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Two new N-heterocyclic carbene (NHC) ligands bearing 2-morpholino and 2-piperidinyl naphthyl wingtips were synthesised (2-SIMorNap and 2-SIPipNap). Nuclear magnetic resonance studies, in conjunction with crystal structures and derivatisation of the NHC salts using a chiral counteranion, revealed that the ligand wingtips are oriented anti with respect to each other. From the free carbene, palladium, ruthenium and iridium complexes were prepared. NHC–iridium dicarbonyl complexes were made in order to extract the TEP values for these ligands. The study showed that these NHC ligands are more electron-donating than normal, aryl-substituted NHCs. The palladium complexes were tested in representative Suzuki–Miyaura cross-coupling reactions and compared to the state of the art systems. Ruthenium-catalysed ring-closing metathesis with these ligands was also performed. It was found that Grubbs’ 2nd generation catalyst incorporating 2-SIPipNap did not initiate at room temperature and required heating for RCM to occur.

Enantiomerically pure diarylmethylamines are important building blocks in active pharmaceutical ingredients. Herein, we report a rhodium precatalyst with a chiral disulfoxide ligand that effects the 1,2-addition of arylboroxines to aromatic imines to give high yields and high enantioselectivities of these products. The present paper describes a system that is very simple, where the ease of synthesis of the chiral ligand is combined with low catalyst loadings and reaction conditions that do not need any additives or external base.

A novel chiral disulfoxide ligand pair bearing fluorine atoms at the 6 and 6' position of its atropisomeric backbone, ( M, S, S)- and ( P, S, S)- p-Tol-6F-BIPHESO, was synthesized. Complexation to a rhodium(I) precursor gave rise to μ-Cl- and μ-OH-bridged rhodium dimer complexes incorporating the new ( M, S, S)- p-Tol-6F-BIPHESO ligand, while its sibling ( P, S, S)- p-Tol-6F-BIPHESO was not complexed efficiently to the rhodium precursor. The performance of this disulfoxide ligand [( M, S, S)- p-Tol-6F-BIPHESO] in catalysis was tested in both 1,4- and 1,2-addition reactions of arylboronic acids. We show that addition to both cyclic and acyclic enones as well as N-tosylarylimines proceeds with high yields and high enantioselectivities to give the corresponding products. The synthesis of enantiomerically pure p-Tol-6F-BIPHESO is straightforward and inexpensive which, together with the high catalytic performance and wide substrate scope for these addition reactions, makes it a very attractive alternative to more classical chiral ligand entities.

In this article, we present the design and construction of a series of supramolecular poly(benzyl ether) metallodendrimers featuring a well-defined hexagonal metallacycle at their cores via coordination-driven self-assembly. It was found that the second generation metallodendrimer 3c was able to hierarchically self-assemble into the regular vesicle-like structures. These nanoscale vesicles were monodisperse in shape and relatively monodisperse in size as detected in SEM, TEM, AFM, and DLS experiments. Notably, this kind of hierarchically formed vesicle-like nanostructure adopted a discrete metallacycle as the main skeleton, which is obviously different from many previous reports of nanoscale spherical architectures. Moreover, such supramolecular vesicle-like structures could encapsulate some fluorescent molecules, like BODIPY and SRB, etc. By taking advantage of the dynamic nature of metal-ligand bonds, the disassembly and reassembly of the hexagonal cavity core could be reversibly controlled by the addition and removal of bromide ions, resulting in the transition from the vesicles to micelles. Thus, the controlled release of fluorescence dye was successfully realized by the halide-induced vesicles-micelles transition. These findings not only enrich the library of supramolecular metallodenrimers but also provide a new avenue to the construction of novel "smart" nanomaterials, which have potential application in functional molecules delivery and release.

Enantiomerically pure diarylmethylamines are important building blocks in active pharmaceutical ingredients. Herein, we report a rhodium precatalyst with a chiral disulfoxide ligand that effects the 1,2-addition of arylboroxines to aromatic imines to give high yields and high enantioselectivities of these products. The present paper describes a system that is very simple, where the ease of synthesis of the chiral ligand is combined with low catalyst loadings and reaction conditions that do not need any additives or external base.

A new class of supramolecular organometallic gels with a discrete rhomboidal metallacycle as the main skeleton was fabricated through hierarchical self-assembly (see figure). More importantly, by taking advantage of the dynamic nature of metal-ligand bonds, the stimuli-responsive gel-sol transition of the obtained gels was realized by disassembly and reassembly of the rhomboidal scaffold as controlled by bromide anions.

