通过密度泛函理论计算研究含乙炔配体[OsN(C≡CR)4]-（R = H、CH3和Ph）的氮合锇(VI)配合物的电子结构和光谱性质

Electronic structures and spectroscopic properties of nitrido-osmium(VI) complexes with acetylide ligands [OsN(C[Triple Bond]CR)4]- R=H, CH3, and Ph by density functional theory calculation.

作者信息

Zhang Yu-Hua, Xia Bao-Hui, Pan Qing-Jiang, Zhang Hong-Xing

机构信息

State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China.

出版信息

J Chem Phys. 2006 Apr 14;124(14):144309. doi: 10.1063/1.2189220.

DOI:10.1063/1.2189220

PMID:16626198

Abstract

Electronic structures and spectroscopic properties of a series of nitrido-osmium (VI) complex ions with acetylide ligands, OsN(C[Triple Bond]CR)(4) (R[Double Bond]H, (1), CH(3) (2), and Ph (3)) were investigated theoretically. The structures of the complexes were fully optimized at the B3LYP and CIS level for the ground states and excited states, respectively. The calculated bond lengths of Os[Triple Bond]N (1.639 A in 1, 1.642 A in 2, and 1.643 A in 3) and Os-C (2.040 A in 1, 2.043 A in 2, and 2.042 A in 3) in ground state agree well with the experimental results. The bond length of Os[Triple Bond]N bond is lengthened by ca. 0.13 A in the A (3)B(2) excited state compared to the (1)A(1) ground state, which is consistent with the lower vibration frequency of nu(Os-N) ( approximately 780 cm(-1)) in the excited state than that ( approximately 1175 cm(-1)) in the ground state. Among the calculated dipole-allowed absorptions at lambda>250 nm, the intense absorption at 261 nm for 1, 266 nm for 2, and 300 nm for 3 were attributed to the (1)[pi(C[Triple Bond]C)]-->(1)[pi()(N[Triple Bond]Os)+pi()(C[Triple Bond]C)], (1)[pi(C[Triple Bond]C)]-->(1)[pi()(N[Triple Bond]Os)+pi()(C[Triple Bond]C)], and (1)[pi(C[Triple Bond]CPh)]-->(1)[pi()(N[Triple Bond]Os)+pi()(C[Triple Bond]CPh)], respectively. The lowest energy absorption at lambda(max)=393 nm for 1, 400 nm for 2, and 400 nm for 3 were assigned as (1)[d(xy)(Os)+pi(C[Triple Bond]C)]-->(1)[pi()(N[Triple Bond]Os)+pi()(C[Triple Bond]C)], (1)[d(xy)(Os)+pi(C[Triple Bond]C)]-->(1)[pi()(N[Triple Bond]Os)+pi()(C[Triple Bond]C)], and (1)[d(xy)(Os)+pi(C[Triple Bond]CPh)]-->(1)[pi()(N[Triple Bond]Os)+pi()(C[Triple Bond]CPh)], respectively. The calculated phosphorescence emission at lambda(max)=581 nm for 1, 588 nm for 2, and 609 nm for 3 were originated from (3)[(pi()(N[Triple Bond]Os)+pi()(C[Triple Bond]C))(1)(d(xy)(Os)+pi(C[Triple Bond]C))(1)], (3)[(pi()(N[Triple Bond]Os)+pi()(C[Triple Bond]C))(1)(d(xy)(Os)+pi(C[Triple Bond]C))(1)], and (3)[(pi()(N[Triple Bond]Os)+pi()(C[Triple Bond]CPh))(1)(d(xy)(Os)+pi(C[Triple Bond]CPh))(1)] excited state, respectively.

摘要

理论上研究了一系列具有乙炔配体的氮合锇（VI）络合离子[OsN(C≡CR)₄]⁻（R = H，(1)；CH₃，(2)；Ph，(3)）的电子结构和光谱性质。分别在B3LYP和CIS水平上对基态和激发态的络合物结构进行了完全优化。计算得到的基态下Os≡N键长（(1)中为1.639 Å，(2)中为1.642 Å，(3)中为1.643 Å）和Os - C键长（(1)中为2.040 Å，(2)中为2.043 Å，(3)中为2.042 Å）与实验结果吻合良好。与¹A₁基态相比，在A₃B₂激发态下Os≡N键长延长了约0.13 Å，这与激发态下ν(Os - N)的振动频率（约780 cm⁻¹）低于基态下（约1175 cm⁻¹）相一致。在计算得到的λ>250 nm的允许偶极吸收中，(1)在261 nm、(2)在266 nm和(3)在300 nm处的强吸收分别归因于(1)[π(C≡C)]→(1)[π*(N≡Os)+π*(C≡C)]、(1)[π(C≡C)]→(1)[π*(N≡Os)+π*(C≡C)]和(1)[π(C≡CPh)]→(1)[π*(N≡Os)+π*(C≡CPh)]。(1)在λmax = 393 nm、(2)在400 nm和(3)在400 nm处的最低能量吸收分别被指定为(1)[d(xy)(Os)+π(C≡C)]→(1)[π*(N≡Os)+π*(C≡C)]、(1)[d(xy)(Os)+π(C≡C)]→(1)[π*(N≡Os)+π*(C≡C)]和(1)[d(xy)(Os)+π(C≡CPh)]→(1)[π*(N≡Os)+π*(C≡CPh)]。计算得到的(1)在λmax = 581 nm、(2)在588 nm和(3)在609 nm处的磷光发射分别源于(³)[(π*(N≡Os)+π*(C≡C))¹(d(xy)(Os)+π(C≡C))¹]、(³)[(π*(N≡Os)+π*(C≡C))¹(d(xy)(Os)+π(C≡C))¹]和(³)[(π*(N≡Os)+π*(C≡CPh))¹(d(xy)(Os)+π(C≡CPh))¹]激发态。