Trimethylsulfoxonium Explained

Trimethylsulfoxonium (abbreviated TMSO) is a cation with a formula (CH₃)₃SO⁺ consisting of a sulfur atom attached to three methyl groups and one oxygen atom. It has a net charge of +1.

Production

Refluxing dimethyl sulfoxide with methyl iodide can yield trimethylsulfoxonium iodide.

Reactions

Treated with sodium hydride, trimethylsulfoxonium forms dimethylsulfoxonium methylide.

Trimethylsulfoxonium can polymerise to yield polyethylene.^{[1] [2]}

Copper, zinc and palladium ions in water react with trimethylsulfoxonium and sodium hydroxide to form sulfur ylide complexes.^[3]

Properties

In the chloride, the sulfur-oxygen bond length is 1.436 Å, sulfur-carbon bond is 1.742. OSC angles are 112.6°, and CSC angles are 106.2°.^[4]

List of compounds

name	formula	crystal Å	volume	density	comment	reference
trimethylsulfoxonium phthalimide	[C<sub>3</sub>H<sub>9</sub>SO][C<sub>8</sub>H<sub>4</sub>NO<sub>2</sub>]	orthorhombic Pnma a=8.445 b=10.958 c=12.084 Z=4	1118.2		colourless	^[5]
Trimethylsulfoxonium nitrate						^[6]
Trimethylsulfoxonium tetraphenylborate	[(CH<sub>3</sub>)<sub>3</sub>SO]Ph4B	P21/m a=9.482 b=12.790 c=9.713 β=106.48° Z=2	1130	1.177
Trimethylsulfoxonium chloride	[(CH<sub>3</sub>)<sub>3</sub>SO]Cl				white; sublime 227°C
Trimethylsulfoxonium chromate
trimethylsulfoxonium tetrachloridocobaltate(II)	[(CH<sub>3</sub>)<sub>3</sub>SO]2CoCl4	monoclinic, P21/c a = 8.4397, b = 15.6692, c = 12.5989, β = 93.858°, Z = 4	1662.3		blue	^[7]
Trimethylsulfoxonium bromide
Trimethylsulfoxonium iodide	[(CH<sub>3</sub>)<sub>3</sub>SO]I				yellow; dec 170°C
	[(CH<sub>3</sub>)<sub>3</sub>SO]Cu2I3	Pnma				^[8]
	[(CH<sub>3</sub>)<sub>3</sub>SO]Ag2I3	Pnma
trimethyloxosulfonium trichloro-cadmate	[(CH<sub>3</sub>)<sub>3</sub>SO]CdCl3	orthorhombic Pnma a=6.688 b=10.147 c=13.446 Z=4	912.5	2.270
trimethyloxosulfonium tribromo-cadmate	[(CH<sub>3</sub>)<sub>3</sub>SO]CdBr3	orthorhombic Pnma a=6.946 b=10.543 c=13.782 Z=4	1009.3	2.928	colourless
bis(trimethylsulfoxonium) catena-poly[μ<sub>2</sub>-hexabromido-indium(III)sodium(I)]	[(CH<sub>3</sub>)<sub>3</sub>SO]2NaInBr6	orthorhombic, Pmn21, a = 10.5451, b = 7.1169, c = 13.7034, Z = 2	1028.42		colourless	^[9]
	[(CH<sub>3</sub>)<sub>3</sub>SO]PbBr3	orthorhombic Pnma a=7.5697 b=10.7768 c=13.9143 Z=4	1135.09	3.160	white	^[10]
	[(CH<sub>3</sub>)<sub>3</sub>SO]PbI3	orthorhombic Pnma a=7.8157 b=11.1996 c=14.3780 Z=4	1260.29	3.590	light yellow; band gap 2.30 eV	^[11]
	[(CH<sub>3</sub>)<sub>3</sub>SO]3Bi2Br9	orthorhombic Pnma a=7.0351 b=10.6613 c=13.9190	1043.98	3.004	light yellow
	[(CH<sub>3</sub>)<sub>3</sub>SO]3Bi2I9	orthorhombic Pnma a=7.4530 b=11.2169 c=14.4009	1203.92	3.383	red

