MS22-P07 Crystal and electronic structure of 3-(2'-tetrahydropyranyloxy)-4-methylthiazole-2(3H)-thione Jozef Kozisek (Institute of Physical Chemistry and Chemical Physics, Slovak University of Technology in Bratislava , Bratislava, Slovakia) Julia Koziskova (Institute of Physical Chemistry and Chemical Physics, Slovak University of Technology in Bratislava , Bratislava, Slovakia) Lukáš Bučinský (Institute of Physical Chemistry and Chemical Physics, Slovak University of Technology in Bratislava , Bratislava, Slovakia) Peter Herich (Institute of Physical Chemistry and Chemical Physics, Slovak University of Technology in Bratislava , Bratislava, Slovakia) Jens Hartung (Fachbereich Chemie, Organische Chemie, Technische Universität Kaiserslautern, Kaiserslautern, Germany) Mike Müller (Fachbereich Chemie, Organische Chemie, Technische Universität Kaiserslautern, Kaiserslautern, Germany)email: jozef.kozisek@stuba.skThe title compound is an O-ester structurally deriving from heterocyclic thiohydroxamic acid 3-hydroxy-4-methylthiazole-2(3H)-thione. When heated in the presence of organic peroxides or azo compounds as chemical initiators, the nitrogen-oxygen bonds in 3-alkoxy-4-methylthiazole-2(3H)-thiones breaks homolytically to yield oxygen-centered radicals in unprecedented specificity. Increasing steric demand at oxygen along the sequence primary, secondary, and tertiary alkyl surprisingly shortens the nitrogen oxygen bond in O-alkyl thiohydroxamates pointing to an unknown stabilizing electronic effect induced by steric demand. This responsivity is particularly significant for thiazole-2(3H)-thione-derived cyclic thiohydroxamic acids. In order to correlate N,O-bond lengths to changes in electron distribution the crystal and electronic structure of 3-(2'-tetrahydropyranyloxy)-4-methylthiazole-2(3H)-thione, C9H13NO2S2, has been determined and analyzed in terms of connectivity and packing patterns. The compound crystallizes in the monoclinic crystal system in the space group P21/n.
Data collection was performed on a Stoe STADIVARI diffractometer with a Dectris Pilatus 300K detector and with an Incoatec IμS Ag microfocus source (Ag-Kα, λ = 0.56083 Å) at 100 K using a nitrogen gas open-flow cooler Cobra from Oxford Cryosystems. Data reduction was processed using X-Area [1]. For numerical absorption corrections a crystal-shape model with 17 faces was employed. Resolution of 0.37 Å, an average redundancy of 14.29 gives Rint of 7.22%. Multipole refinement was performed on F2 using XD suite of programs. The preliminary results shows that both N1 and O1 atoms are negatively charged and that the Laplacian has a small positive value. Comparison of experimental and theoretical results will be discussed.
 
References:

[1] STOE & Cie GmbH (2016). X-Area 1.76, software package for collecting single-crystal data on STOE area-detector diffractometers, for image processing, scaling reflection intensities and for outlier rejection; Darmstadt, Germany.

[2] Hübschle, C. B., Dittrich, B.; J. Appl. Crystallogr. 2011, 44, 238 –240.

Keywords: quantum crystallography, IAM analysis, charge density