Diamond functionalization with light-harvesting molecular wires: improved surface coverage by optimized Suzuki cross-coupling conditions

Abstract

Donor-acceptor type light-harvesting molecular wires are covalently attached to a boron-doped diamond surface via a combination of diazonium electrografting and Suzuki cross-coupling. For the Suzuki reaction, various catalytic systems are compared with respect to their imposed surface coverage. Combining 2dicyclohexylphosphino-2 0 ,6 0-dimethoxybiphenyl (SPhos) and Pd(0), the diamond coverage improves considerably (by 98%) as compared to the standard tetrakis(triphenylphosphine)palladium(0) (Pd(PPh 3) 4) catalyst. As the energy levels between the molecular chromophores and the diamond film align well, the sophisticated functionalized diamond surfaces present a first step towards the development of fully carbon-based devices for light to electricity conversion.

Efficiency and stability of spectral sensitization of boron-doped-diamond electrodes through covalent anchoring of a donor–acceptor organic chromophore (P1)

“…However, both P1@BDD and pure P1 decompose under the laser light (see Fig. 16 Hence, we estimate a nearly monolayer coverage in our case too. Photoelectron spectra (XPS; Fig.…”

“…17). 10,[13][14][15][16] Nevertheless, the photoelectrochemical performance of the sensitized BDD is still far from that of sensitized p-NiO, the latter exhibiting photocurrents in the mA cm À2 domain for good samples. 6) is ca.…”

“…10 Sensitization of BDD by Ru(SCN) 2 (2,2 0 -bipyridine, 4,4 0 -dicarboxylate) 2 (coded N3) 14 provided photocurrents of the order of 1-10 nA cm À2 under 1 Sun. 15 Yeap et al 16 modified BDD with thiophene derivatives, and observed a photocurrent of ca. They observed photocurrents of about 0.3 mA cm À2 under NIR light (870 nm; unspecified intensity).…”

Electrochemical impedance spectroscopy of polycrystalline boron doped diamond layers with hydrogen and oxygen terminated surface

“…Diamond can be modified by different surface functional groups ranging from simple heteroatom-termination of the carbonaceous skeleton to targeted chemical modifications for achieving specific electrochemical [1,4] and photoelectrochemical [7][8][9] functions. The most common surface terminations include oxygen (OT) and hydrogen (HT) atoms, which is associated with different wettability of the diamond (HT surface is hydrophobic, OT surface is hydrophilic).…”

Expanding the Scope of Diamond Surface Chemistry: Stille and Sonogashira Cross-Coupling Reactions

“…55 Similar catalyst systems have previously been used to optimize the Suzuki cross-coupling of light-harvesting molecular wires on B:NCD films. 35 Encouraged by these results, some of these conditions were also applied for the Stille functionalization of B:NCD (Table 2). For the more advanced catalytic systems, high concentrations of Pd and Sn were always observed, while the signal corresponding to the B 1s peak was not detected.…”