Speaker
Description
Pertechnetate (TcO4-–) is among the anions that are considered the most environmentally mobile. This is due to its relatively large size and low negative charge density distributed at the four oxygen atoms [1-4]. The negatively charged anions repel from the negatively charged surface of most minerals. Conversely, they are attracted by positively charged residues of nitrogenous bases like adeninium in acidic environments. The model characteristics for this behavior might be understood by analyses of the corresponding structures in the adeninium compounds. We first synthesized the compond of adeninium pertechnetate (С4H6N5)TcO4 (I) by interaction of 0.1 M aqueous solutions of (С4H6N5)Cl with 0.1 M NaTcO4 followed by slow evaporation of the resulting solution till the single crystals started being formed. Compound (I) is described by the formula (С4H6N5)TcO4, it contains in its composition doubly charged adenine cations, two perrhenate anions and crystallizes as colorless crystals in the monoclinic syngony, Z = 8, pr gr. _____. The parameters of the unit cell are: a = 9.2585(3), b = 9.3131(3), c = 20.7305(5) Å, The system of hydrogen bonds in (I) is represented by classical N-H ∙∙∙ O bonds.
The structure contains 4 crystallographically independent formula units. There is pseudo-translation b/2. The anions associated with pseudotranslation have different orientation, the orientation of the cations is preserved.
The X-ray diffraction experiment was performed at the Center for Collective Use of Physical Methods of Investigation the IPCE RAS on an automatic four-circle diffractometer with a two-dimensional Bruker KAPPA APEX II detector (MoKα radiation, λ = 0.71073 Å).
- E. A. Katayev, G. V. Kolesnikov and J. L. Sessler, Chem Soc Rev, 2009, 38, 1572-1586.
- L. Zhu, C. L. Xiao, X. Dai, J. Li, D. X. Gui, D. P. Sheng, L. H. Chen, R. H. Zhou, Z. F. Chai, T. E. Albrecht-Schmitt and S. Wang, Environ Sci Tech Let, 2017, 4, 316-322.
- P. Yu, S. A. Wang, E. V. Alekseev, W. Depmeier, D. T. Hobbs, T. E. Albrecht-Schmitt, B. L. Phillips and W. H. Casey, Angew Chem Int Ed, 2010, 49, 5975-5977.
- G. V. Kolesnikov, K. E. German, G. Kirakosyan, I. G. Tananaev, Y. A. Ustynyuk, V. N. Khrustalev and E. A. Katayev, Org Biomol Chem, 2011, 9, 7358-7364.
