Rhodium trichloride trihydrate

A solution of rhodium trichloride trihydrate (2 g) in hot ethanol (70 ml) is added to a solution of freshly recrystallized triphenylphosphine (12 g) in hot... 

Rhodium trichloride trihydrate (1.00 g, 3.80 mmol) was dissolved in water (5.0 ml) with heating (70°C). A solution of triphenylphosphine (1.95 g, 7.43 mmol) in acetone (25.0 ml) was then added under a nitrogen atmosphere in the course of 20 min. After 10 min hydrazine hydrate (1.90 ml 39.09 mmol) was added with stirring and the mixture was heated at reflux temperature for 3 hours, then kept at 45°C for a further 1 hour. The crystalline solid was filtered off under nitrogen and washed with a little acetone and then with diethyl ether. 1.05 g of an orange-coloured solid were obtained. 

Benzenetellurolato-rhodium complexes were isolated when rhodium trichloride trihydrate and diphenyl tellurium were reacted in ethanol in the presence of formaldehyde. The benzenetellurolate ligand was formed by cleavage of one Te - C bond in diphenyl tellurium3. 

Benzenctellurolatobis[diphenyl teUurium]rhodium Dicbloride3 A solution of 2.0 g (7.6 mmol) of rhodium trichloride trihydrate in 120ml of hot ethanol is added to a refluxing solution of 7.75 g (27.5 mmol) of diphenyl tellurium in 250 ml of ethanol, refluxing is continued for 5 min, and 20 ml of 37% aqueous formaldehyde are added. The mixture is heated under reflux for 24 h, cooled to 0°, and filtered. The red solid is washed with hexane and dried yield 5.25 g (73%) dec. 149°. 

Rhodium trichloride trihydrate (1.0 g, 0.0038 mole) dissolved in 30 mL of water is placed in a 250-mL, round-bottomed flask, fitted with a condenser. The solution is heated to boiling, and 0.6 mL of ethylenediamine (0.01 mole) dissolved in SO mL of H2 O is added through the top of the condenser, in 5-mL increments, at 2-minute intervals. The yellow solution is allowed to heat at reflux for an additional 1S minutes. Then it is allowed to cool slightly, but while it is still hot (about 60°) 0.02 g of activated charcoal is added. The mixture is filtered (paper) and the filtrate is concentrated under vacuum to a volume of 30 mL. Concentrated nitric acid (10 mL) is added to the solution, which is kept, with occasional shaking, for 3 hours. A crystalline golden yellow precipitate forms. This is collected, washed with ice-cold water, ethanol, acetone, and diethyl ether and air dried. Yield 560 mg (40%). Anal. Calcd. C, 13.5 H, 4.5 ... 

Commercial rhodium trichloride trihydrate (5.0 g.) and sodium acetate trihydrate (10.0 g.) in glacial acetic acid (100 ml.) and absolute ethanol (100 ml.) were gently refluxed under nitrogen for an hour. 

The hexanuclear carbonyl Rh6(CO)ie was first prepared by treating anhydrous rhodium trichloride with carbon monoxide at 200 atm for several hours in the presence of a halogen acceptor such as cadmium, copper powder, silver, or zinc at temperatures of 80-230°.i At temperatures of 50-80°, the main product was Rh4(CO)i2. Optimum yields (80-90 %) of Rh6(CO)i6 are obtained by allowing methanolic solutions of rhodium trichloride trihydrate to react with carbon monoxide at 40 atm and 60°. Recently, however, there have been reports - of new high-yield syntheses of rhodium cluster carbonyls which require only ambient pressures of carbon monoxide. Chini and Martinengo have obtained Rh6(CO)i6 and Rh4(CO)i2 in high yield from the reaction of Rh2(CO)4Cl2 with carbon monoxide at atmospheric pressure and room temperature. 

Tris[benzenetelIurolato]rhodiuin A solution of 0.415 g (1.58 mmol) of rhodium trichloride trihydrate in 40 ml of hot ethanol is added to a boiling solution of 4.5 g (15.9 mmol) of diphenyl tellurium in 160 ml of ethanol. To this mixture are added in sequence 16 w/ of 40% aqueous formaldehyde and a solution of 1.28 g of potassium hydroxide in 40 ml of hot ethanol. The resultant mixture is heated under reflux for 30 min, cooled to 20°, and the dark brown solid is filtered yield 0.95 g (84%) dec. 155°. 

