In the present contribution, we develop an adapted theoretical approach based on DFT calculations (B3LYP functional) and solution of the nuclear Schrödinger equation by using the Discrete Variable Representation method to model the interaction of ammonia with metallo-phthalocyanines (MPcs, where M = Fe, Co, Ni, Cu or Zn). This approach is intended to be a general protocol for the rational design of chemical sensors. The as-obtained binding energy curves, obtained from ab initio points, permitted us to calculate rovibrational energies and spectroscopic constants, as well as to establish the relative population of rovibrational states in different types of MPc-NH thermodynamic systems. Simulated binding energy curves show that the binding energy in MPc-NH systems is dependent on the type of M central ion, decreasing in the order FePc > ZnPc > CoPc > CuPc > NiPc, with values spanning from -170 to -16 kJ mol. Also, MPc-NH systems have at least 16 rovibrational levels, which confirms that they are all bound systems (chemically or physically). Despite that, only the interaction between ammonia and FePc, CoPc or ZnPc is spontaneous within the studied temperature range (200-700 K). NiPc and CuPc show a change between spontaneous and non-spontaneous behaviours at ∼400 K and ∼500 K, respectively. Less bound systems should more efficiently guarantee the sensors' signal reset, while they are also less specific than sensors built with medium to strongly bound systems. Moreover, the intermediate energy and spontaneous binding of ammonia to NiPc and CuPc at operation temperatures, as determined with our theoretical approach, suggests that these MPcs are most promising for ammonia sensors.

The photophysical behavior and reactive oxygen species (ROS) generation by chloroaluminum phthalocyanine (AlClPc) are evaluated by steady state absorption/emission, transient emission, and electron paramagnetic resonance spectroscopies in the presence of graphene oxide (GO), reduced graphene oxide (RGO), and carboxylated nanographene oxide (NGO). AlClPc and graphene oxides form a supramolecular structure stabilized by π-π interactions, which quantitatively quenches fluorescence emission and suppresses ROS generation. These effects occur even when graphenes are previously functionalized with Pluronic F-127. A small part of quenching is due to an inner filter effect, in which graphene oxides compete with AlClPc for light absorption. Nonetheless, most of the (static) quenching arises on the formation of a nonemissive ground state complex between AlClPc and graphene oxides. The efficiency of graphene oxides on the fluorescence quenching and ROS generation suppression follows the order: GO < NGO < RGO.

Neste trabalho, apresentaram-se resultados de cálculos das energias e constantes espectroscópicas rovibracionais do sistema molecular Cl2 em diferentes estados eletrônicos. Foram realizados cálculos de 20 estados eletrônicos, utilizando as funções de Rydberg e Bond Order generalizadas como formas analíticas para ajustar as curvas de energia potencial, geradas a partir das energias eletrônicas. Com essas formas analíticas, as energias rovibracionais e as constantes espectroscópicas foram determinadas, combinando as energias obtidas via solução da Equação de Schrödinger Nuclear com uma equação espectroscópica e via método de Dunham. As constantes espectroscópicas obtidas estão em excelente acordo com os dados experimentais disponíveis para alguns estados eletrônicos.