Trimethylphosphine

Dibutyl ether (Aldrich, 99%) is dried and freed from dissolved molecular oxygen by distillation under nitrogen from a solution of the solvent and sodium benzophenone ketyl. 

Triphenyl phosphite (Aldrich, 97%) is purified by fractional vacuum distillation (bp 181-183 °C, 1 torr) and stored in the dark under nitrogen. A 2 M solution of CH3MgBr in dibutyl ether may be purchased from Alfa Inorganics, or prepared according to the following procedure. If the CH3MgBr solution is prepared in the laboratory, bromomethane (Air Products) is used without further purification. 

After the addition of bromomethane is complete, the dropping funnel is replaced with a stopper, the ice tub is removed, and the Grignard solution is stirred at room temperature for 4 h (or overnight if this is more convenient). 

The stopper is then replaced with a 500-mL pressure-equalizing dropping 

Product is collected until the still head temperature reaches 110 °C. At this point the heating mantle is removed, the nitrogen flow is increased slightly, and the distillation flask is allowed to cool. When the latter is cool enough to touch, the receiving flask is carefully disconnected under a positive N2 flow, and capped. The warm residue in the distillation flask (which solidifies on 

It has been pointed out that the best yields of trialkylphosphines are obtained from phosphorus(III) chloride and a large excess of the chloride-Grignard reagent reacting at as low a temperature as practicable, down to — 78°. Further, it is known that methylmagnesium chloride can be 

The reaction vessel used in the preparation of methyl-magnesium chloride is a 2-1. round-bottomed flask with a 30-cm.-long 20-mm.-o.d. glass column sealed to its bottom. The flask is fitted with a two-hole rubber stopper which bears 6-mm. glass inlet and outlet tubes for the methyl chloride gas. The inlet tube extends to the bottom of the glass column, and the outlet tube is fitted with a silica gel drying tube to prevent moisture from entering the system. 

Tetraethylene glycol dimethyl ether is the solvent for the preparation. Practical-grade material is purified before use by allowing approximately 2 kg. to remain overnight in contact with about 20 g. of fresh lithium tetrahydroaluminate in a properly vented vessel at 80°. Then it is distilled from lithium tetrahydroaluminate under reduced pressure (b.p. 110° at 0.75 mm.) and kept dry until used. (The checkers note that the solvent can be dried by heating with sodium as an alternate to the somewhat more hazardous tetrahydroaluminate.) 

Iodine-activated magnesium - is used to initiate the reaction of magnesium and methyl chloride. About 0.5 g. of magnesium turnings and 0.1 g. of iodine are placed in a 10-ml. test tube and covered with about 2 ml. of anhydrous ethyl ether. After the reaction has proceeded for about 5 minutes, the excess liquid is decanted, and the test tube is heated carefully with a free flame to a dull redness. The test tube is allowed to cool somewhat. While it is still warm, about 5 ml. of tetraethylene glycol dimethyl ether, previously saturated with methyl chloride, is added. Additional gentle warming may be required if the reaction does not start immediately. 

A total of 20 g. of the complex can be obtained, corresponding to a 3deld of 43% trimethylphosphine based on the original amount of phosphorus (III) chloride used. (The checkers report a yield of 11%.) Trimethylphosphine is obtained by decomposition of the complex through heating. Decomposition becomes observable at an oil bath temperature of 140°, and heating can be continued to 260°. 

In some instances the substitution of methyllithium for a methyl Grignard reagent offers significant advantages in product isolation and product yields. 

Inorganic Syntheses, Volume XVI Edited by Fred Basolo Copyright 1976 by McGraw-Hill, Inc. 

The present availability of this reagent makes it a desirable reactant for the synthesis presented here. 

The usefulness of this preparation is demonstrated by the good yields of product which can be obtained even when the reaction is conducted at room temperature. For example, when mole of PCI3 and 1 mole of CH3Li were 

The stopper is then replaced with a 500-mL pressure-equalizing dropping funnel and the white Grignard suspension is cooled to — 5 °C with a large ice-salt bath. A solution of triphenyl phosphite (300mL, 355.2g, 1.145 mol) and dibutyl ether (300mL) is added dropwise to the Grignard solution, with 

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It is isoelectronic and isostmctural with the aluminum sandwich ion [i (9y y (9-3,3 -Al(3,l,2-AlC2B2H22)2]A shown iu Figure 26a. TThe siUcon is Tj -bonded iu unshpped fashion to the C2B2 faces of two dicarboUide cages. TThis bis-dicarboUide sUicon sandwich also forms adducts of a variety of stmctural types with Lewis bases such as pyridine and trimethylphosphine. 

