Dimethyltin dichloride
Chemical compound
From Wikipedia, the free encyclopedia
Dimethyltin dichloride is an organotin compound with the formula (CH3)2SnCl2. It is a white crystalline solid.
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| Names | |
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| IUPAC name
Dichloro(dimethyl)stannane[1] | |
| Other names | |
| Identifiers | |
3D model (JSmol) |
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| ChemSpider | |
| ECHA InfoCard | 100.010.945 |
| EC Number |
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PubChem CID |
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| UNII | |
CompTox Dashboard (EPA) |
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| Properties | |
| (CH3)2SnCl2 | |
| Molar mass | 219.68 g·mol−1 |
| Appearance | White crystalline solid[1][3] |
| Density | 1.397 g/cm3[3] |
| Melting point | 101–106 °C (214–223 °F; 374–379 K)[4] |
| Boiling point | 189 °C (372 °F; 462 K)[4] Decomposition at 500 °C (932 °F)[2] |
| 823 g/l at 20 °C[4] | |
| Structure | |
| Tetrahedral at Sn | |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards |
Highly toxic |
| GHS labelling: | |
   | |
| Danger | |
| H301, H311, H314, H330, H361d, H372 | |
| P203, P260, P262, P264, P270, P271, P280, P284, P301+P316, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P354+P338, P316, P318, P319, P320, P321, P330, P361+P364, P363, P403+P233, P405, P501 | |
| Lethal dose or concentration (LD, LC): | |
LD50 (median dose) |
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| Related compounds | |
Related compounds |
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Synthesis
Dimethyltin dichloride can be synthesized by reaction of tin and methyl chloride in the presence of trialkylamine NR3 as a catalyst.[5]
- Sn + 2 CH3Cl → (CH3)2SnCl2
Dimethyltin dichloride can also be prepared in high yield from molten tin and methyl chloride in a sodium tetrachloroaluminate salt melt at 280 °C (536 °F). The reaction is initiated by the addition of a catalytic amount of tin dichloride. In the first step, methyl chloride reacts with tin dichloride to form methyltin trichloride CH3SnCl3, which is in the second step reduced to methyltin(II) chloride CH3SnCl with tin, releasing tin dichloride. In the third step, this reacts with another molecule of methyl chloride to form dimethyltin dichloride.[6]
- 1. SnCl2 + CH3Cl → CH3SnCl3
- 2. CH3SnCl3 + Sn → CH3SnCl + SnCl2
- 3. CH3SnCl + CH3Cl → (CH3)2SnCl2
The gross equation is:
- Sn + 2 CH3Cl → (CH3)2SnCl2
Dimethyltin dichloride can also be prepared by the Kocheshkov reaction between tetramethyltin and tin(IV) chloride.[7]
- SnCl4 + Sn(CH3)4 → 2 (CH3)2SnCl2
Properties
Reactions
Dimethyltin dichloride dissociates in water, creating (CH3)2Sn(H2O)x2+ cations and Cl− anions.[11]
- (CH3)2SnCl2 + x H2O ⇌ (CH3)2Sn(H2O)x2+ + 2 Cl−
- (CH3)2Sn(H2O)x2+ + H2O ⇌ (CH3)2Sn(OH)(H2O)x−1+ + H3O+
It forms adducts with Lewis bases such as pyridine and 1,10-phenanthroline.[12]
Dimethyltin dichloride reacts with hydrogen fluoride to give a mixed halide dimethyltin chloride fluoride (CH3)2SnClF. It reacts with trimethyliodosilane (CH3)3SiI to give dimethyltin diiodide (CH3)2SnI2.[13]
Structure
Dimethyltin dichloride is tetrahedral at Sn. The distances and angles between atoms are as follows:[14]
- d(Sn-C) = 212.0(7) pm
- d(Sn-Cl) = 238.9(2) pm
- ∠(Cl-Sn-Cl) = 98.60(9)°
- ∠(C-Sn-C) = 142.2(4)°
The length of the intermolecular tin-chlorine distance was determined to be 343.3 pm. This value shows that dimethyltin dichloride has a strong intermolecular force due to small steric hindrance of the tin atom by the two methyl groups.[14]
Uses
Safety
Dimethyltin dichloride, like many other organotin compounds, is toxic and must be handled with care. Its toxic effects primarily target the kidneys and the central nervous system. At higher doses targets also the liver, adrenal glands, spleen, thymus, bladder, testes and epididymis.[17] It can cause severe skin burns and serious eye damage.[1]