Notes and References

1. Polyethylene from Trimethylsulfoxonium Halide in Water . Synfacts . August 2012 . 8 . 08 . 0845 . 10.1055/s-0032-1316727. 99933705 .
2. Luo . Jun . Lu . Fangfang . Shea . Kenneth J. . Hydrocarbon Waxes from a Salt in Water: The C1 Polymerization of Trimethylsulfoxonium Halide . ACS Macro Letters . 15 May 2012 . 1 . 5 . 560–563 . 10.1021/mz300140x. 35607061 .
3. Lin . Ivan J.B. . Hwan . Luchen . Shy . Hwai C. . Chen . M.C. . Wang . Y. . The synthesis of sulfur ylide complexes of palladium, zinc and copper in water . Journal of Organometallic Chemistry . November 1986 . 315 . 1 . 135–142 . 10.1016/0022-328X(86)80418-1.
4. Knop . Osvald . Cameron . T. Stanley . Bakshi . Pradip K. . Linden . Antony . Roe . Stephen P. . 1994-08-01 . Crystal chemistry of tetraradial species. Part 5. Interaction between cation lone pairs and phenyl groups in tetraphenylborates: crystal structures of Me 3 S +,Et 3 S +,Me 3 SO +,Ph 2 I +, and 1-azoniapropellane tetraphenylborates . Canadian Journal of Chemistry . en . 72 . 8 . 1870–1881 . 10.1139/v94-238 . 0008-4042.
5. Mallah . Eyad . Abu-Salem . Qutaiba . Dayyih . Wael Abu . Hamad . Mohammed . Steimann . Manfred . Maichle-Mössmer . Caecilia . 2011-01-01 . Crystal structure of trimethylsulfoxonium phthalimide, [C3H9SO][C8H4NO2] ]. Zeitschrift für Kristallographie - New Crystal Structures . 226 . 3 . 10.1524/ncrs.2011.0155 . 2197-4578. free .
6. Puget . R. . Jannin . M. . de Brauer . C. . Perret . R. . 1991-09-15 . Structures oftrimethyloxosulfonium salts. V. The catena-tri-μ-chloro-cadmate and the catena-tri-μ-bromo-cadmate . Acta Crystallographica Section C Crystal Structure Communications . 47 . 9 . 1803–1805 . 10.1107/S0108270190013701. 1991AcCrC..47.1803P .
7. Zhong . Xin . Zhou . Junyan . Hao . Munan . 2020-06-25 . Crystal structure of trimethylsulfoxonium tetrachloridocobaltate(II) [(CH 3) 3 SO] 2 CoCl 4 ]. Zeitschrift für Kristallographie - New Crystal Structures . en . 235 . 4 . 1001–1002 . 10.1515/ncrs-2020-0159 . 2197-4578. free .
8. Pinky . Tamanna . Popy . Dilruba A. . Zhang . Zheng . Jiang . Jie . Pachter . Ruth . Saparov . Bayram . Synthesis and Characterization of New Hybrid Organic–Inorganic Metal Halides [(CH 3) 3 SO]M 2 I 3 (M = Cu and Ag) . Inorganic Chemistry . 18 January 2024 . 10.1021/acs.inorgchem.3c04119.
9. Jin . Shifeng . Lu . Jiali . 2023-12-15 . The crystal structure of bis(trimethylsulfoxonium) catena -poly[μ 2 -hexabromido-indium(III)sodium(I)] C 6 H 18 O 2 S 2 NaInBr 6 ]. Zeitschrift für Kristallographie - New Crystal Structures . en . 238 . 6 . 1171–1173 . 10.1515/ncrs-2023-0377 . 1433-7266. free .
10. Pipitone . Candida . Giannici . Francesco . Martorana . Antonino . García-Espejo . Gonzalo . Carlotto . Silvia . Casarin . Maurizio . Guagliardi . Antonietta . Masciocchi . Norberto . 2021-06-03 . Heterovalent Bi III /Pb II Ionic Substitution in One-Dimensional Trimethylsulfoxonium Halide Pseudo-Perovskites (X = I, Br) . The Journal of Physical Chemistry C . en . 125 . 21 . 11728–11742 . 10.1021/acs.jpcc.1c02571 . 1932-7447. 10447/519176 . free .
11. Rahman . Md. Mahbubur . Ge . Chuang-ye . Yoo . Kicheon . Lee . Jae-Joon . Aqueous phase synthesis of trimethylsulfoxonium lead triiodide for moisture-stable perovskite solar cells . Materials Today Energy . September 2021 . 21 . 100803 . 10.1016/j.mtener.2021.100803. free .