New method for synthesizing rhodium caprylate (II)

Abstract

The invention discloses a new method for synthesizing rhodium caprylate (II), which is characterized by comprising the following steps: dissolving a certain amount of rhodium chloride in water; adding 120 to 300 theoretical percent of octylic acid into the water, and adjusting the pH valve of the obtained solution to between 4.5 and 6.5 by using alkali; heating the solution to the temperature of between 90 DEG C and 100 DEG C, reacting for 3 to 5 hours, and filtering the solution when the solution is hot; and fully washing by using water, and drying to obtain a green rhodium caprylate (II) product. The method for synthesizing the rhodium caprylate (II) has the advantages of high reaction speed, high yield (over 95 percent), high product purity (over 99 percent), small environmental pollution, and suitability for industrial production.

Description

technical field [0001] The invention relates to a method for synthesizing rhodium homogeneous catalyst-rhodium (II) octanoate, which belongs to the field of chemistry and chemical engineering. Background technique [0002] Rhodium(II) octanoate is widely used in the fields of basic chemical industry and pharmaceutical chemical industry because of its remarkable catalytic activity for cyclopropanation reaction and olefin hydroformylation reaction, and is an important rhodium homogeneous catalyst. Rhodium(II) octanoate was first reported in 1986 by Giround-Godguin, A.M. et al. However, they only mention the synthesis by ligand exchange method, and the specific synthesis method is not reported in detail, and its characterization method is also limited to elemental analysis (Giround-Godguin AM, Marchon JC, Daniel G, AntoineS, Discotic Mesophases of Dirhodlum Tetracarboxylates, J Phys Chem, 1986, 90, 5502-5503). Subsequently Chisholm, the people such as M.H. have reported in de...

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Problems solved by technology

However, they only mention the synthesis by ligand exchange method, and the specific synthesis method is not reported in detail, and its characterization method is also limited to elemental analysis (Giround-Godguin AM, Marchon JC, Daniel G, AntoineS, Discotic Mesophases of Dirhodlum Tetracarboxylates, J Phys Chem, 1986, 90, 5502-5503)

Subsequently Chisholm, the people such as M.H. have reported in detail and adopt rhodium acetate (II) and octanoic acid to carry out ligand exchange reaction to synthesize rhodium octanoate (II) method, but its reaction process is long, yield is low, is not suitable for industrial production (Chisholm MH, Christou G, Folting K, Huffman JC, James CA, Samuels JA, Wesemann JL, and. Woodruff WH, Solution Studies of Ru 2 (O 2 CR) 4 n+ Complexes (n=0, 1; O 2 CR=Octanoate, Crotonate, Dimethylacrylate, Benzoate, p-Toluate) and Solid-State Structures of Ru 2 (O 2 C-p-tolyl) 4 (THF) 2 ,[Ru 2 (O 2 C-p-tolyl) 4 (THF) 2 ] + [BF4] - , and Ru 2 (O 2 C-p-tolyl) 4 (CH 3 EN) 2 : Investigations of the Axiai Ligation of the Ru 2 Core, Inorg. Chem. 1996, 35, 3643-3658)

People such as Qin Yongnian use a Soxhlet extractor to increase the reaction yield of rhodium (II) acetate and octanoic acid to more than 98% on the basis of the ligand exchange method, but from the raw material rhodium trichloride, the total yield is only 70% Left and right, and its reaction also has the disadvantages of many reaction steps, long reaction time, complicated operation, etc.

In addition, the ligand exchange method involves a separation problem of octanoic acid and rhodium (II) octanoate. Due to the high solubility of rhodium (II) octanoate in octanoic acid and the high boiling point of octanoic acid (237 ° C), the separation is very difficult. Difficult, usually requires the use of toxic reagents such as toluene and chlorobenzene, which is not conducive to environmental protection