pi complexes of fluorous alkynes, cyclobutadienes, and benzenes: Syntheses and phase properties of cobalt and chromium tricarbonyl adducts Academic Article uri icon

abstract

  • Reactions of Cr(CO)6 and fluorous benzenes C6H 6-x((CH2)3Rf8)x (x a, 1; b, 2 (1,2); c, 2 (1,3); d, 2 (1,4); e, 3 (1,3,5); Rf8 (CF2)7CF3; dibutyl ether, 140C) give the complexes (6-C6H6-x((CH 2)3Rf8)x)-Cr(CO)3 (1a-e; 92-42%); p-Rf8(CH2)3C6H 4CH(S(CH2)3Rf8) (CH 2)2Rf8 affords an analogous adduct (1f; 47%). The CF3C6F11/toluene partition coefficients of 1a-f increase with the number of ponytails (three, 99:1 to 97:3; two, 91:9; one, 49:51); the fluorophilicities are only slightly less than a-f. The IR CO values show any residual inductive effect of the perfluoroalkyl groups at chromium to be slight. The reaction of LiCCSi(CH3)3 and Rf8(CH 2)3I gives the fluorous alkyne Rf8(CH 2)3CCSi(CH3)3 (2; 63%). Addition of wet n-Bu4N+ F- affords R f8(CH2)3CCH (71%), which upon treatment with t-BuLi and Rf8(CH2)3I yields R f8(CH2)3CC(CH2) 3Rf8 (4; 58%). The reaction of 2 and Co 2(CO)8 gives the alkyne complex Co2(CO) 6(2--Rf8(CH2) 3CCSi(CH3)3) (88%). Reactions of 2 or 4 with (5-C5H5)Co(CO)2 (2:1, decane, 150-160C) give the cyclobutadiene complexes (5-C 5H5)Co{4-C4[Z] 2[(CH2)3Rf8]2} (Z = Si(CH3)3, 6, 70%; (CH2)3R f8, 7, 32%). The CF3C6F11/toluene partition coefficients show 6 and 7 to be more fluorophilic than their precursors 2 and 4, despite the added (5-C5H 5)Co groups. 2006 American Chemical Society.

published proceedings

  • ORGANOMETALLICS

author list (cited authors)

  • Dinh, L. V., Consorti, C. S., Emnet, C., & Gladysz, J. A.

citation count

  • 4

complete list of authors

  • Dinh, LV||Consorti, CS||Emnet, C||Gladysz, JA

publication date

  • February 2006