29 results about "Rhodium salt" patented technology

The invention discloses an electrolytic solution of a platinum-rhodium alloy, a preparation method and a preparation method of a plating layer of the platinum-rhodium alloy, and belongs to the technical field of precise electroplating. The electrolytic solution comprises a platinum salt, a rhodium salt, a first additive, a second additive, a first complexing agent, a second complexing agent, a first stabilizer and a second stabilizer, the first additive is a sulfamic acid compound containing 3-4 hydroxyalkyl groups, the second additive is sulfamic acid salt containing 3-4 hydroxyalkyl groups, and the first complexing agent and the second complexing agent are a platinum salt and a rhodium salt. The first complexing agent is a mixture of dicarboxylic acid and dicarboxylic acid containing amino or hydroxyl, the second complexing agent is a salt corresponding to the dicarboxylic acid, and the first stabilizer is a mixture of alkyl sulfonic acid and alkyl sulfonate. Through the synergistic effect of the additive, the complexing agent and the stabilizer, the additive, the complexing agent and the stabilizer form a five-membered to seven-membered heterocyclic coupling structure with platinum ions and rhodium ions, and the stability of the electrolytic solution is remarkably improved. And the obtained platinum-rhodium alloy coating is compact and uniform, and has excellent nitric acid steam and mixed gas corrosion resistance.

The invention belongs to the technical field of resource recycling and precious metal smelting, and relates to a method for recycling high-purity rhodium from rhodium-containing tailings. The method comprises the following steps: dissolving palladium refining hydrolysis residues by using aqua regia, sequentially carrying out rhodium precipitation pretreatment and rhodium precipitation operation to obtain rhodium precipitation rhodium salt, calcining the rhodium precipitation rhodium salt to obtain a calcined sample, and carrying out hydrogen reduction on the calcined sample; wherein the rhodium precipitation pretreatment process comprises the following steps: diluting a solution dissolved by aqua regia with water and hydrochloric acid, and then adding sodium chlorate for oxidation; the rhodium precipitation operation comprises the following steps: adding the rhodium precipitation reagent, and precipitating at 80-90 DEG C; the rhodium precipitation reagent is prepared from an organic matter, water and hydrochloric acid, wherein the organic matter is diethylenetriamine or triethanolamine. According to the method provided by the invention, high-purity rhodium can be collected from the palladium refining hydrolysis slag, the operation is simple and convenient, the impurity removal effect is good, and rhodium powder with qualified grade can be cast.

The invention discloses a method for preparing a chiral benzhydrol compound through asymmetric hydrogenation of o-amido benzophenone under catalysis of rhodium. The chiral rhodium catalyst is generated in situ from a metal rhodium salt and a chiral phosphine-phosphoramidite ligand in various solvents. Compared with other methods for synthesizing chiral benzhydrol, the method has the characteristics of cheap catalyst, easiness in preparation of chiral ligand, mild reaction conditions, simplicity and convenience in operation, high yield, high enantioselectivity and the like, and can be applied to large-scale preparation of chiral benzhydrol compounds. The method is also suitable for efficient preparation of the rice plant growth regulation inhibitor (S)-Inabenide, the yield can reach 92%, the enantioselectivity can reach 96%, and the method has good industrial application prospects.

The invention relates to the technical field of organic medicines, and discloses a ring-opening hydroformylation reaction of benzylidene cyclopropane with formic acid as a carbonyl source. The ring-opening hydroformylation reaction of benzylidene cyclopropane comprises the following steps: under the protection of inert gas, proportionally adding benzylidene cyclopropane, formic acid, a metal rhodium salt, a ligand and acetic anhydride into an organic solvent, reacting under mild conditions, preparing gamma and delta unsaturated aldehyde compounds as shown in the following formula after the reaction, and separating a target product after the reaction is completed. According to the method, formic acid is used as a carbonyl source, the method has the advantages of being simple and novel, and a series of gamma and delta unsaturated aldehyde compounds and derivatives thereof can be synthesized with extremely high efficiency.

