Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand 247667, India.
Phys Chem Chem Phys. 2019 Apr 3;21(14):7605-7612. doi: 10.1039/c9cp00442d.
The endohedral heterofullerenes (B@C59B)2, (B@C59N)2, (N@C59B)2 and (B@C59N-N@C59B) are investigated using dispersion corrected density functional theory. Several spin states of these complexes are considered and their stable spin states are reported. For 1[(B@C59B)2] and 1[(B@C59N-N@C59B)], the encapsulated atoms are positioned near the surface of the host cages, in contrast to other spin states where they are positioned at the centre of the cages. In complexes 1[(B@C59N)2], 3[(B@C59N)2] and 7[(N@C59B)2], the guest atoms are found to be at the centre of the host cages. The spin polarization and the transfer of spin density between the components of the complexes for different stable spin states are analyzed. Based on the spin states of the complexes, the spin-spin interaction is found to be either ferromagnetic or anti-ferromagnetic. Unlike other complexes, in 1[(B@C59B)2] and 1[(B@C59N-N@C59B)] the spin density is transferred from the guest to the host followed by anti-ferromagnetic coupling between the monomers. The thermodynamic feasibility of formation of the complexes is also examined. The electron affinity, ionization potential and dipole moment of the above systems are determined. The singlet state of the heterodimer (B@C59N-N@C59B) showed high polarity due to the slight rotation along the dihedral angle φNCCB.
用含色散校正的密度泛函理论研究了笼内杂富勒烯 (B@C59B)2、(B@C59N)2、(N@C59B)2 和 (B@C59N-N@C59B)。考虑了这些配合物的几种自旋态，并报告了它们的稳定自旋态。对于 1[(B@C59B)2] 和 1[(B@C59N-N@C59B)]，被包封的原子位于主体笼的表面附近，而在其他自旋态下，它们位于笼的中心。在配合物 1[(B@C59N)2]、3[(B@C59N)2] 和 7[(N@C59B)2] 中，客体原子位于主体笼的中心。分析了不同稳定自旋态下配合物各组分之间的自旋极化和自旋密度转移。根据配合物的自旋态，发现自旋-自旋相互作用为铁磁或反铁磁。与其他配合物不同，在 1[(B@C59B)2] 和 1[(B@C59N-N@C59B)]中，自旋密度从客体转移到主体，随后单体之间发生反铁磁耦合。还检查了配合物形成的热力学可行性。确定了上述体系的电子亲和能、电离势和偶极矩。杂二聚体 (B@C59N-N@C59B) 的单重态由于沿二面角 φNCCB 的轻微旋转而表现出高极性。
