Bis(triphenylphosphine)rhodium carbonyl chloride

Bis(triphenylphosphine)rhodium carbonyl chloride
Names
	Other names Bis(triphenylphosphine)rhodium(I) carbonyl chloride
Identifiers
CAS Number	13938-94-8 ; trans: 15318-33-9 ; cis: 16353-77-8 ;
3D model (JSmol)	Interactive image;
EC Number	237-712-8;
PubChem CID	11319966;
UNII	trans: 100LRS254G ; cis: 84NQM9263V;
	InChI InChI=1S/2C18H15P.CO.ClH.Rh/c21-4-10-16(11-5-1)19(17-12-6-2-7-13-17)18-14-8-3-9-15-18;1-2;;/h21-15H;;1H;/p-1 Key: RMJBMLFXJWHQJH-UHFFFAOYSA-M;
	SMILES [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.[Cl-].[Rh];
Properties
Chemical formula	RhCl(CO)[P(C6H5)3]2
Molar mass	690.94
Appearance	yellow solid
Hazards
	GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302, H312, H315, H319, H332
Precautionary statements	P261, P264, P270, P271, P273, P280, P301+P312, P302+P352, P304+P312, P304+P340, P305+P351+P338, P312, P321, P322, P330, P332+P313, P337+P313, P362, P363, P403+P233, P405, P501
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Bis(triphenylphosphine)rhodium carbonyl chloride is the organorhodium complex with the formula [RhCl(CO)(PPh₃)₂]. This complex of rhodium(I) is a bright yellow, air-stable solid. It is the Rh analogue of Vaska's complex, the corresponding iridium complex. With regards to its structure, the complex is square planar with mutually trans triphenylphosphine (PPh₃) ligands. The complex is a versatile homogeneous catalyst.^[1]

Synthesis and reactions

Bis(triphenylphosphine)rhodium carbonyl chloride was originally prepared by treating Rh₂Cl₂(CO)₄ with triphenylphosphine.^[2] However, it is typically produced by the carbonylation of Wilkinson's catalyst:^[3]

RhCl[P(C₆H₅)₃]₃ + CO → RhCl(CO)[P(C₆H₅)₃]₂ + P(C₆H₅)₃

In homogeneous catalysis, this conversion is typically an undesirable side-reaction since [RhCl(CO)(PPh₃)₂] is a poor hydrogenation catalyst.

Bis(triphenylphosphine)rhodium carbonyl chloride is the precursor to tris(triphenylphosphine)rhodium carbonyl hydride, an important catalyst for hydroformylation.

RhCl(CO)[P(C₆H₅)₃]₂ + NaBH₄ + P(C₆H₅)₃ → RhH(CO)[P(C₆H₅)₃]₃ + NaCl + BH₃

References

^ Kikukawa, Kiyoshi; Westcott, Stephen A.; Croatt, Mitchell P.; Williams, Travis J.; Wender, Paul A.; Li, Yiming; Jiang, Xuefeng (2015). "Carbonyl(chloro)bis(triphenylphosphine)rhodium(I)". e-EROS Encyclopedia of Reagents for Organic Synthesis. pp. 1–22. doi:10.1002/047084289X.rc021.pub3. ISBN 978-0-470-84289-8.
^ Vallarino, L. (1957). "Carbonyl Complexes of Rhodium. I. Complexes with Triarylphosphines, Triarylarsines, and Triarylstibines". Journal of the Chemical Society: 2287–92. doi:10.1039/jr9570002287.
^ D. Evans; J. A. Osborn; G. Wilkinson (2007). "Trans -Carbonylchlorobis(Triphenyl-Phosphine)Rhodium and Related Complexes". trans-Carbonylchlorobis(Triphenylphosphine)Rhodium and Related Complexes. Inorganic Syntheses. Vol. 28. pp. 79–80. doi:10.1002/9780470132593.ch18. ISBN 978-0-470-13259-3.

[1] Kikukawa, Kiyoshi; Westcott, Stephen A.; Croatt, Mitchell P.; Williams, Travis J.; Wender, Paul A.; Li, Yiming; Jiang, Xuefeng (2015). "Carbonyl(chloro)bis(triphenylphosphine)rhodium(I)". e-EROS Encyclopedia of Reagents for Organic Synthesis. pp. 1–22. doi:10.1002/047084289X.rc021.pub3. ISBN 978-0-470-84289-8.

[2] Vallarino, L. (1957). "Carbonyl Complexes of Rhodium. I. Complexes with Triarylphosphines, Triarylarsines, and Triarylstibines". Journal of the Chemical Society: 2287–92. doi:10.1039/jr9570002287.

[3] D. Evans; J. A. Osborn; G. Wilkinson (2007). "Trans -Carbonylchlorobis(Triphenyl-Phosphine)Rhodium and Related Complexes". trans-Carbonylchlorobis(Triphenylphosphine)Rhodium and Related Complexes. Inorganic Syntheses. Vol. 28. pp. 79–80. doi:10.1002/9780470132593.ch18. ISBN 978-0-470-13259-3.

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