The invention discloses a catalyst as well as a preparation method and application thereof, tungsten trioxide nanorods and powdered sulfur are subjected to vulcanization reaction to generate tungsten disulfide, and tungsten disulfide is subjected to plasma etching to obtain a catalyst intermediate; dispersing the catalyst intermediate in a rhodium salt solution, separating and drying to obtain the catalyst; or the tungsten trioxide nanorod can be firstly loaded on the conductive carrier and then subjected to the steps of vulcanization, plasma etching and rhodium loading, and the catalytic material is obtained; the catalyst and the catalytic material provided by the invention have low cost and high hydrogen evolution catalytic efficiency, especially show good catalytic activity and stability under acidic and alkaline conditions, and are expected to realize practical application in the field of hydrogen production by electrolysis of water.

The invention relates to a synthetic method of optically pure (2R, 3R)-dihydroquercetin, which comprises the following steps of: a, reacting m-dimethoxybenzene with ethyl oxalyl chloride under the protection of inert gas and catalysis of Lewis acid to obtain a compound V; b, under the catalysis of divalent cobalt salt, selectively activating the ortho-position C-H bond of the compound V, and reacting with 3, 4-dimethoxybenzyl alcohol to obtain a compound IV; c, carrying out intramolecular cyclization on the compound IV under the alkaline condition of inert gas protection to obtain a compound III; d, under protection of inert gas and catalysis of a rhodium complex formed by monovalent rhodium salt and a chiral phosphine ligand in situ, hydrogenation reduction of double bonds is correspondingly and selectively realized by the compound III, and a compound II is obtained; e, under the catalysis of sodium bromide or sodium iodide, the compound II reacts with aluminum trichloride for demethylation, and optically pure (2R, 3R)-dihydroquercetin is obtained.The synthetic raw materials are low in price and easy to obtain, operation is easy, the yield and optical purity are high, and the method is suitable for industrial production.

The invention belongs to the field of material science, and discloses a preparation method and application of a three-dimensional reticular Rh / Ni (OH) 2 nanowire composite material. The preparation method comprises the following steps: 1) adding nickel salt and urea into water in proportion, and carrying out ultrasonic treatment to obtain a uniform clear transparent solution; (2) transferring the clear and transparent solution into a lining of a polytetrafluoroethylene reaction kettle, adding a rhodium salt solution, and stirring to obtain a mixture solution; and (3) putting cleaned foam nickel with a certain size into the mixture solution, sealing in a reaction kettle, carrying out hydrothermal reaction for a period of time, taking out the reacted foam nickel after the reaction is finished, and washing and drying to obtain the Rh / Ni (OH) 2 nanowire mesh composite material. According to the invention, efficient and stable electro-catalysis water decomposition hydrogen production is realized, the problems of poor intrinsic activity of nickel-based hydroxide in the catalytic hydrogen evolution process, low activity in precious metal alkaline electrolyte and poor stability are solved, and efficient electro-catalysis water decomposition hydrogen production is realized.

The invention belongs to the technical field of precious metal hydrometallurgy, and relates to a method for extracting rhodium from a rhodium-rich material, which comprises the following steps: firstly, purifying rhodium-rich material slurrying liquid by using 3-4% of potassium permanganate solution; then carrying out oxidation leaching on the purified rhodium concentrate by using a mixed reagent of nitric acid, hydrochloric acid and hydrogen peroxide, dissolving rhodium in the concentrate by using a strong oxidant, and further improving the oxidation potential of the system; precipitating the rhodium-rich solution by adopting an ethanol solution of polyethyleneimine to realize efficient precipitation of rhodium, and reacting an alcohol amine reagent with rhodium ions to generate stable rhodium salt, so as to achieve the purpose of separating rhodium from other metal impurities; and finally, after the rhodium salt is pulpified, a hydrazine sulfate solution is adopted for reducing the rhodium salt, the rhodium salt is reduced into metal powder through the strong reducibility of hydrazine sulfate, the nucleation growth speed of rhodium crystals can be increased by controlling the adding speed of a reducing agent, and therefore the uniformity of rhodium powder produced in the reduction process is guaranteed.

