Formation of one-dimensional C60 rows on TiO2(110)-1x2-cross-link structure and their local polymerization

Adsorption and growth of a C-60 monolayer on a TiO2(110)-1 x 2-cross-link structure were investigated by scanning tunneling microscopy (STM). Single C-60 molecules were preferentially anchored at the cross-link site due to interaction with undercoordinated Ti cations, and C-60 rows grew along the troughs between the 1 x 2-added rows. The C-60 monolayer structure is characterized by closely packed (r(C-60-C-60) = 1.0 nm) C-60 rows that are paired with every second added row (separation of paired rows is 1.1 nm). By applying a high negative bias voltage (-3.5 V) to an STM tip on the C-60 monolayer, C-60 oligomers were formed accompanied with the contraction of C-60-C-60 distance along the C-60 row and bright contrast in the STM image.