Isopentane carbonylation

Carbonyl and thiocarbonyl complexes of Mes2Si have been observed in a remarkable series of experiments by Ando and coworkers144. Photolysis of Mes2Si(SiMe3)2 was carried out at 77 K in a soft (3-MP/isopentane) matrix in the presence of tetramethyl-2-indanone or its sulfur analog. The free silylene was formed initially but it slowly reacted with the carbonyl (or thiocarbonyl) compound to give the complex, which can be formulated as a silacarbonyl ylide (Scheme 8). Further photolysis converted these ylide complexes to the silaoxirane or silathiirane, reversibly. 

R. K. Sheline et al. 137,441,442) presented IR spectroscopic evidence for Cr(CO)5, Mo(CO)5 and W(CO)5 by low temperature irradiation of the corresponding carbonyls in isopentane-methylcyclohexane glasses. The IR data obtained are consistent with Cm symmetry for all three (square pyramidal) pentacarbonyls. On warming up carefully the glass with Mo(CO)5 a transformation to a trigonal bipyramidal species with Dzu symmetry occurs. 

For nonpolar fluids [32, 33] (methane, ethane, propane, n-butane, w-pentane, n-hexane, n-heptane, n-octane, argon, oxygen, nitrogen, ethylene, isobutane, cyclohexane, sulfur hexafluoride, carbon monoxide, carbonyl sulfide, n-decane, hydrogen sulfide, isopentane, neopentane, isohexane, krypton, w-nonane, toluene. 

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