The invention belongs to the technical field of organic synthesis, and discloses a synthesis method and application of propylthio-o-phenylenediamine. The invention provides a method for hydrogenation reduction of propylthio-o-nitroaniline into propylthio-o-phenylenediamine in the presence of a catalyst composed of a water-soluble sulfonated phosphine ligand and rhodium salt. Phase-transfer catalysis is used for selective reduction of o-nitroaniline, a water-organic two-phase catalysis system is prepared from a water-soluble sulfonated phosphine ligand and rhodium salt, a catalyst is dissolved in a water phase in the reaction system, a product is dissolved in an organic phase in the reaction system, after the reaction is finished, a water layer containing the catalyst can be recycled, an organic layer is used for separating the product, and the yield of o-nitroaniline is improved. The problem that a catalyst and a product are difficult to separate in a conventional homogeneous system is solved. The synthesis method has the advantages of mild reaction conditions, environmental protection, high yield and purity, relatively low cost and the like. The synthesis method of the propylthio-o-phenylenediamine provided by the invention can be applied to preparation of albendazole and intermediates thereof.

The application belongs to the field of organic chemical medicine, and relates to a synthesis method of N-alkylated pyridine-2-ketone derivatives. The application takes a sulfuryl hydrazone derivative and a pyridine-2-ketone derivative as raw materials, takes a rhodium salt as a catalyst, takes a base as an additive, further adds a proper solvent, seals argon gas reaction, reacts for a certain time at a certain temperature, removes the solvent by reducing pressure after the reaction is finished, and separates the target product through silica gel column chromatography or recrystallization. The synthesis of N-alkylated pyridine-2-ketone derivatives is realized. The method has the following advantages: the raw material is easy to obtain, the stable sulfuryl hydrazone derivative is used as a carbene precursor, and the method is safer; the substrate has wide adaptability, the reaction operation is simple, the reaction efficiency is high, the method is more in line with the requirements of green chemistry, and the derivative product has certain enantioselectivity.

The present application relates to carbon supported rhodium-based ordered intermetallic compound and preparation and application as catalyst, and belongs to the technical field of liquid fuel cell. The preparation method is that carbon carrier is dispersed in a solution of rhodium salt and non-noble metal salt, or the carbon carrier is dispersed in a solution of rhodium salt, other platinum group metal salt and non-noble metal salt, and the metal salt is loaded on the carbon carrier; the dried sample is ground and subjected to two-step heat treatment at low temperature and high temperature under a reducing atmosphere to obtain carbon supported rhodium intermetallic compound. The rhodium intermetallic compound electrocatalyst reduces the overpotential of formic acid oxidation reaction, and improves the catalytic activity, which is significantly superior to the catalytic performance of single metal rhodium, and the catalyst synthesis method is simple and feasible, and is suitable for mass production.

The present invention belongs to the field of organic chemical medicine, and relates to a method for synthesizing 3-tetrasubstituted indolin-2-one compounds by one-pot method. The present invention uses aniline derivatives, 3-diazoindolinone derivatives, and allyl carbonate derivatives as raw materials, rhodium salts, palladium salts, and phosphine ligands as catalysts, and then adds an appropriate amount of solvent, seals and fills with argon gas to react, stirs and reacts for a period of time near room temperature, and after the reaction is completed, the solvent is evaporated under reduced pressure, and the product is separated by silica gel column chromatography or recrystallization to obtain a target product; a three-component one-pot method is achieved to synthesize 3-tetrasubstituted indolin-2-one compounds. The advantages of this method are: easy to obtain raw materials, wide substrate adaptability, mild reaction conditions, simple operation, high efficiency, good atom economy, and more in line with the requirements of green chemistry.

