Boron doped diamond (BDD) shows high chemical stability in contact with a liquid phase even under extreme pH conditions, high electrochemical activity, and allows very stable covalent functionalization on O-or N-terminated surfaces. It is therefore an excellent electrode material for many applications such as analytics, biosensors, and purification. Furthermore, the electrodes can be covalently functionalized with photosensitive dyes to generate photo currents. However, the energetic conditions and charge transfer mechanisms are not fully known and therefore have been investigated in this work. The focus was set on the energy band diagrams of nanocrystalline diamond (NCD) layers, especially on the flat-band potential V F and the band-bending w B in the space charge layer, for both O-and N-terminated surfaces, and the charge transfer mechanisms at the semiconductor/electrolyte phase-boundary, with or without electro-active organic dyes, such as manganese phthalocyanine. For this study NCD samples were grown by hot filament chemical vapor deposition (HFCVD) with a boron doping density N A ranging between 5.8 and 9.6 Â 10 20 cm À3 .The pristine surface was then processed by oxygen or ammonia plasma to modify the termination to O and NH 2 , respectively. After that a series of Mott-Schottky plots was measured for both terminations at several frequencies spanning from 3 Hz to 10 kHz and in two different electrolytes, namely 0.1 M H 2 SO 4 and 0.1 M KCl. The results showed nearly the same flat-band potential for both surface terminations, but a remarkable difference in the band-bending. The latter is most probably responsible for the better photoelectrical conversion observed in N-terminated NCD samples. The open-circuit potential (OCP) and chronoamperometric measurements performed after covalent functionalization of the samples with the color dyes revealed that only the N-terminated material delivered a measurable photocurrent. Although the global efficiency of the photoelectric conversion was low, these initial results show that by optimized selection of materials and modification technologies providing a proper match of the energy levels at all charge transfer steps, a higher energy output could be achieved.

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4,5-Bis(n-octylseleno)phthalodinitrile and 4,5-bis(ndodecylseleno)phthalodinitrile were efficiently synthesised from 4,5-dichlorophthalodinitrile and the corresponding selenolate RSeMgBr (prepared in situ from elemental selenium and RMgBr; R = n-octyl, n-dodecyl). Lithium chloride was essential for achieving the substitution of both chloro substituents. The crystal structures of the monosubstitution product 4-chloro-5n-octylselenophthalodinitrile and both disubstitution products were determined by single-crystal X-ray diffraction, with that of 4,5-bis(n-dodecylseleno)phthalodinitrile exhibiting inter- [a] 5610 molecular C-H···Se contacts compatible with hydrogen bonds. Cyclotetramerisation of these 4,5-bis(n-alkylseleno)phthalodinitriles under Tomoda conditions afforded the corresponding 2,3,9,10,16,17,23,24-octakis(n-alkylseleno)phthalocyanines Pc SeR H 2 (R = n-octyl, n-dodecyl). The phthalocyaninatomanganese(III) complexes [MnCl(Pc SeR )] were obtained from the cyclotetramerisation in the presence of manganese(II) chloride after aerobic workup. The use of terbium(III) chloride as metal salt in the cyclotetramerisation furnished the "double-decker" complexes [Tb(Pc SeR ) 2 ].