Carbonylchlorohydrotris(triphenylphosphine)osmium

Carbonylchlorohydrotris (triphenylphosphine) osmium (II)
Identifiers
CAS Number	16971-31-6 ;
3D model (JSmol)	Interactive image;
ChemSpider	78388;
EC Number	241-050-5;
PubChem CID	86891;
	InChI InChI=1S/3C18H15P.CO.ClH.Os.H/c31-4-10-16(11-5-1)19(17-12-6-2-7-13-17)18-14-8-3-9-15-18;1-2;;;/h31-15H;;1H;;/q;;;;;+2;-1/p-1 Key: XUWSMTCLGDHTRB-UHFFFAOYSA-M;
	SMILES [H-].[C-]#[O+].C1=CC=C(C=C1)P(C2=CC=CC=C2)C3=CC=CC=C3.C1=CC=C(C=C1)P(C2=CC=CC=C2)C3=CC=CC=C3.C1=CC=C(C=C1)P(C2=CC=CC=C2)C3=CC=CC=C3.[Cl-].[Os+2];
Properties
Chemical formula	OsHCl(CO)(PPh3)3
Molar mass	1041.6 g/mol
Appearance	White crystalline solid.
Melting point	179-183°C
Solubility in water	insoluble
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Carbonylchlorohydrotris(triphenylphosphine)osmium is a coordination complex consisting of one carbon monoxide ligand, hydrogen, chlorine, and three triphenylphosphine ligands all coordinated to an osmium(II) center. It is a precursor to osmium nitrosyl complexes. Its chemical formula can be written as OsHCl(CO)(PPh₃)₃ or OsHCl(CO)[P(C₆H₅)₃]₃

Synthesis

It is prepared by reacting ammonium hexachloroosmate(IV) with triphenylphosphine in the presence of 2-(2-methoxyethoxy)ethanol at 190°C.^[1]

(NH₄)₂OsCl₆ + 4PPh₃ ^{2-(2-methoxyethoxy)ethanol}
_{———————————→} OsHCl(CO)(PPh₃)₃ + 2NH₄Cl + 2PPh₃Cl₂

Another method of preparing it is by adding a solution of sodium hexachloroosmate and formalin to a boiling solution of triphenylphosphine in 2-methoxyethanol.^[2]

Na₂OsCl₆•6H₂O + 3(C₆H₅)₃P ^formalin
_———→ OsHCl(CO)[P(C₆H₅)₃]₃

It can also be prepared by reacting OsCl₃(PPh₃)₃ with formaldehyde.^[3]

Properties

It forms white crystalline prisms. While it is insoluble in water, alcohols, and non-aromatic hydrocarbons, it is moderately soluble in other organic solvents such as benzene, chloroform, dichloromethane, and acetone. When heated to its melting point in air, it reacts with oxygen and decomposes. In a sealed container of nitrogen it melts at 290°C with decomposition. The infrared spectrum has a line at 2099 cm⁻¹.^[1]^[2]

Reactions

It reacts with n-methyl-n-nitrosotoluene sulfonamide to yield Os(NO)(CO)Cl(PPh₃)₂, which in turn can react with oxygen and triphenylphosphine to produce OsCl(NO)(PPh₃)₃.^[3]

When treated with sodium hydroxide in a boiling solution of 2-methoxyethanol, it reacts to form OsH₂(CO)[P(C₆H₅)₃]₃^[2]

References

^ ^a ^b ^c Chiririwa, Haleden; Muzenda, Edison (November 2014). "The Preparation and Characterisation of Osmium (IV), Osmium (II), and Osmium (0) Complexes from Refinery Materials" (PDF). International Conference on Chemical Engineering & Advanced Computational Technologies (ICCEACT): 32–35. Retrieved 17 July 2025.
^ ^a ^b ^c Parshall, George (1974). Inorganic Syntheses (PDF). Vol. 15. McGraw-Hill Book Company. pp. 53–54. Retrieved 17 July 2025.
^ ^a ^b Cotton, S. A. (1997). "Ruthenium and Osmium". Chemistry of Precious Metals (PDF). Rutland, UK: Blackie Academic & Professional. pp. xi, 67. Retrieved 17 July 2025.

[Prep-1] Chiririwa, Haleden; Muzenda, Edison (November 2014). "The Preparation and Characterisation of Osmium (IV), Osmium (II), and Osmium (0) Complexes from Refinery Materials" (PDF). International Conference on Chemical Engineering & Advanced Computational Technologies (ICCEACT): 32–35. Retrieved 17 July 2025.

[Synth-2] Parshall, George (1974). Inorganic Syntheses (PDF). Vol. 15. McGraw-Hill Book Company. pp. 53–54. Retrieved 17 July 2025.

[Cotton-3] Cotton, S. A. (1997). "Ruthenium and Osmium". Chemistry of Precious Metals (PDF). Rutland, UK: Blackie Academic & Professional. pp. xi, 67. Retrieved 17 July 2025.

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