Coordination reaction between tetraphenylporphyrin and nickel on a TiO₂(110) surface

Abstract

In situ metalation of tetraphenylporphyrin (2HTPP) (sub)monolayers with Ni on a TiO2(110) surface to nickel(II)-tetraphenylporphyrin (NiTPP) depends on temperature and order of deposition, and affects conformation and bonding geometry of the porphyrin.

Surface chemistry of porphyrins and phthalocyanines

“…On a TiO 2 (1 1 0)-(1 Â 1) surface, 2HTPP (sub)monolayers were metalated with post-deposited Ni atoms. The yield was found to be lower than in the case of metalation on metal surfaces: only 60% were metalated even with a Ni/2HTPP ratio of 3:1, i. e., a three-fold stoichiometric excess of Ni [624].…”

“…In contrast, deposition of CoPc at room temperature led to mobile molecules [321]. For 2HTPP and NiTPP on TiO 2 (1 1 0), it was found that both molecules bind to the oxygen rows and that they are rotated by 451 relative to each other [624]. See also Table 4.…”

“…In contrast, the metalated species (NiTPP) had a four-fold molecular symmetry and was rotated by 451, such that the diagonal of the square molecules was aligned along the oxygen rows. These metalation-induced changes were interpreted with an alteration of the adsorbate-substrate bonding mechanism [624].…”

A Surface Chemical Reaction in Organic–Inorganic Materials Using a New Chemical Evaporation System

“…[1][2][3][4][5] For instance, various applications of porphyrin-related materials, such as the light-absorbing components in dye sensitized solar cells [6][7][8][9] , active layers for organic thin film transistors [10][11] , and multi-functional sensors [12][13][14] , have been developed. Previous studies have been reported the porphyrin metalation involving the coordination with post-or pre-deposited metal atoms on well-defined metal or metal oxide substrate [15][16][17][18][19][20][21] or vapor phase-metalation by atomic layer deposition process. 22 In the former case, this synthesis is not appropriate for the preparation of multi-stacked metalloporphyrin thin films.…”

Thermally induced anchoring of a zinc-carboxyphenylporphyrin on rutile TiO2 (110)

“…Consequently, many different porphyrin-titania systems have been investigated under ultra-high vacuum (UHV) conditions by scanning probe techniques and photoelectron spectroscopy (PES). [21][22][23][24][25][26][27][28][29][30][31] Carboxylic acid substituents have often been used for immobilization of porphyrins on TiO 2 . 14,19 However, for relatively large porphyrins, which have been evaporated to the surface, it is often not clear if the anchoring group really undergoes reaction with the surface.…”