The invention relates to the technical field of fluoride catalysts, and particularly discloses a fluoride catalyst for catalyzing CFC-113a to synthesize CFC-1316mxx and a preparation method of the fluoride catalyst. The fluoride catalyst is prepared from a catalyst precursor, and the catalyst precursor comprises a transition metal salt and a fluoride carrier MFx, wherein the transition metal salt is selected from any one or more of ruthenium salt, rhodium salt, palladium salt, nickel salt and copper salt; the fluoride carrier MFx is selected from any one or more of sodium fluoride, potassium fluoride, magnesium fluoride, calcium fluoride, strontium fluoride, barium fluoride and aluminum fluoride. When the fluoride-based catalyst is used for catalyzing CFC-113a to synthesize CFC-1316mxx through hydrogenation coupling, the CFC-1316mxx selectivity and the CFC-113a conversion rate are remarkably high, and finally, the yield of the target product CFC-1316mxx reaches up to 91.98%.

This invention discloses a multicolor fluorine magnetic resonance imaging probe based on a metal-organic cage. First, a rhodium-based metal-organic cage is formed by the self-assembly of a fluorinated isophthalic acid ligand and a rhodium salt, covalently introducing the first characteristic fluorine signal. Then, leveraging the coordination ability of the rhodium nodes in the rhodium-based metal-organic cage, it coordinates with a fluorinated pyridine derivative, introducing a second characteristic fluorine signal. This results in a multicolor probe containing both fluorine signals within the metal-organic cage, ensuring that all signals exhibit completely consistent pharmacokinetic behavior in vivo. This achieves true multi-channel synchronous imaging, solving the fundamental problem of spatiotemporal asynchrony of mixed probe signals. The probe system of this invention features precise structure, strong design flexibility, high imaging sensitivity, and multicolor imaging capabilities, providing a new solution for existing fluorine probes with single-channel imaging or complex structures. It also provides a new tool for in vivo multi-target biological imaging and dynamic monitoring.

The invention relates to the technical field of asymmetric hydrogenation, and particularly discloses a preparation method of a nebivolol intermediate, the nebivolol intermediate is prepared by adopting asymmetric hydrogenation reaction, the method has remarkable technical advantages, extremely high catalytic activity is realized by selecting a catalytic system composed of a specific chiral phosphine ligand and rhodium salt, and the method is suitable for industrial production. According to the present invention, the molar ratio (S / C) of the substrate to the catalyst is as high as 30,000, the production cost is significantly reduced, the process has characteristics of excellent chiral selectivity and excellent reaction efficiency, the e.e value of the product can achieve more than 99%, the yield is excellent, the yield loss caused by the traditional resolution process is effectively avoided, and the method has characteristics of good compatibility with a variety of organic solvents, and can be used for industrial production. By adding the alkaline auxiliary agent, the reaction effect can be further improved, the process is stable, and the industrial application value is relatively high.

The present invention relates to a plating solution for forming a black rhodium plating film. A black rhodium plating solution according to the present invention includes: a rhodium salt that has a rhodium metal concentration of 1 g / L to 20 g / L inclusive; 10 mL / L to 100 mL / L inclusive of sulfuric acid; 2 mM to 100 mM inclusive of a phosphonic acid derivative or a salt thereof; and a magnesium salt that has a magnesium metal concentration of 0.1 g / L to 10 g / L inclusive. According to the present invention, the phosphonic acid derivative or the salt thereof acts as a blackening agent for a rhodium plating film. This blackening agent makes it possible to obtain the black rhodium plating film that has little change in appearance even after film formation.

