Synthesis of Polyhedral Borane Cluster Fused Heterocycles via Transition Metal Catalyzed B-H Activation

Aromatic heterocycles are ubiquitous building blocks in bioactive natural products, pharmaceutical and agrochemical industries. Accordingly, the carborane-fused heterocycles would be potential candidates in drug discovery, nanomaterials, metallacarboranes, as well as photoluminescent materials. In recent years, the transition metal catalyzed B-H activation has been proved to be an effective protocol for selective functionalization of B-H bond of o-carboranes, which has been further extended for the synthesis of polyhedral borane cluster-fused heterocycles via cascade B-H functionalization/annulation process. This article summarizes the recent progress in construction of polyhedral borane cluster-fused heterocycles via B-H activation.

Introducing borane clusters into polymeric frameworks: architecture, synthesis, and applications

This feature article summarizes the preparation and applications of borane cluster-containing polymers and covers research progress and future trends of borane cluster-containing linear, dendritic, macrocyclic polymers and metal–organic frameworks.

11B-NMR shielding effects in theclosoborane series: sensitivity of shifts and their additivity

NMR shielding effects for [Xm-closo-BnHn−m]2−anions exhibit a simple linear behaviour in all positions of the borane cluster.

Designing nonlinear optical molecule by incorporating the planar tetracoordinate unit NAl4- or CAl42- into decaborane B10H14

Molecular Incorporation is an important approach of providing novel compounds with fascinating structures. In this paper, we theoretically described the incorporation of the central planar tetracoordinate molecules NAl 4- or CAl 42- into borane cluster B 10 H 14. By molecular orbital analysis, a novel four-fold Al – H bonding interaction was found, and it contributes to the molecular incorporation. In addition, we found that the counterion Li + is critical for the neutral incorporation species, due to its small atomic radii and little positive charge. To measure the nonlinear optical (NLO) response, the static first hyperpolarizabilities (β0) were evaluated at the second-order Møller–Plesset (MP2) level. The β0 values are 1708 a.u and 8682 a.u for [ B 10 H 14⋯ NAl 4]- and [ B 10 H 14⋯ CAl 4]2-, respectively, which indicates that the charge plays a significant role on deciding the value of β0. Moreover, it is different for the change of β0 value brought by counterion Li +. Li + decreases the β0 value of [ B 10 H 14⋯ CAl 4]2-, while it increases the β0 value of [ B 10 H 14⋯ NAl 4]-, therein, the sandwich-like B 10 H 14– Li – NAl 4( I ) exhibits considerable β0 value (31,253 a.u.). This reveals that it is possible to explore high-performance NLO materials based on suitable molecular incorporation. Besides, the present study is also expected to enrich the knowledge of the planar tetracoordinate carbon chemistry and boron chemistry.

DFT studies of the σ-donor/π-acceptor properties of [SnCB10H11]– and its relationship to [SnCl3]–, CO, PF3, [SnB11H11]2–, SnC2B9H11, and related SnC2BnHn+2 compounds

The 1,2-carbastanna-closo-dodecaborate, [SnCB10H11]–, was found via DFT calculations to have intermediate σ-donor/π-acceptor properties between those of [SnB11H11]2– and 3,1,2-SnC2B9H11, and quite similar HOMO and LUMO energies and shapes to those of [SnCl3]–, which is a stronger σ-donor and weaker π-acceptor than CO or PF3. The non-carbon containing cluster [SnB11H11]2– is shown to be a very strong donor, whereas the dicarbon cluster 3,1,2-SnC2B9H11 is a poor σ-donor but good Lewis acid, consistent with experimental results. Thus, these systems can be tuned across a very wide range via isolobal replacement of [BH]– for CH vertices. The higher negative charge in the non-carbon-containing systems, as well as the fact that boron is more electropositive than carbon, contribute to the increased energies of both HOMO and LUMO in the stannaboranes compared to the stannacarboranes, explaining their relative donor and acceptor properties.Key words: DFT calculations, tin, borane cluster.