Bolivar-Pineda Lina M, Basiuk Elena V, Basiuk Vladimir A
Instituto de Ciencias Aplicadas y Tecnología, Universidad Nacional Autónoma de México, Circuito Exterior C.U., Ciudad de México, 04510, México.
Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior C.U., Ciudad de México, 04510, México.
J Mol Model. 2025 Jul 24;31(8):216. doi: 10.1007/s00894-025-06415-7.
Lanthanide-based systems, such as nitride cluster fullerenes LnN@C and bipthalocyanines LnPc (Pc = phthalocyanine ligand), are of interest for their magnetic, fluorescent and electronic properties. In this regard, we performed DFT characterization to investigate the changes in structure and electronic properties for noncovalently interacting lanthanide (Ln; where Ln = La, Ce, Gd and Lu) nitride cluster fullerenes and bisphthalocyanines to form LnN@C + LnPc dyads. The optimized geometries, formation and frontier orbital energies, HOMO-LUMO plots, charge and spin of Ln and N(NCF) atoms, as well as spin density plots of the dyads were analyzed in comparison with those of isolated LnN@C and LnPc components. In addition to LnPc bending distortion, the noncovalent dyad formation alters the geometry of the encapsulated LnN cluster, favoring more planar or pyramidal geometries, depending on the case. The HOMO and LUMO orbitals are found on bisphthalocyanines, being localized on the isoindole units, except for CeN@C + CePc dyad, where the LUMO was found on the central metal of CePc. The HOMO-LUMO gap energy is lower for the dyads compared to isolated NCFs, being rather close to the gap energy of bisphthalocyanines. The changes in spin density distribution are evident in the dyads containing Ce and Gd atoms, contrary to their La and Lu-derived counterparts. The interaction of CeN@C and GdN@C with CePc and GdPc, respectively, causes redistribution of the spin density, with changes in the orientation of spin-up and spin-down electrons in the encapsulated CeN and GdN clusters.
The geometry optimization and electronic properties calculations based on density functional theory were performed using the DMol module of Material Studio 8.0 software package from Accelrys Inc. The computational parameters selected included the general gradient approximation functional PBE, combined with a long-range dispersion correction developed by Grimme (PBE-D2), the double numerical basis set (DN), equivalent to the 6-31G Pople-type basis set along with the DFT semiconductor pseudopotentials. To mitigate the self-consistent field convergence problems, the thermal smearing technique was applied, with a final very small value of 0.0001 Ha (equivalent to 31.6 K temperature), or Fermi orbital occupancy in some cases.
基于镧系元素的体系，如氮化物团簇富勒烯LnN@C和双酞菁LnPc（Pc = 酞菁配体），因其磁、荧光和电子性质而备受关注。在这方面，我们进行了密度泛函理论（DFT）表征，以研究非共价相互作用的镧系元素（Ln；其中Ln = La、Ce、Gd和Lu）氮化物团簇富勒烯和双酞菁形成LnN@C + LnPc二元体系时结构和电子性质的变化。与孤立的LnN@C和LnPc组分相比，分析了二元体系的优化几何结构、形成能和前沿轨道能量、HOMO-LUMO图、Ln和N(NCF)原子的电荷与自旋，以及二元体系的自旋密度图。除了LnPc的弯曲畸变外，非共价二元体系的形成改变了包封的LnN团簇的几何结构，根据具体情况，更倾向于平面或金字塔形几何结构。发现HOMO和LUMO轨道位于双酞菁上，定域在异吲哚单元上，但CeN@C + CePc二元体系除外，其LUMO位于CePc的中心金属上。与孤立的氮化物团簇富勒烯相比，二元体系的HOMO-LUMO能隙能量更低，相当接近双酞菁的能隙能量。在含有Ce和Gd原子的二元体系中，自旋密度分布的变化很明显，这与由La和Lu衍生的二元体系相反。CeN@C和GdN@C分别与CePc和GdPc的相互作用导致自旋密度重新分布，包封的CeN和GdN团簇中自旋向上和自旋向下电子的取向发生变化。
基于密度泛函理论的几何结构优化和电子性质计算使用了Accelrys公司Material Studio 8.0软件包中的DMol模块。选择的计算参数包括广义梯度近似泛函PBE，并结合了Grimme开发的长程色散校正（PBE-D2）、双数值基组（DN），相当于6-3-1G Pople型基组以及DFT半导体赝势函数。为了减轻自洽场收敛问题，应用了热弥散技术，在某些情况下最终值非常小，为0.0001 Ha（相当于31.6 K温度）或费米轨道占有率。
