The Bond Character of the Sn–Cl Bonds in the Hydrates of Tin (IV) Chloride

Abstract

(y=3, 4 and 5), were investigated by means of the nuclear quadrupole resonance (NQR) due to 35Cl and the Mossbauer effect due to 119Sn . The NQR-frequencies were observed at the temperature of liquid nitrogen and room temperature; they were found to range from 17.656 to 21.439MHz. The Mossbauer effect was investigated only at the temperature of liquid nitrogen; it resulted in isomer shifts ranging from 0.275 to 0.350mm/sec.The NQR-frequency and the isomer shift decreased with an increase in the number of water molecules in the hydrates, and the relationship between the NQR-frequency and the isomer shift was nearly linear. This relation was interpreted in terms of the transfer of the s-electrons of the tin atom to the chlorine atoms. Furthermore, it was revealed that there was a significant difference between the Sn-Cl bond of the hydrates and that of ammonium chlorostannate.It is well-known that tin(IV) chloride forms various hydrates but their structures have not been determined by any means except the Raman spectra.1) Tin(IV) chloride and its hydrates are suitable for investigating the Sn-Cl bond, since the electronic structures of the tin and chlorine atoms can be investigated by means of the Mossbauer effect due to 119Sn and the nuclear quadrupole resonance due to 35Cl.The molecular complexes of tin(IV) chloride with organic or inorganic compounds containing oxygen or nitrogen atoms have thus far investigated by means of NQR2,3) and the Mossbauer effect. [4][5][6][7][8]

Crystal Structures and Raman Spectra of cis‐[SnCl4(H2O)2]·2H2O, cis‐[SnCl4(H2O)2]·3H2O, [Sn2Cl6(OH)2(H2O)2]·4H2O, and [HL][SnCl5(H2O)]·2.5H2O (L=3‐acetyl‐5‐benzyl‐1‐phenyl‐4, 5‐dihydro‐1, 2, 4‐triazine‐6‐one oxime, C18H18N4O2)

“…It has been suggested on the basis of Raman spectra that the hydrates of tin(IV) chloride SnCl 4 ·xH 2 O (xϭ2,3,4,5 and 8) have trans-[SnCl 4 (H 2 O) 2 ] structural entities in the liquid state [1]. Similar results are concluded from 35 Cl nuclear quadrupole resonance spectra (NQR) of SnCl 4 ·2H 2 O and SnCl 4 ·3H 2 O in the solid state [2]. However, an X-ray diffraction study of SnCl 4 ·5H 2 O shows cis-[SnCl 4 (H 2 O) 2 ]·3H 2 O structure, in which the cis-octahedral units are linked to a three-dimensional network through hydrogen bonds involving lattice water [3].…”

“…Hydrates of tin(IV) chloride SnCl 4 ·xH 2 O (x ϭ 2,3,4,5 and 8) have been prepared by the reaction of SnCl 4 with water in the proper molar ratio [1,2]. The hydrate SnCl 4 · 2H 2 O was accidentally isolated during recrystallization of [Sn 2 Cl 8 {µ-C 3 H 6 (CO 2 Et) 2 } 2 ]·2CH 2 Cl 2 in dichloromethane [9].…”

“…The crown ethers act as secondsphere ligands. Octahedral [SnCl 4 (H 2 O) 2 ] units with cis water molecules are also found in [SnX 4 (H 2 O) 2 ]·2diox (Xϭ Cl, Br) [8] and [SnCl 4 (H 2 O) 2 ]·C 3 H 6 (CO 2 Et) 2 [9] according to X-ray crystallographic studies.…”

“…One crystal of [Sn 2 Cl 6 (OH) 2 2 ]·3diox has been obtained from a hot dioxane solution of an aged commercial sample of SnCl 2 ·2H 2 O [3] and as the product of the attempted recrystallization of SnCl 2 .diox from dioxane [10].…”

35Cl nuclear quadrupole resonance study of lattice dynamics in SnCl4⋅5H2O comprising uncoordinated water molecules

“…On the other hand, they observed two resonance lines for the pentahydrate at room temperature, but were not able to obtain NQR spectra at low temperatures due to the piezoelectric effect on the cooling process. 2 From their experimental results, three uncoordinated water molecules were identified in the tin ͑IV͒ chloride pentahydrate crystal, in addition to the octahedrally coordinated atomic arrangement of four Cl atoms and two H 2 O molecules around the tin ͑IV͒ atom. Although the configuration of the three uncoordinated water molecules is not clear, they may form hydrogen bonds with the tin chloride octahedra instead of forming direct bonds, and may occupy interstitial sites between the octahedra.…”