Crystal structure of sodium thiosulfate dihydrate and comparison to the pentahydrate

Abstract

Na2S2O3·2H2O has been mentioned in the literature for more than a hundred years and pure samples were prepared and investigated, however, no structural data except for a set of lattice parameters were known to date. Now crystals of this compound have been grown at the surface of an aqueous solution of Na2S2O3 and the structure has been determined at 200 and 100 K. Na2S2O3·2H2O crystallizes in the space group P21/n with two formula units in the asymmetric unit and all atoms occupying general positions. The sodium cations are five- to seven-coordinate by thiosulfate anions and water molecules and the anions act as mono- and bidentate ligands. In the extended structure, the thiosulfate anions and water molecules are connected by O—H...O and O—H...S hydrogen bonds of medium strength to form corrugated layers, which are linked by sodium cations. For comparison, the crystal structure of Na2S2O3·5H2O has been determined at the same conditions, i.e. for the first time below room temperature.

Generation of Thiosulfate, Selenite, Dithiosulfite, Perthionitrite, Nitric Oxide, and Reactive Chalcogen Species by Binuclear Zinc(II)-Chalcogenolato/-Polychalcogenido Complexes

“…111.03°) and < S–S–O angles (106.4(2)-108.7(2)°, av. 107.87°) of the coordinated S 2 O 3 2– ion in 6 are consistent with the average < O–S–O angles (110.30°) and < S–S–O angles (108.63°) reported for Na 2 S 2 O 3 ·2H 2 O …”

“…Interestingly enough, the treatment of 2a and 5a with O 2 allowed the isolation of a S 2 O 3 2− bridged binuclear Zn(II) complex, [Zn 2 (HPTP)(μ-S 2 O 3 )] 1+ (6) and a selenite (SeO 3 2− ) bridged binuclear Zn(II) complex, [Zn 2 (HPTP)(μ-SeO 3 )] 1+ (7), respectively (Scheme 3). The identity and purity of 6 and 7 were confirmed by MS, 1 H and 13 C NMR spectroscopy (Figures S65−S70 99 The result of the reaction of 2a with O 2 is in line with the proposed alternate mechanism for the SOR activity which involves the direct redox reaction between the coordinated polysulfide chain and O 2 to generate SO . 97,98 Moreover, the difference in the identity of the products obtained from 2a (S 2 O 3 2− ) and 5a (SeO 3 2− ) indicates the importance of the presence/absence of a "neutral" electrophilic chalcogen atom (S/Se) in the starting complexes.…”

“…In 6 , the S 2 O 3 2– ion coordinates the zinc centers by a sulfur (S1) and an oxygen (O2) atom with Zn2–S1 and Zn1–O2 distances of 2.378(2) Å and 2.014(5) Å, respectively. The S–O distances within the coordinated S 2 O 3 2– ion are 1.500 Å (S2–O2), 1.454(5) Å (S2–O3) and 1.460(5) Å (S2–O4), which are quite similar to the S–O distances of 1.4722(4)-1.4841(4) Å and 1.4665(4)-1.4867(4) Å in Na 2 S 2 O 3 ·2H 2 O (two independent thiosulfate anions were observed) and in Na 2 S 2 O 3 ·5H 2 O, respectively . The S–S distance (S1–S2) of 2.038(2) Å in 6 is again similar to the S–S distances of 2.0047 (2) Å, 2.0078 (2) Å and 2.0266 (1) Å in Na 2 S 2 O 3 ·2H 2 O and Na 2 S 2 O 3 ·5H 2 O, respectively .…”

“…The S–O distances within the coordinated S 2 O 3 2– ion are 1.500 Å (S2–O2), 1.454(5) Å (S2–O3) and 1.460(5) Å (S2–O4), which are quite similar to the S–O distances of 1.4722(4)-1.4841(4) Å and 1.4665(4)-1.4867(4) Å in Na 2 S 2 O 3 ·2H 2 O (two independent thiosulfate anions were observed) and in Na 2 S 2 O 3 ·5H 2 O, respectively . The S–S distance (S1–S2) of 2.038(2) Å in 6 is again similar to the S–S distances of 2.0047 (2) Å, 2.0078 (2) Å and 2.0266 (1) Å in Na 2 S 2 O 3 ·2H 2 O and Na 2 S 2 O 3 ·5H 2 O, respectively . The S–S and S–O distances are also similar to the average S–S and S–O distances of 2.043 and 1.458 Å, respectively, reported for several metal-complexes where the S 2 O 3 2– ion is bonded to metal by sulfur and oxygen atom. − The < O–S–O angles (109.1(3)-113.7(3)°, av.…”