15956-28-2 Usage
Description
Rhodium(II) acetate dimer, also known as emerald green powder, is a highly effective catalyst with a variety of applications in chemical reactions. It is characterized by its emerald green color and solubility in methanol and water. Rhodium(II) acetate dimer is particularly useful in differentiating ribonucleosides and deoxynucleosides, as well as in the functionalization of fullerenes into polymers.
Uses
Used in Catalyst Applications:
Rhodium(II) acetate dimer is used as a catalyst for ylide formation, cyclopropanation of alkenes, oxidation of alcohols, cyclization reactions involving -diazo carbonyl groups, and insertion into C-H and X-H bonds (X-H is NH, SH, or OH). Its reactivity and utility make it a valuable component in various chemical processes.
Used in Pharmaceutical Industry:
Rhodium(II) acetate dimer is used as a catalyst in the preparation of molybdenum triisopropylbenzoate isonicotinate, which maintains ambivalent properties. This application is particularly relevant in the development of pharmaceutical compounds and their synthesis.
Used in Chemical Synthesis:
Rhodium(II) acetate dimer serves as an efficient catalyst for hydrogen transfer from 2-propanol to cyclohexanone and other unsaturated compounds. This application is crucial in the synthesis of various organic compounds and materials.
Preparation
Rhodium(II) acetate dimer synthesis: A suspension of 10.0g. of Rh(OH)3.H20 in 400 ml. of glacial acetic acid dissolved upon refluxing for 18 hr. to give a deep emerald-green solution. Most of the acetic acid was evaporated on a steam bath; remaining traces mere removed by heating the residue at 120° for 1hr. The residue was then extracted with boiling acetone until the extract was colorless rather than bluish green. The extract was quickly passed through a fritted glass filter, concentrated on a steam bath to 1/3 its original volume, and placed in the freezing compartment of a refrigerator for 18hr. The resulting large dark green crystals were collected on a filter, washed with small portions of ice-cold acetone, and dried at 110°. When first collected, the product is the weak adduct [Rh(OOCCH3)2(CH3)2C0]2; however, acetone is lost fairly readily at room temperature and immediately in the drying oven; yield, 6.2g. (48%).
Reactions
Catalyst for insertion into C-H and X-H bonds.Catalyst for Ylide generation.Doyle Kirmse Reaction of Allylic Sulfides with Diazoalkane.Claisen rearrangement.Epoxides from aldehydes.Synthesis of aziridines from allylic N-tosyloxycarbamates.Rh/NHC catalyzed direct intermolecular arylation of C-H bonds.Chiral Bronsted acid-Rh catalyzed three component reactions of diazo compounds with alcohols and imines.Rh-catalyzed cyclopropenations of ynamides.Tandem asymmetric aza-Darzens/ring-opening reactions.
Purification Methods
Dissolve 5g of the salt in boiling MeOH (ca 600mL) and filter. Concentrate it to 400mL and chill overnight at ca 0o to give dark green crystals of the MeOH adduct. Concentration of the mother liquors gives a further crop of [Rh(OAc)2]2.2MeOH. The adduct is then heated at 45o in a vacuum for 2hours (all MeOH is lost) to leave the emerald green crystals of the actetate. [Legzdins et al. J Chem Soc (A) 3322 1970.] Alternatively dissolve the acetate in glacial AcOH and reflux for a few hours to give an emerald green solution. Evaporate most of the AcOH on a steam bath, then heat the residue at 120o/1hour. Extract the residue with boiling Me2CO. Filter, concentrate to half its volume and keep at 0o/18hours. Collect the crystals, wash them with ice cold Me2CO and dry them at 110o. It is soluble in most organic solvents with which it forms adducts including Me3N and Me2S and gives solutions with different colours varying from green to orange and red. [UV: Johnson et al. Inorg Chem 2 960 1963, Beilstein 1 H 124.]
Check Digit Verification of cas no
The CAS Registry Mumber 15956-28-2 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,5,9,5 and 6 respectively; the second part has 2 digits, 2 and 8 respectively.
Calculate Digit Verification of CAS Registry Number 15956-28:
(7*1)+(6*5)+(5*9)+(4*5)+(3*6)+(2*2)+(1*8)=132
132 % 10 = 2
So 15956-28-2 is a valid CAS Registry Number.
InChI:InChI=1/4C2H4O2.2Rh/c4*1-2(3)4;;/h4*1H3,(H,3,4);;
15956-28-2Relevant articles and documents
A hardwon dirhodium paddlewheel with guanidinate type (hpp) bridging ligands
Berry, John F.,Cotton, F. Albert,Huang, Penglin,Murillo, Carlos A.,Wang, Xiaoping
, p. 3713 - 3715 (2005)
A dirhodium paddlewheel compound which has a Rh25+ core enveloped by four guaninate ligands was prepared. The ligand itself was incorporated into paddlewheel compounds of eleven different metal atoms. Considering the instability the tetraacetate precursor, compound 1 is remarkably stable in crystalline form and remains unchanges after exposure to air for several days. In THF solution the brownish color changes rapidly to purple because of axial coordination by solvent molecules.