Triethylphosphine [554-70-1] M 118.2, b 100"/7mm, 127-128"/744mm, (I4 0.812, n D 1.457, pK 8.69 (also available as a l.OM sola in THF). All operations should be carried out in an efficient fume cupboard because it is flammable, toxic and has a foul odour. Purified by fractional distn at atm pressure in a stream of dry N2, as it is oxidised by air to the oxide. In 300% excess of CS2 it forms Et3PCS2 (m 118-120" cryst from MeOH) which decomposes in CCI4 to give Et3PS as a white solid m 94" when recryst from EtOH. [Sorettas and Isbell 7 Org Chem 27 273 1962 J Am Chem Soc S2 5791 I960, pK Henderson and Streuli 7 Am Chem Soc S2 5791 I960, see also trimethylphosphine.] Store in a sealed vial under N2. 

Thiophene reacts with ReH7(PPh3)2 aided by the H-acceptor (3,3-dimethyl-l-butene) to give the thioallyl species 113 (92JA10767). Further reaction of 113 with trimethylphosphine yields organometallic products with a cleaved C—S bond. 

The first ri -transition metal organometallic complexes 272 were made from Li(Mc4C4ESiMe3) (E = Si, Ge) and Cp HfC (98JA8245). Species 272 (E = Si) with trimethylphosphine forms the Hf-PMc3-adduct. 

Complexes of trimethylphosphine (cone angle 118°) [115]. Syntheses are shown in Figure 2.63. The rhodium(III) complexes can be made by the usual routes or by oxidation of rhodium(I) complexes. Note that in contrast with the bulkier PPh3, refluxing RhCl3 with PMe3 does not result in reduction. 

Figure 2.63 Syntheses and interrelationships between rhodium complexes of trimethylphosphine.

Fig. 2. ORTEP view of the cation in bis(trimethylphosphine)(diphenylsilanediyl)(pentame-thylcyclopentadienyl)ruthenium tetraphenylborate x acetonitrile 12 [37]...

Cobalt, dinitratobis(trimethylphosphine oxide)-angular parameters, 1,57 structure, 1, 57... 

Nickel, dibromoethylbis(pyridyl)-solid state reactions, 1, 470 Nickel, dibroinoisopropylbis(pyridyl)-solid state reactions, 1, 470 Nickel, dibromotris(trimethylphosphine)-structure, 1, 45... 

Nickel, methyltetrakis(trimethylphosphine)-tetraphenylborate stereochemistry, 1,44 Nickel, pentacyano-isomerism, 1, 206 structure, 1, 40 Nickel, tetracarbonyl-cxchangc reactions, 1,288 Nickel, tetracyano-, 5,67 Nickel, tetrahalo-, 5, 186 Nickel, tetrakis(dinitrogen)-syn thesis... 

Rhodium, hydridotetrakis(triaryl phosphite)-, 4, 922 Rhodium, hydridotetrakis(triethyl phosphite)-, 4, 921 Rhodium, hydridotetrakis(trifluorophosphine)-, 4, 921 Rhodium, hydridotetrakis(trimethylphosphine)-, 4, 924 Rhodium, hydridotetrakis(triphenylphosphine)-, 4, 921, 922... 

Rhodium, tetrakis(trimethylphosphine)-reactions, 4, 926 Rhodium carboxylates, 4,903 chemotherapy, 4, 903 Rhodium complexes, 4. 901 acetylacetone synthesis, 2, 376 alkylperoxo... 

Calculate (a) the standard enthalpy of vaporization of trimethylphosphine (b) the standard entropy of vaporization of trimethylphosphine (c) the vapor pressure of trimethylphosphine at 15.0°C. 

Trialkylaluminiums Hexacarbonyl molybdenum Copper (II) sulphide Trimethylphosphine... 

Trimethylphosphine and dimethylphenylphosphine form crystalline adducts (61) with chlorodiphenylphosphine. The adducts are in equilibrium with their starting materials in dichloromethane. 

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