Tris[2,2,6,6-tetra-methyl-8-(tri-methyl-sil-yl)benzo[1,2- d;4,5- d']bis-(1,3-di-thiol)-4-yl]methanol diethyl ether monosolvate

Acta Crystallogr E Crystallogr Commun. 2018 Mar 23;74(Pt 4):539-542. doi: 10.1107/S2056989018004516. eCollection 2018 Apr 1.

Abstract

The title compound, a tri-aryl-methanol, C46H64OS12Si31, was synthesized via li-thia-tion of tris-2,2,6,6-tetra-methyl-benzo[1,2-d;4,5-d']bis-[1,3]di-thiol-4-yl-methanol, 2, and electrophilic quenching with tri-methyl-silyl chloride. The current crystal structure reveals information about the reactivity of this compound and compares well with the structure reported for the unsubstituted parent compound 2 [Driesschaert et al. (2012 ▸). Eur. J. Org. Chem.33, 6517-6525]. The title compound 1 forms mol-ecular propellers and crystallizes in P [Formula: see text], featuring an unusually long Si-Car bond of 1.910 (3) Å. Moreover, the geometry at the central quaternary carbon is rather trigonal-pyramidal than tetra-hedral due to vast intra-molecular stress. One tri-methyl-silyl group is disordered over two positions in a 0.504 (4):0.496 (4) ratio and one S atom is disordered over two positions in a 0.509 (7):0.491 (7) ratio. The contribution of disordered diethyl ether solvent mol-ecule(s) was removed using the PLATON SQUEEZE (Spek, 2015 ▸) solvent masking procedure. These solvent mol-ecules are not considered in the given chemical formula and other crystal data.

Keywords: EPR; crystal structure; spin label; trityl radical; tri­aryl­methanol.

Grants and funding

This work was funded by Deutsche Forschungsgemeinschaft grant CRC813, project A6 to O. Schiemann.