By combining 60° bis(ferrocenyl) di-Pt(II) acceptors and the complementary 120° dipyridyl or dicarboxylate donors substituted with [G-1]–[G-3] Frechet-type dendrons, self-assembly of a new series of charged or neutral dendritic tetrakis(ferrocenyl) rhomboids was realized under mild conditions in high yields, respectively. The structures of all difunctionalized rhomboids were characterized by multinuclear NMR (1H and 31P), ESI-TOF-MS, CSI-TOF-MS, and elemental analysis. Moreover, their electrochemical behavior was studied through cyclic voltammetry investigations. Further insight into the structural characterization of all rhomboidal metallacycles, such as the shape and size, was obtained via molecular simulation by PM6 semiempirical molecular orbital methods.

A new family of 60° dendritic di-Pt(II) acceptor tectons have been successfully designed and synthesized, from which a series of novel "three-component" triangular metallodendrimers were prepared via [3 + 3] coordination-driven self-assembly. The structures of newly designed triangular metallodendrimers are characterized by multinuclear NMR ((1)H and (31)P), (1)H DOSY NMR, mass spectrometry (CSI-TOF-MS), and elemental analysis. The shape and size of all supramolecular dendritic triangles were investigated with PM6 semiempirical molecular orbital methods.

By combining rigid 120° dicarboxylate donors substituted with [G-0]–[G-3] Frechet-type dendrons and complementary 120° ferrocenyl di-Pt(II) acceptors, a new family of neutral dendritic multiferrocenyl hexagons have been successfully prepared under mild conditions in high yields.

A novel family of hexakis(ferrocenyl) triangles has been successfully constructed from newly designed 60° ferrocenyl building blocks via coordination-driven self-assembly. The structures of all triangles were characterized by multinuclear NMR (1H and 31P), ESI-TOF-MS, and elemental analysis, and their electrochemical behavior has been investigated.

The design and synthesis of a new class of dendritic multiferrocenyl hexagons have been achieved via [3+3] coordination-driven self-assembly. The relative distribution of dendritic and ferrocenyl subunits on the periphery of supramolecular metallocycles can be precisely controlled. The structures of all compounds are confirmed by multinuclear NMR, ESI-MS/ESI-TOF-MS, and elemental analysis. The electrochemical properties of the newly designed dendritic multiferrocenyl complexes have been studied through cyclic voltammetry investigation.

We demonstrated an erbium-doped mode-locked fiber laser using a single-walled carbon nanotube-dispersed polyimide (SWNT-PI) film. Different mode-locking operations were compared and analyzed utilizing SWNT-PI films with different concentrations (2, 1, and 0.25 wt.%, respectively). It was found that the continuous single-pulse mode-locking operation was often accompanied by a continuous wave oscillation part for the 1 and 0.25 wt.% SWNT-PI films, whereas the 2 wt.% SWNT-PI film presented the most excellent mode-locking performance, thanks to sufficient modulation depth. Using the 2 wt.% SWNT-PI film, a stable pulse train with a pulse width of 840 fs and a repetition rate of 15.3 MHz was achieved. The average output power was 0.33 mW at the pump power of 155 mW under an output coupling ratio of 10%. Operational performance of the laser cavity when employing the 2 wt.% SWNT-PI film was also demonstrated.

An environmentally stable, repetition rate tunable, all-polarization-maintaining, Er-doped pulse fiber laser with a single-wall carbon nanotubes saturated absorber is demonstrated. The ring laser cavity includes a delay line enabling a tunable repetition rate to vary from 35.52 MHz to 35.64 MHz with continuous mode-locked operation. The laser output parameters confirm that the tunable mode-locked operations are stable. High environmental stability is also confirmed by the −130 dBc/Hz low phase noise, a 70-dB signal-to-noise ratio of radio frequency signals, a low amplitude fluctuation of 5.76 × 10−4, and a low fluctuation of repetition rate of 12 Hz. The laser shows a high degree of polarization of 93%.

Transitional operations of multiple dissipative solitons in a long-cavity normal-dispersion Yb-doped fiber laser are experimentally investigated. Multiple dissipative solitons, including a stable soliton pair and a soliton triplet are observed by increasing the pump power or adjusting the polarization controllers. Two main boundaries of the stable asymmetric soliton and oscillating soliton are found between steady mode-locking. Moreover, multiple dissipative solitons with greater quantities of solitons are observed with pump power increasing. The experimental results agree well with a previous numerical study of multiple dissipative solitons.