Synthesis, characterization and electrochemical behavior of unsymmetric transition metal-terminated biphenyl ethynyl thiols

Synthesis, Electrochemical Behavior, and Self‐Assembly of Metallocene‐Functionalized Thiofluorenes

“…[36] In view of the above notion, we recently reported the synthesis and characterization of metallocene-terminated biphenyl ethynyl thiols Mc-CϵC-C 6 H 4 -C 6 H 4 -SH [8b: Mc = (η 5 -C 5 H 4 )(η 5 -C 5 H 5 )Fe; 9b: Mc = (η 5 -C 5 H 4 )(η 5 -C 5 H 5 )Ru] and their use as molecular constituents for the preparation of homogeneous, conformal, and mixed SAMs on Au substrates. [28,31,37] In these molecules, the electrochemically active Mc moieties are connected to the thiol head-group through a biphenyl-alkynyl unit, which is considered to be a relatively good molecular conductor, a prerequisite for the fast transfer of electrochemical signals to the substrate. [37] As an alternative to the biphenyl-alkynyl unit, a dialkylfluorenyl moiety can be considered, which differs from bi-phenyl by a C[(CH 2 ) n CH 3 ] 2 connectivity in the biphenyl backbone.…”

“…[28,31,37] In these molecules, the electrochemically active Mc moieties are connected to the thiol head-group through a biphenyl-alkynyl unit, which is considered to be a relatively good molecular conductor, a prerequisite for the fast transfer of electrochemical signals to the substrate. [37] As an alternative to the biphenyl-alkynyl unit, a dialkylfluorenyl moiety can be considered, which differs from bi-phenyl by a C[(CH 2 ) n CH 3 ] 2 connectivity in the biphenyl backbone. [37,38] This connectivity fixes the phenylene units relative to each other in a planar conformation, in contrast to biphenyl in which possible rotation around the inner biphenyl carbon-carbon bond can hinder the overlap between the phenylene π systems, which reduces the efficiency of the transport properties of the biphenyl moiety.…”

“…[37] As an alternative to the biphenyl-alkynyl unit, a dialkylfluorenyl moiety can be considered, which differs from bi-phenyl by a C[(CH 2 ) n CH 3 ] 2 connectivity in the biphenyl backbone. [37,38] This connectivity fixes the phenylene units relative to each other in a planar conformation, in contrast to biphenyl in which possible rotation around the inner biphenyl carbon-carbon bond can hinder the overlap between the phenylene π systems, which reduces the efficiency of the transport properties of the biphenyl moiety. The dihedral angle of biphenyl in the gas phase is ca.…”

A New Approach for the Fabrication of Strongly Heterogeneous Mixed Self‐Assembled Monolayers

“…The syntheses of BPT and FBPET molecules are described elsewhere. [7] Primary SAMs were formed by immersion of freshly prepared gold substrates in a 1 mm solution of DDT in ethanol, BPT in toluene or FBPET in DMF for 24 h at room temperature. Electron irradiation was performed with 10 eV electrons at a base pressure of 10 À8 mbar.…”

“…This molecule comprises the electrochemically active ferrocene moiety and a conductive biphenyl foot. [7,8] Single-component DDT, BPT, and FBPET SAMs were prepared on the AuA C H T U N G T R E N N U N G (111) substrate by a standard procedure; [8,9] the BPT and FBPET films were used as references. DDT-BPT and DDT-FBPET mixed SAMs were fabricated by IPER as shown in Figure 1.…”