Julian Feldman

Membrane-supported rhodium hydroformylation catalysts

Abstract Films prepared from THF solutions containing cellulose acetate, [HRh(CO)(PPh3)3] and PPh3 were tested for catalytic activity in the vapor phase hydroformylation of ethylene and propylene: RCH=CH2+CO+H2→RCH2CH2CHO. The reaction proceeded smoothly at 800 ton- and 80 °C. Turnover rates were about 25 mol propanai per mol Rh per h. No loss of PPh3 or Rh from the film was observed even after long periods of reaction. The excess PPh3 seemed to stabilize the catalytic activity of the film but concentrations beyond 10 molar produced no further improvement. The turnover rate with the films was equal to or even slightly higher than that obtained under similar conditions using a homogeneous solution of [HRh(CO)PPh3] in 2-methylmaphthalene solvent. The turnover rate for propylene to C-4 aldehydes was about an order of magnitude smaller than that for ethylene to propanal. Films prepared from poly(phenylsulfone) were also active catalysts. The ratio of n/iso C-4 aldehydes with this support was about 20. In the absence of oxygen the catalyst system retained its activity for more than 13 days but no attempt was made to test for longer lifetimes. The use of polymeric films or membranes as a support for the rhodium catalysis of the hydroformylation reaction thus appears to hold considerable promise.

One-pot synthesis of fac-[Mn(CO)3(PP)Cl] from Mn2(CO)10, [PP] and chlorinated solvents: [PP] = 1,2-bis(diethylphosphino)ethane (depe), 1,2-bis(diphenylphosphino)ethane (dppe) or 1,3-bis(diphenylphosphino)propane (dppp). The X-ray crystal structure of fac-[Mn(CO)3(depe)Cl]

Abstract In a one-pot reaction, the three titled manganese chloride complexes were prepared by refluxing Mn2(CO)10 with (PP) in 2-chloroethanol for two hours. The new compounds were characterized by IR, 1H NMR, mass spectra and microanalyses. The X-ray crystal structure of fac-Mn(CO)3(depe)Cl is also reported.

A NEW ROUTE TO MANGANESE AND RHENIUM CARBONYL TETRAFLUOROBORATE SALTS AND AN IMPROVED PROCEDURE FOR PREPARING THEIR PRECURSOR HYDRIDES

Abstract Tetrafluoroborate salts of substituted Mn and Re carbonyls can be prepared in almost quantitative yield from their corresponding hydrides by the following reaction: where P2 are either the chelating phosphines, 1,2-bis(diphenylphosphino)ethane or 1,3-bis(diphenyi-phosphino)propane, or triphenylphosphine. The hydrides may be prepared from M2(CO)10 in a single reaction by refluxing the decacarbonyl in 1-pentanol in the presence of the desired phosphine.

Determination of methyl tert. butyl ether (MTBE) in gasoline

Abstract A GLC-acid extraction method is described for the determination of MTBE in gasolines. The method consists of a programmed GLC analysis starting at about room temperature conducted before and after extraction with cold 85% phosphoric acid. This treatment results in the preferential solubility of ethers and other oxygenated compounds while minimizing the reaction of olefins and aromatics which may be present in the gasolines. Plotting various known concentrations of MTBE in gasolines against the concentrations determined in the same samples by our methodolgy results in a straight line relationship. The concentration of MTBE in any sample of gasoline may thus be determined using our GLC extraction procedure and the calibration line. The analysis can accomodate a wide choice of standard GLC columns and programs.