Wiesław Wojnowski

A study of chirality in bis(1,2-dimethoxyethane-κ2O,O′)sodium bis(tri-tert-butoxysilanethiolato-κ2O,S)sodate

This work presents an analysis of self-assembly of a complex molecule from simpler ions, some of which are asymmetric, and is an example of a sodium silanethiolate. The tri-tert-butoxysilanethiolate anion has two helical conformers (P and M), so aggregation of silanethiolates can proceed with recognition of chirality. Alkali metal silanethiolates can form cyclic solvated oligomers (e.g. dimers) or complexes such as sodates with anions of general formula R2Na(-). We note that all known sodates (and lithiates) contain both ligands of the same helicity in the anion, whereas in the dimers the metal atoms are coordinated by silanethiolate ligands of different helicity. The title compound, a new example of a sodate, [Na(C4H10O2)2][Na(C12H27O3SSi)2] or [Na{((t)BuO)3SiS}2][Na(DME)2] (DME is 1,2-dimethoxyethane), is built up of separate ion pairs with no significant interactions. The anion is formed from an Na atom O,S-chelated by two silanethiolate ligands of the same helicity (both P or both M), while the cation contains an Na atom solvated by two DME molecules. Because the structure is centrosymmetric, equal numbers of both conformational enantiomers are present in the crystal lattice.

Potassium Tri-tert-butoxysilanethiolates: Synthesis, Properties, and Crystal and Molecular Structures of [( t BuO)3SiSK]6[THF]2· 2THF, {[( t BuO)3SiS]2K2} n , and [( t BuO)3SiSK]4[H2O]4· C6H6

The synthesis and characterization of a family of potassium silanethiolates is described. [( t BuO)3SiSK]6[THF]2· 2THF ( 1 ), {[( t BuO)3SiS]2K2} n ( 2 ), and [( t BuO)3SiSK]4[H2O]4· C6H6 ( 3 ) were synthesized by treatment of ( t BuO)3SiSH with potassium metal in various solvents. The target molecules were characterized by single crystal X-ray crystallography. Compounds 1 , 2 , and 3 form hexameric, polymeric, and tetrameric units correspondingly, in the solid state. [( t BuO)3SiSK]6[THF]2· 2THF contains three, differently coordinated potassium ions and crystallizes in the space group P21/c, a = 15.227(4), b = 14.650(5), c = 32.067(9) Å, β = 117.001(18)°, V = 6374(3) Å3. {[( t BuO)3SiS]2K2} n crystallizes in the space group P-1, a = 11.6305(14), b = 13.348(3), c = 13.531(4) Å, α = 67.27(2)°, β = 76.064(16)°, γ = 88.706(14)°, V = 1874.6(8) Å3. [( t BuO)3SiSK]4[H2O]4· C6H6 crystallizes in the space group P-4b2, a = 20.854(3), b = 20.854(3), c = 9.283(2) Å, α = β = γ = 90°, V = 4037,1(12) Å3.

Ammonium tri-tert-butoxy­silanethiol­ate

The cations and anions of the title salt, NH4 +·C12H27O3SSi−, are linked by N—H⋯S and N—H⋯O hydrogen bonds into a linear chain that runs along the a axis of the monoclinic unit cell. The asymmetric unit contains two cations and two anions.

The first compound with an unusual type of anion, [Li(SR)2]–: bis­(μ2-aqua-d2)tetra­kis(aqua-d2)dilithium(I) bis­[bis­(tri-tert-butoxy­silanethiol­ato-κ2O,S)lithate(I)] dihydrate-d2

The title complex, [Li2(D2O)6][Li(C9H27SSiO3)2]2.2D2O, is the first compound with an S-M bond (M = alkali metal) within an unusual type of lithate anion, [Li(SR)2]- {where R is Si[OC(CH3)3]3}. There is a centre of symmetry located in the middle of the Li2O2 ring of the cation. All Li atoms are four-coordinate, with LiO4 (cations) and LiO2S2 (anions) cores. The singly charged [Li(SR)2]- anions are well separated from the doubly charged [Li2(D2O)6]2+ cations; the distance between Li atoms from differently charged ions is greater than 5 A. Both ion types are held within an extended network of O-D...O and O-D...S hydrogen bonds.

N,N,N-Trimethyl-N-(methyl 5-de­oxy-2,3-O-iso­propyl­idene-β-d-ribo­furan­osid-5-yl)ammonium 4-methyl­benzene­sulfonate sesquihydrate

The structure of the title compound, [C12H24NO4][C7H7O3S]·1.5H2O, contains alternating layers parallel to (001) of hydrophobic and polar character, stabilized by C—H⋯O hydrogen bonding. The furan ring adopts an envelope conformation with the C(OMe) atom as the flap, and the dioxolane ring is twisted about one of the O—C(methine) bonds. A comparison to related compounds is presented. The tosylate-O atoms were disordered over two positions with the major component having a site occupancy factor = 0.566 (12). The structure was refined as a rotary twin with regard to rotation about the c axis with the contribution of the second component being 0.0048 (6). Solvate water molecules are highly disordered and were removed using the SQUEEZE procedure; the unit cell characteristics take into account the presence of the disordered solvent. High-resolution 1H and 13C NMR spectroscopic data are also presented.