The present invention discloses a diphenylamine-linked chiral bis(oxazoline) ligand without C2-symmetry of formula 3 and its synthesis method and application in an asymmetric catalytic reaction, wherein C2-symmetry is lost by introducing different groups into the diphenylamine backbone to realize precise control of “electronic effect” of the ligand backbone. An anthranilic acid derivative and an orthochlorobenzoic acid derivative are used as starting materials to prepare a compound of formula 1, and then the compound of formula 1 is reacted with a chiral amino alcohol compound to prepare a β-bishydroxy amide compound of formula 2, and the compound of formula 2 is further subjected to condensation to obtain the diphenylamine-linked chiral bis(oxazoline) ligand without C2-symmetry of formula 3. The present invention also provides an application of a catalyst formed by coordination of the diphenylamine-linked chiral bis(oxazoline) ligand without C2-symmetry with copper salt, zinc salt, nickel salt, iron salt or rhodium salt, in an asymmetric catalytic reaction.

The invention discloses an electroplating solution and a manufacturing method of a rhodium alloy plating layer. Each liter of the electroplating solution comprises the following components: rhodium salt, a pH regulator, alloy element salt, a phosphorus-containing additive, a low stress agent, a wetting agent and the balance of water. Wherein the alloy element salt comprises iridium sulfate and / or indium sulfate. According to the electroplating liquid, alloy elements are introduced, meanwhile, the additives are added, and electroplating current parameters are changed, so that a plating layer has low stress and high toughness, and meanwhile, the specific advantage of high hardness of a rhodium plating layer is reserved.

This invention discloses a methanol-to-ethanol catalyst, its preparation method, and its applications, comprising: a composition satisfying the chemical formula: Cu a Zn b Rh g Co l Fe μ Ca h Al ρ O c / C 100 The atomic ratios of the elements in the formula are: a = 5.5–14, b = 0.5–1, g = (4–5) × 10. ‑5 The parameters are: l = 0.2–0.3, μ = 0.2–0.3, h = 0.002–0.003, ρ = 0.002–0.003, and c is the number of oxygen atoms required to satisfy the valence of each element. The preparation process involves mixing the prepared asphalt-based activated carbon powder and amorphous hydroxyl iron oxide powder with basic zinc carbonate powder, then impregnating them with an equal volume of a mixed solution of copper, cobalt, and rhodium salts. After drying, the mixture is kneaded and shaped with a high-alumina cement molding agent. In the continuous reaction process of methanol conversion to ethanol, this catalyst exhibits good diffusion performance, conversion activity, product selectivity, and high operational stability.

This invention relates to an optically pure (2) R ,3 R The synthesis method of dihydroquercetin includes the following steps: a) under inert gas protection and Lewis acid catalysis, m-phenylenedimethyl ether and oxaloyl chloride monoethyl ester react to give compound V; b) under divalent cobalt salt catalysis, the C-H bond at the ortho position of compound V is selectively activated, and then reacted with 3,4-dimethoxybenzyl alcohol to give compound IV; c) under alkaline conditions under inert gas protection, compound IV undergoes intramolecular cyclization to give compound III; d) under inert gas protection and catalysis of a rhodium complex formed in situ by a monovalent rhodium salt and a chiral phosphine ligand, compound III selectively undergoes hydrogenation reduction of the double bond to give compound II; e) under sodium bromide or sodium iodide catalysis, compound II reacts with aluminum trichloride to demethylate, and then yields optically pure (2-)-dihydroquercetin. R ,3 R The present invention synthesizes dihydroquercetin using inexpensive and readily available raw materials, with simple operation, high yield and optical purity, making it suitable for industrial production.

The invention belongs to the field of asymmetric catalytic synthesis, and specifically discloses a method for synthesizing N-alkylated indole derivatives with high stereoselectivity. The invention adopts a method for synthesizing N-alkylated indole derivatives with high enantioselectivity using a racemic rhodium salt catalyst combined with chiral phosphoric acid to synergistically catalyze 3-isopropyl indole derivatives and aryl or alkyl diazo esters, and obtains non-natural amino acid derivatives with high stereoselectivity. The method of the invention has the advantages of simple reaction operation, simple and easy-to-obtain raw materials, mild reaction conditions, wide substrate application range, high efficiency and good enantioselectivity.

