048(4) Å, b=7.588(3) Å, c=11.502(4) Å, β=98.446(5)°, space group C2 with cell volume=1212.80 Å3, and Z=4]. These parameters were derived using DICVOL04 (Boultif and Louër, Reference Boultif and Louër2004) with the results all being within the errors indicated. The indexing results are listed in Table I. The following figures of merits were achieved: F 20=36.4 (0.0087, 63) (Smith and Snyder, Reference Smith and Snyder1979) and M 20=19.7.
ACKNOWLEDGMENTS
The authors would like to thank to Petr Kačer and Jitka Housková from the Institute of Chemical Technology, Prague, for the sample preparation. This work was supported by Grant No. MSM 6046137301 and research programme 2B08021 of the Ministry of Education, Youth and Sports of the Czech Republic and by Grant No. MPO 2A-2TP1/049 from the Ministry of Industry and Trade of the Czech Republic.
Figure 1. Structural formula of cis-DACH Pt iodide.
Figure 2. (Color online) X-ray powder diffraction pattern of cis-DACH Pt iodide using Cu K α radiation (λ=1.5418 Å).
TABLE I. Indexed X-ray powder diffraction data for cis-DACH Pt iodide. Only the peaks with I rel of 1 or greater are presented [a=14.048(4) Å, b=7.588(3) Å, c=11.502(4) Å, β=98.446(5)°, V=1212.80 Å3, Z=4, and space group C2]. All lines were indexed and are consistent with the C2 space group.
