Demetriou Constantinos, Tzeli Demeter
Laboratory of Physical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, 15772 Athens, Greece.
Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 11635 Athens, Greece.
Molecules. 2025 Jul 6;30(13):2874. doi: 10.3390/molecules30132874.
Molybdenum lithium compounds and materials are being researched and applied in cutting-edge industries; however, their bonding has not been explored in a systematic way. The present study investigates the MoLi molecule, to shed light on its bonding. Specifically, the electronic structure and bonding of the ground and 40 low-lying states of the MoLi molecule are explored, employing multireference methodologies, i.e., CASSCF and MRCISD(+Q) in conjunction with the aug-cc-pV5z(-PP) basis set. Bond distances, dissociation energies, dipole moments as well as common spectroscopic constants are given, while the potential energy curves are plotted. For the ground state, XΣ+6, it is found that Re = 2.708 Å, De = 24.1 kcal/mol, ωe = 316.8 cm-1, ωexe = 2.11 cm-1, and = 3.63 D. Overall, the calculated states present a variety of bonds, from weak van der Waals up to the formation of 2.5 bonds. The dissociation energies of the calculated states range from 2.3 kcal/mol (aΣ+8) to 34.7 (cΠ4), while the bond distances range from 2.513 Å to 3.354 Å. Finally, dipole moment values up to 3.72 D are calculated. In most states, a 2s2pz hybridization on Li and a 4dz25s5pz or 5s5pz hybridization on Mo are found. Moreover, it is observed that the excited Li(P2) atom forms the shortest bonds because its empty 2s0 orbital can easily accept electrons, resulting in a strong σ dative bond. Finally, the present work highlights the exceptional ability of lithium atoms to participate in a variety of bonding schemes, and it could provide the opening gate for further investigation of this species or associated material and complexes.
钼锂化合物及材料正在前沿产业中得到研究和应用；然而，它们的键合情况尚未得到系统研究。本研究对MoLi分子进行了探究，以阐明其键合情况。具体而言，采用多参考方法，即CASSCF和MRCISD(+Q)并结合aug-cc-pV5z(-PP)基组，探索了MoLi分子基态及40个低激发态的电子结构和键合情况。给出了键长、解离能、偶极矩以及常见光谱常数，并绘制了势能曲线。对于基态XΣ+6，发现Re = 2.708 Å，De = 24.1 kcal/mol，ωe = 316.8 cm-1，ωexe = 2.11 cm-1，且 = 3.63 D。总体而言，计算得到的状态呈现出多种键合类型，从弱范德华键到形成2.5个键不等。计算状态的解离能范围为2.3 kcal/mol（aΣ+8）至34.7（cΠ4），而键长范围为2.513 Å至3.354 Å。最后，计算得到的偶极矩值高达3.72 D。在大多数状态下，发现Li上存在2s2pz杂化，Mo上存在4dz25s5pz或5s5pz杂化。此外，观察到激发态的Li(P2)原子形成的键最短，因为其空的2s0轨道能够轻松接受电子，从而形成强σ配位键。最后，本研究突出了锂原子参与多种键合模式的特殊能力，可为进一步研究该物种或相关材料及配合物打开大门。
