Baggio Alan R, Machado Daniel F S, Carvalho-Silva Valter H, Paterno Leonardo G, de Oliveira Heibbe Cristhian B
Laboratório de Estrutura Eletrônica e Dinâmica Molecular (LEEDMOL), Institute of Chemistry, University of Brasília, Campus Darcy Ribeiro, Brasília, Brazil.
Phys Chem Chem Phys. 2017 May 3;19(17):10843-10853. doi: 10.1039/c6cp07900h.
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.
在本论文中，我们基于密度泛函理论（DFT）计算（B3LYP泛函）以及采用离散变量表示法求解核薛定谔方程，开发了一种经过改进的理论方法，用于模拟氨与金属酞菁（MPc，其中M = Fe、Co、Ni、Cu或Zn）之间的相互作用。该方法旨在成为一种用于化学传感器合理设计的通用方案。从第一性原理计算得到的结合能曲线，使我们能够计算振转能量和光谱常数，并确定不同类型的MPc-NH热力学系统中振转态的相对丰度。模拟的结合能曲线表明，MPc-NH系统中的结合能取决于中心离子M的类型，其顺序为FePc > ZnPc > CoPc > CuPc > NiPc，值范围为-170至-16 kJ/mol。此外，MPc-NH系统至少有16个振转能级，这证实它们都是束缚系统（化学或物理束缚）。尽管如此，在所研究的温度范围（200 - 700 K）内，只有氨与FePc、CoPc或ZnPc之间的相互作用是自发的。NiPc和CuPc分别在约400 K和约500 K时显示出自发与非自发行为之间的转变。束缚较弱的系统应能更有效地保证传感器信号重置，但其特异性也低于由中等至强束缚系统构建的传感器。此外，通过我们的理论方法确定，在工作温度下氨与NiPc和CuPc的中间能量和自发结合表明，这些MPc对氨传感器最具潜力。