The invention belongs to the technical field of electroplating rhodium plating solutions, and particularly relates to a rhodium-based composite plating solution for a surface coating of an MEMS probe and an electroplating method of the rhodium-based composite plating solution. The composite plating solution comprises rhodium salt, an acid stabilizer, an additive, a dispersing agent and nanoparticles suspended in the composite plating solution. According to the composite plating solution, special particle components are introduced, second-phase particles are evenly embedded into a plating layer while rhodium is deposited, the problems that when the rhodium plating layer, especially the rhodium plating layer with the thick tip of an MEMS probe, is large in brittleness and prone to breakage are effectively solved, and due to the fact that the nano powder has the characteristics of self-lubricating performance, high hardness and the like, the service life of the nano powder is prolonged. And the prepared rhodium composite coating also has excellent performances such as higher hardness, corrosion resistance, wear resistance and the like.

The present invention discloses a catalyst, a preparation method thereof and an application thereof. Tungsten trioxide nanorods are subjected to a sulfidation reaction with sulfur powder to generate tungsten disulfide, and the tungsten disulfide is subjected to plasma etching to obtain a catalyst intermediate; the catalyst intermediate is dispersed in a rhodium salt solution, separated and dried to obtain a catalyst; alternatively, the tungsten trioxide nanorods can be first loaded on a conductive carrier and then subjected to the steps of sulfidation, plasma etching and rhodium loading to obtain a catalytic material; the catalyst and catalytic material of the present invention can have both low cost and high hydrogen evolution catalytic efficiency, and in particular, exhibit good catalytic activity and stability under both acidic and alkaline conditions, and are expected to be practically applied in the field of electrolytic water hydrogen production.

The invention discloses a platinum-rhodium alloy chemical plating solution, a preparation method and a preparation method of a platinum-rhodium alloy film, and belongs to the technical field of chemical plating. The chemical plating solution comprises platinum salt, rhodium salt, a reducing agent, a first alcohol amine complexing agent, a second polymeric alcohol amine complexing agent, a phosphate stabilizer and an additive. According to the invention, a compound of alkylol amine and polymeric alkylol amine is selected as a complexing agent, carbohydrazide is taken as a reducing agent, the proper reduction capability of carbohydrazide ensures the moderate deposition rate, and the problem of rough coating caused by too fast reduction or low deposition efficiency caused by too slow reduction is avoided. The compounding of the phosphate stabilizer effectively inhibits the spontaneous decomposition of the plating solution, prolongs the service life of the plating solution, and ensures the stability of the process. According to the platinum-rhodium alloy plating solution, the sulfonic acid inner salt containing ammonium ions or amino is used as an additive and can be adsorbed on the surface of an electrode, the deposition behavior of metal atoms is regulated and controlled, and all the components cooperate with one another to jointly guarantee that a high-quality platinum-rhodium alloy plating layer can be obtained within a limited concentration range.

The invention belongs to the field of organic chemistry, and particularly relates to a synthesis method of a zalvizepam chiral intermediate, a compound V is used as a starting raw material and is subjected to asymmetric hydrogenation in a solvent through a chiral catalyst to obtain a compound VI, the chiral catalyst is a chiral phosphine ligand of rhodium salt, and the ligand is one of Duphos, Tangphos, Zhangphos, Binapine, Duphos, (R)-BINAP, (R)-SEGPHOS, MeO-POP and Manyphos. A group of better reaction systems is obtained by screening the chiral rhodium catalyst, the asymmetric hydrogenation process can be efficiently realized, the zalvizepam intermediate as shown in the formula II can be efficiently and selectively synthesized, and the method has a better industrial application prospect.