A 1000-mL two-necked flask equipped with a frit diffuser tube (CO inlet), a two-way stopcock (CO outlet) and a magnetic stirring bar is used as the reactor. Rhodium trichloride trihydrate (2.63 g, 10.0mmol) and potassium chloride (2.24 g, 30.0 mmol) are dissolved in 500 mL of water in the reactor. Copper powder (2g) is added, and the solution is bubbled with CO for 12 h with stirring at room temperature. To the resultant solution is added 2.94 g of trisodium citrate dihydrate, and stirring is continued for an additional 12 h under a CO atmosphere. The precipitate is collected under N2 and extracted with CO saturated hexane five times. Dodecacarbonyltetrarhodium (1.46g, 1.96 mmol) is obtained by evaporation of the hexane on a rotary evaporator (78% yield). IR (in hexane) 2072, 2070, 2043, and 1886cm . ... 

To a hot ethanol solution (350 ml) of triphenylphosphine (recrystallized from ethanol prior to use, 12 g, 46 mmol) is added a hot ethanol solution (70 ml) of rhodium trichloride trihydrate (2.0 g, 7.6 mmol). The solution is refluxed for 30 min, and red crystals are filtered from the hot solution. The crystals are washed with ether and dried under vacuum. Yield 6.3 g (86 %). The compound is soluble in benzene, chloroform, and dichloromethane. 

To a solution of triphenylphosphine (2.64 g, 10 mmol) in boiling and vigorously stirred ethanol (100 ml) is added a solution of rhodium trichloride trihydrate (0.26 g, 0.99 mmol) in ethanol (20 ml). After 15 s. aqueous formaldehyde (10 ml, 40% w/v) and then a solution of potassium hydroxide (0.8 g) in hot ethanol (20 ml) are added quickly to the reaction mixture. The mixture is refluxed for 10 min, and then cooled to room temperature. The yellow crystals are filtered, washed with ethanol, water, ethanol, and hexane, then dried under vacuum. Yield 0.85 g (94 Yo). 

Rhodium trichloride trihydrate (10 g, 38 mmol) is dissolved in hot water (15 ml), and the solution is added to ethanol (250 ml). The mixture is degassed with an aspirator and filled with 1 atm of ethylene. The reaction mixture is vigorously stirred at room... 

Rhodium trichloride trihydrate (1.0 g, 3.8 mmol) and 1,5-cyclooctadiene (2 ml, ca. 16 mmol) are added to ethanol (30 ml), and the mixture is stirred and refluxed for 3 h. After the mixture is cooled to room temperature, the orange solid is filtered, washed with ethanol, dried, and recrystallized from acetic acid. The crystals are dried under vacuum. Yield 0.56 g (60 %). The crystals are stable under air. Soluble in dichloromethane, chloroform, acetic acid, and acetone, slightly soluble in ether, methanol, ethanol, and benzene, and insoluble in water. 

No alternative preparative method for either ethylene complex has been reported. A synthesis of dichlorotetracarbonyldirhodium from rhodium trichloride trihydrate and carbon monoxide was described in Inorganic Syntheses.3 However, it is convenient to convert [Rh2(C2H4)4Cl2] to [Rh2(CO)4Cl2], even though the over-all yield (60%) of the carbonyl produced in this way from rhodium trichloride trihydrate is less than through direct carbonyla-tion (96 %).3... 

Migration of double bonds. Rhodium trichloride trihydrate is useful for certain exocyclic-endocyclic migrations of a double bond that are usually difficult to achieve. Some examples are formulated. The isomerization of ergosterol is interesting in that it yields a previously unknown coprostatrienol together with crgosterols Bi and B2. 

Isomerization of o>-alkenyl-substituted ( clohexane-l,3-dione enol derivatives using rhodium trichloride trihydrate provides a convenient entry to a variety of resorcinol derivatives. ... 

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