Introduction of per(fluoroorganosilyl) peripheries into carbosilane dendrimers and related core-functionalized monodendrons gives rise to anomalous hydrodynamic and viscosimetric behavior

Abstract

Platinum-catalyzed hydrosilylation of allyl-terminated carbosilane monodendrons using the silanes SiHMe₂[(CH₂)_nR_f] (1a, n = 2, R_f = n-C₆F₁₃; 1b, n = 3, R_f = −C₆F₅) yields fluorous, liquid analogues to [G-3], BrC₆H₄(CH₂)₃SiMe[(CH₂ )₃SiMe[(CH₂)₃SiMe[(CH₂) ₃SiMe₂(CH₂)_nR_f] ₂]₂]₂ (7a, n = 2, R_f = n-C₆F₁₃- ; 7b, n = 3, R_f = −C₆F₅), intrinsic viscosities [η] for which are unusually low, resulting in calculated hydrodynamic radii/Å (ca. 6.3, [G-1]; 8.3, [G-2]; 11.5, [G-3]) that imply unusually compact structures.