Optical characterization and analysis of the gas/surface adsorption phenomena on phthalocyanines thin films for gas sensing application

Synthesis of novel azo-bridged phthalocyanines and their toluene vapour sensing properties

“…For a particular gas, the intensity and kinetics of these interactions are related to the nature of the Pc compound used as the sensitive material, the charge transport process, relative orientation, and separation of adjacent molecules, etc. It has been previously reported that the relevant factors in the volatile organic compound (VOC) vapour/MPc interaction mechanisms are the conjugatedelectron system, the presence of heteroatoms and the central metal atom [24,29]. In the case of substituted Pcs, the substituents in macrocycle may offer another possible site for complexation.…”

“…It is also believed that the central metal ion together with the peripheral substituents acts as two different sites of interaction with the analyte molecules. Spadavecchia et al reported in one of their studies that a primary interaction involves the Pc metal and the heteroatoms on the analyte molecule and a secondary interaction is determined by the peripheral substituents [29]. The increase in the conductivity could be interpreted, bearing in mind that Pcs are p-type semiconductors, in terms of charge-transfer interaction between the Pc molecule and toluene vapour.…”

Ammonia adsorption on iron phthalocyanine on Au(111): Influence on adsorbate–substrate coupling and molecular spin

“…[2][3][4][5][6][7] Such monolayers are promising candidates for novel catalytic [8][9][10][11][12] and gas sensing applications. [13][14][15][16][17][18][19][20][21][22][23][24][25][26] Their function will depend critically on the molecular electronic structure, which for phthalocyanines containing certain transition metals (such as Cr, Mn, Fe, Co) is quite complex with an open shell structure of the d orbitals and a number of energetically close-lying electronic states. These states can easily be modified by, e.g., changes in the structure of the support surface and the addition of molecular functional groups, but also, as pursued here, by the adsorption of further ligands.…”

Optical amine sensor based on metallophthalocyanine

“…It is likely that the weak coordination of the amine molecule at the metal site does not cause large perturbation of the conjugated p system, but only increases the transition probabilities of the p ! p* transitions (Spadavecchia et al, 2005). The reversibility of the adsorption process is indicated by the full recovery of the spectrum back to its pre-adsorption state after purging with N 2 , as shown in Fig.…”