Mermigki Markella A, Karapetsas Ioannis, Tzeli Demeter
Laboratory of Physical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, Athens, 157 84, Greece.
Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Ave, Athens, 116 35, Greece.
Chemphyschem. 2023 Nov 2;24(21):e202300365. doi: 10.1002/cphc.202300365. Epub 2023 Aug 24.
Molybdenum disulfide (MoS ) is the building component of 1D-monolayer, 2D-layered nanosheets and nanotubes having many applications in industry, and it is detected in various molecular systems observed in nature. Here, the electronic structure and the chemical bonding of sixteen low-lying states of the triatomic MoS molecule are investigated, while the connection of the chemical bonding of the isolated MoS molecule to the relevant 2D-MoS , is emphasized. The MoS molecule is studied via DFT and multireference methodologies, i. e., MRCISD(+Q)/aug-cc-pVQZ(-PP) . The ground state, B , is bent (Mo-S=2.133 Å and ϕ(SMoS)=115.9°) with a dissociation energy to atomic products of 194.7 kcal/mol at MRCISD+Q. In the ground and in the first excited state a double bond is formed between Mo and each S atom, i. e., . These two states differ in which d electrons of Mo are unpaired. The Mo-S bond distances of the calculated states range from 2.108 to 2.505 Å, the SMoS angles range from 104.1 to 180.0°, and the Mo-S bonds are single or double. Potential energy curves and surfaces have been plotted for the B , A and B states. Finally, the low-lying septet states of the triatomic molecule are involved in the material as a building block, explaining the variety of its morphologies.
二硫化钼（MoS₂）是一维单层、二维层状纳米片和纳米管的构建成分，在工业中有许多应用，并且在自然界观察到的各种分子系统中都能检测到。在此，我们研究了三原子MoS₂分子的16个低能态的电子结构和化学键，同时强调了孤立的MoS₂分子的化学键与相关二维MoS₂的联系。通过密度泛函理论（DFT）和多参考方法，即MRCISD(+Q)/aug-cc-pVQZ(-PP)对MoS₂分子进行了研究。基态¹B₁是弯曲的（Mo-S = 2.133 Å且ϕ(SMoS)=115.9°），在MRCISD+Q水平下到原子产物的解离能为194.7 kcal/mol。在基态和第一激发态中，Mo与每个S原子之间形成双键，即。这两个态的区别在于Mo的d电子的不成对情况。计算态的Mo-S键长范围为2.108至2.505 Å，SMoS角范围为104.1至180.0°，且Mo-S键为单键或双键。已绘制了¹B₁、¹A₁和³B₁态的势能曲线和势能面。最后，三原子分子的低能七重态作为构建单元参与到材料中 [100]，解释了其形态的多样性。