The application discloses a modified Rh crystal catalyst and a preparation method and application thereof. The catalyst comprises a carrier Rh icosahedral twin crystal and Ru monatomic atoms loaded on the Rh icosahedral twin crystal, wherein Rh is zero-valence, and Ru exists in a divalent form; the preparation method comprises the following steps: (1) polyvinylpyrrolidone is dissolved in trioxa tetraethylene glycol solvent, preheating is carried out under stirring at 250-270 DEG C, then rhodium salt is slowly added, and a black Rh icosahedral twin crystal is obtained through reaction; (2) the Rh icosahedral twin crystal powder prepared in the step (1) is dispersed in an aqueous solvent with ruthenium salt, is mixed uniformly, active carbon is added, is dispersed uniformly, high-temperature calcination is carried out under a nitrogen atmosphere, and the catalyst is obtained through cooling. The catalyst takes the icosahedral rhodium crystal as a carrier, loads monatomic ruthenium on the icosahedral twin crystal, and through improvement of the rhodium crystal structure and synergistic effect of the ruthenium, the oxidation electrocatalytic performance and stability of the catalyst to methanol are improved.

The invention provides an alloy catalyst for catalyzing synthesis gas to directly prepare ethanol and a preparation method of the alloy catalyst, and relates to the technical field of catalysts. The preparation method comprises the following steps: S1, uniformly mixing a rhodium salt solution and an M metal salt solution in a solvent to obtain a mixed solution; s2, adding a carrier into the mixed solution obtained in the S1, and uniformly stirring to obtain a paste containing an alloy; and S3, the paste obtained in the S2 is sequentially subjected to aging, heating drying, cooling and calcination, and the alloy catalyst is obtained. The alloy catalyst for catalyzing synthesis gas to directly prepare ethanol, which is prepared by the preparation method, comprises an active component and a carrier, wherein the active component is loaded on the carrier in the form of an Rh-M alloy cluster structure. The preparation method provided by the invention is simple in step and easy in condition control, the prepared alloy catalyst has a specific alloy cluster structure and good stability, and is used for directly preparing ethanol by catalyzing synthesis gas, and the CO conversion rate, ethanol selectivity and ethanol yield are all remarkably improved.

The present invention relates to a plating solution for forming a black rhodium plating film. The black rhodium plating solution according to the present invention comprises a rhodium salt with a metallic rhodium concentration of 1 g / L or more and 20 g / L or less, sulfuric acid with a concentration of 10 mL / L or more and 100 mL / L or less, a phosphonic acid derivative or its salt with a concentration of 2 mM or more and 100 mM or less, and a magnesium salt with a metallic magnesium concentration of 0.1 g / L or more and 10 g / L or less. In the present invention, the phosphonic acid derivative or its salt acts as a blackening agent for the rhodium plating film. By means of this blackening agent, a black rhodium plating film with minimal change in appearance even after formation can be obtained.

The invention discloses a novel diphosphine ligand taking bisphenol A as a skeleton, and a synthesis method and application thereof, and particularly relates to a bisphenol A skeleton (such as a compound as shown in a formula II) obtained by taking substituted phenol as a starting material and carrying out reactions such as acid catalysis and hydroxyl alkylation. Carrying out substitution reaction on the bisphenol A skeleton and disubstituted phosphonium chloride to obtain a diphosphine ligand (a compound as shown in a formula I) taking bisphenol A as the skeleton; the invention also discloses an application of the novel diphosphine ligand taking bisphenol A as the skeleton in olefin hydroformylation reaction after the novel diphosphine ligand taking bisphenol A as the skeleton is matched with active metal, for example, a rhodium complex obtained by complexing the novel diphosphine ligand taking bisphenol A as the skeleton with rhodium salt shows excellent activity, selectivity and stability in hydroformylation reaction of 1-octene, 1-decene and dicyclopentadiene.