Synthesis of Bis(silylene) Iron Chlorides and Their Catalytic Activity for Dinitrogen Silylation.

In this study, three tetracoordinated bis(silylene) iron(II) chlorides, namely, [SiCHRSi]FeCl () (R = H), () (R = CH), and () (R = Ph), were synthesized through the reactions of the three different bis(silylene) ligands [LSiCHRSiL] (L = PhC(NtBu), (R = H), (R = CH), (R = Ph)) with FeCl·(THF) in THF. The bis(silylene) Fe complexes could be used as effective catalysts for dinitrogen silylation, with complex demonstrating the highest turnover number (TON) of 746 equiv among the three complexes. The catalytic mechanism was explored, revealing the involvement of the pentacoordinated bis(dinitrogen) iron(0) complexes [SiCHRSi]Fe(N)(THF), ()(), as the active catalysts in the dinitrogen silylation reaction.

Impact of the 2,2'-Bithienyl Framework on the Charge-Transfer Emission of Triarylborane-Based o,o'-Substituted Biaryls.

Two new triarylborane-based o,o'-substituted 2,2'-bithienyls, and , which contain BMes and NMe/NBn groups at the 3,3'-positions, have been synthesized. Similar to the o,o'-substituted biphenyl analogues, and , which contain BMes and NMe/NBn groups at the 2,2'-positions, the steric effect of the amino group has significant influence on the conformation of the 2,2'-bithienyl skeleton. The boryl and amino groups are located at the same side of 2,2'-bithienyls axis with a short B···N distance (3.

A triarylborane-based biphenyl exhibiting abrupt fluorescence enhancement at a specific high temperature.

A triarylborane-based biphenyl, 4,4'-dibromo-2-dimesitylboryl-2'-(N,N-dimethylamino)biphenyl (Br2-BN-BPh), exhibits very unique temperature-dependent fluorescence behavior. Although Br2-BN-BPh is weakly emissive at room temperature, its fluorescence increases abruptly at a specific high temperature (68 °C in MOE, 88 °C in toluene). In addition, the fluorescence still remains very strong even after cooling to room temperature, providing the possibility of the fluorescence detection of a specific high temperature.

Charge-Transfer Emitting Triarylborane π-Electron Systems.

Triarylboranes have attracted significantly increasing research interest as a remarkable class of photoelectronic π-electron materials. Because of the presence of vacant p orbital on the B center, the boryl group is a very unique electron acceptor that exhibits not only electron-accepting ability through p-π* conjugation but also high Lewis acidity to coordinate with Lewis bases and steric bulk arising from the aryl substituent on the B center to get enough kinetic stability. Thus, the incorporation of a trivalent B element into π-conjugated systems is an efficient strategy to tune the electronic and stereo structures and thus the photoelectronic properties of π-electron systems.

Experimental computed tomography-guided vena cava puncture in pigs for percutaneous brachytherapy of middle mediastinal lymph node metastases.

Background: Percutaneous brachytherapy is a valuable method for the treatment of lung cancer and mediastinal lymph nodes metastasis. However, in some of the metastatic lymph nodes in the middle mediastinum, the percutaneous approach cannot be used safely due to possible damage to surrounding anatomical structures. We established an animal model (group of 12 pigs) to assess the safety and feasibility of computed tomography (CT)-guided vena cava puncture.

Source apportionment of polycyclic aromatic hydrocarbons in surface sediment of mud areas in the East China Sea using diagnostic ratios and factor analysis.

Polycyclic aromatic hydrocarbons (PAHs) and aliphatic hydrocarbons (AHs) have been quantified for surface sediments collected from the East China Sea (ECS). Our results showed that relatively high levels of PAHs and AHs occurred in both the inner and outer mud areas, while their concentrations at the control site were much lower. AHs for all samples were dominated by the unresolved complex mixture (UCM).