Synthesis and Covalent Grafting of Tripod‐Shaped Oligo(p‐phenylene)s End‐Capped with Azide Groups

Abstract

Here we report the synthesis and characterization of several tripod-shaped oligo(p-phenylene)s molecules with legs composed of five and three phenylene units, compounds 1 and 2,r espectively.I nt heses tructures, each leg is end-capped with an azide group andt he terminal functional arm contains an acetylene or bromine group. The presented synthesis has as the key step aP d-catalyzedS uzukic rosscoupling reaction. In particular,t he iodine derivative from the silicon core molecule reacts with the appropriate oligo(p-phenylene) boron derivative, thus generating the final tripod-shaped structure. The azide end-capped leg is specifically designed for its covalentincorporation on alkynyl terminated silicon surfaces in an easy and reproducible way. As ap reliminarys tudy,w ep resent the nanostructuration of tripod 2a on alkynyl-functionalized silicon waferst hrough copper-catalyzed alkyne-azide cycloaddition (CuAAC) click reaction.

Tripodal penta( p -phenylene) for the biofunctionalization of alkynyl-modified silicon surfaces

“…27 Despite this, and since we have previously obtained good results for the attachment of a small tripod (three phenylene units) on alkynyl modified silicon surfaces, in this work we initially prepared the penta(p-phenylene) modified surfaces by following the same procedure. 20 The clickable silicon surfaces were prepared by photo-activated hydrosilylation reaction of the alkene derivative 3 onto H-Si(111) substrates (Surface A in Scheme 1). 28 Then, tripod 1-modified silicon surfaces were prepared by CuAAC reaction onto the previously prepared surfaces in presence of 1, a copper source and a base (Surface B in Scheme 1).…”

“…28 Tripod 1 was synthesized by Suzuki-coupling of corresponding boron esters, according to the published procedures. 20,25 Tetrahydrofuran (THF) was dried and distilled from sodium benzophenone under an argon atmosphere, and dichloromethane was dried and distilled from CaH2 under an argon atmosphere. Millipore water was used when needed.…”

“…19 In a preliminary work, we covalently attached tripodshaped tri(p-phenylene)s on alkynyl-terminated silicon wafers in a highly ordered distribution by using CuAAC conditions for potential application in the specific adsorption of proteins. 20 This type of protein immobilization at surfaces is of great importance in a number of applications, including surface-based bioassays, 21 biosensors, 22 clinical diagnosis and biomedical devices such as implants. 23 In this case, the modified-surfaces must be fabricated to present functional moieties that can specifically interact with proteins while avoiding interaction with all other proteins.…”

Nanoscale Biocompatible Structures Generated from Fluorinated Tripodal Phenylenes on Gold Nanoprisms

“…Synthesis of tripodal compound 1 . Under argon atmosphere, compound 11 [58a] (422 mg, 0.53 mmol), compound 3 (780 mg, 1.60 mmol), Pd(PPh 3 ) 4 (368 mg, 0.318 mmol) and AgCO 3 (1.0 g, 4.24 mmol) were dissolved in dry THF. The mixture was stirred under argon atmosphere at 20 °C for 12 h. After this period, the reaction mixture was filtered through celite, washed with several portions of CH 2 Cl 2 and the solvent was removed under vacuum.…”

Preparation, characterization, and protein-resistance of films derived from a series of α-oligo(ethylene glycol)-ω-alkenes on H–Si(111) surfaces

“…58,59 We and others have reported the photo-activated graing of the a-OEG-u-alkenes onto hydrogen-terminated silicon, forming OEG-terminated monolayers that are directly bound to the silicon substrate via Si-C bonds (Scheme 1). 13,40,48,51,[60][61][62][63][64][65][66][67][68][69][70][71][72] We performed this process in a simple apparatus combining a Schlenk tube with a quartz cell at a low vacuum level, 68,69,73,74 using OEG-terminated alkenes C 11 EG n (n ¼ 3, 6, 7 and 9). We found that C 11 EG n with n $ 6 led to lms that reduced the adsorption of brinogen to $3% monolayer aer immersion in brinogen (1 mg mL À1 ) for 1 h and brief washing with water.…”