Binzhou Key Laboratory of Material Chemistry, Department of Chemistry and Chemical Engineering, Binzhou University, Binzhou 256603, People's Republic of China.
J Mol Model. 2013 Aug;19(8):3219-24. doi: 10.1007/s00894-013-1846-4. Epub 2013 May 1.
A density functional theory (DFT) investigation into the structures and bonding characteristics of (B3O3H3)nM(n = 1, 2;M = Cu, Ag, Au) complexes was performed. DFT calculations and natural bond orbital (NBO) analyses indicate that the ΙB metal complexes of boroxine exhibit intriguing bonding characteristics, different from the typical cation-π interactions between ΙB metal-cations and benzene. The complexes of B3O3H3M and (B3O3H3)2 M (M = Cu, Ag, and Au) favor the conformation of perfectly planar structures with the C2v and D2h symmetry along one of the threefold molecular axes of boroxine, respectively. Detailed natural resonance theory (NRT) and canonical molecular orbitals (CMOs) analyses show that interaction between the metal cation and the boroxine in B3O3H3M (M = Cu, Ag, and Au) is mainly ionic, while the ΙB metal-cations←π donation effect is responsible for the binding site. In these complexes, boroxine serves as terminals η(1)-B3O3H3 with one O atom of the B3O3 ring. The infra-red (IR) spectra of B3O3H3M were simulated to facilitate their future experimental characterization. The complexes all give two IR active modes at about 1,300 and 2,700 cm(-1), which are inactive in pure boroxine. Simultaneously, the B-H stretching modes of the complexes are red-shifted due to the interaction between the metal-cation and boroxine. To explore the possibility of the structural pattern developed in this work forming mesoporous materials, complexes (B3O3H3M)6 (M = Cu, Ag, and Au) were also studied, which appear to be unique and particular interesting: they are all true minima with D6h symmetries and pore sizes ranging from 12.04 Å to 13.65 Å.
采用密度泛函理论（DFT）方法对(B3O3H3)nM（n=1,2；M=Cu,Ag,Au）配合物的结构和键合特性进行了研究。DFT 计算和自然键轨道（NBO）分析表明，硼氧烷的ΙB 金属配合物表现出有趣的键合特性，与 ΙB 金属阳离子与苯之间典型的阳离子-π相互作用不同。B3O3H3M和(B3O3H3)2M（M=Cu,Ag,Au）配合物倾向于采用完全平面结构，分别沿硼氧烷的三个分子轴之一具有 C2v 和 D2h 对称性。详细的自然共振理论（NRT）和典型分子轨道（CMOs）分析表明，B3O3H3M（M=Cu,Ag,Au）中金属阳离子与硼氧烷之间的相互作用主要是离子性的，而 ΙB 金属阳离子←π供电子作用是结合位的原因。在这些配合物中，硼氧烷作为末端 η(1)-B3O3H3，硼氧三环的一个 O 原子与金属阳离子配位。模拟了B3O3H3M的红外（IR）光谱，以方便对其进行未来的实验表征。这些配合物都在大约 1300 和 2700 cm(-1) 处给出两个 IR 活性模式，而在纯硼氧烷中则是无活性的。同时，由于金属阳离子与硼氧烷之间的相互作用，配合物的 B-H 伸缩模式发生红移。为了探索本工作中开发的结构模式形成介孔材料的可能性，还研究了(B3O3H3M)6（M=Cu,Ag,Au）配合物，它们似乎具有独特而特别有趣的性质：它们都是具有 D6h 对称性的真正最小值，孔径范围从 12.04 Å 到 13.65 Å。
