Plenty of new two-dimensional materials including graphyne, graphdiyne, graphone, and graphane have been proposed and unveiled after the discovery of the “wonder material” graphene. Graphyne and graphdiyne are two-dimensional carbon allotropes of graphene with honeycomb structures. Graphone and graphane are hydrogenated derivatives of graphene. The advanced and unique properties of these new materials make them highly promising for applications in next generation nanoelectronics. Here, we briefly review their properties, including structural, mechanical, physical, and chemical properties, as well as their synthesis and applications in nanotechnology. Graphyne is better than graphene in directional electronic properties and charge carriers. With a band gap and magnetism, graphone and graphane show important applications in nanoelectronics and spintronics. Because these materials are close to graphene and will play important roles in carbon-based electronic devices, they deserve further, careful, and thorough studies for nanotechnology applications.

Two-dimensional (2-D) micro- and nano-architectures are attractive because of their unique properties. However, the formation of 2-D supramolecular highly symmetrical structures with considerable control is still a major challenge. Here we present a simple approach for the preparation of regular and homogeneous 2-D fluorescent square non-crystallization micelles with conjugated diblock copolymers PPV12-b-P2VPn through a process of dissolving–cooling–aging. The scale of the formed micelles can be controlled by the ratio of PPV/P2VP blocks and the concentration of the solution. The results reveal that the micelles of PPV12-b-P2VPn initially form 1-D structures and then grow into 2-D structures in solution, and the growth is driven by intermolecular π–π interactions with the PPV12 blocks. The formation of 2-D square micelles is induced by herringbone arrangement of the molecules, which is closely related to the presence of the branched alkyl chains attached to conjugated PPV12 cores.

To elevate the performance of polymer solar cells (PSC) processed by non‐halogenated solvents, a dissymmetric fused‐ring acceptor BTIC‐2Cl‐γCF3 with chlorine and trifluoromethyl end groups has been designed and synthesized. X‐ray crystallographic data suggests that BTIC‐2Cl‐γCF3 has a 3D network packing structure as a result of H‐ and J‐aggregations between adjacent molecules, which will strengthen its charge transport as an acceptor material. When PBDB‐TF was used as a donor, the toluene‐processed binary device realized a high power conversion efficiency (PCE) of 16.31 %, which improved to 17.12 % when PC71ThBM was added as the third component. Its efficiency of over 17 % is currently the highest among polymer solar cells processed by non‐halogenated solvents. Compared to its symmetric counterparts BTIC‐4Cl and BTIC‐CF3‐γ, the dissymmetric BTIC‐2Cl‐γCF3 integrates their merits, and has optimized the molecular aggregations with excellent storage and photo‐stability, and also extending the maximum absorption peak in film to 852 nm. The devices exhibit good transparency indicating a potential utilization in semi‐transparent building integrated photovoltaics (ST‐BIPV).

T uning and controlling the photophysical properties of luminescent materials by changing environmental factors has been intensively studied in terms of fundamental research and practical applications in the fields of sensing, memories, detection, and display devices. [1][2][3][4][5][6][7][8][9] Particularly, stimuli-responsive fluorescence switching, such as piezochromism, vapochromism, and thermo-and acid-dependent luminescence of smart luminescent materials, has received unprecedented attentions. [10][11][12][13][14][15] Piezochromic luminescence has been obtained by changing molecular packing modes of solid materials at different phases through grinding and heating treatments. [16][17][18][19][20][21] Vapochromic organic materials were designed in an effective strategy of tuning weak intermolecular interactions such as π-stacking and hydrogen bonding. 22 Thermo-and acid-dependent luminescent materials also owned pronounced molecular structures, whose conformations or frontier molecular orbital (FMO) could be affected by thermo, acid, or base. 23 However, reports on multistimuli-responsive fluorescence switching of one chromophore are quite rare, 24,25 which is due to the lack of clear guidelines for the design of molecular structure synchronously possessing all the features of different smart materials.Herein, we synthesized an electron donor-acceptor (D-A) structured compound 1 based on the following specific design principles. First, the rod-like π-conjugated framework endows this molecule with abundant aggregation modes in the solid states, and the cyano stilbene group can rotate freely, thus resulting in interesting emission properties in solution. 26 Second, the aromatic-amine group being responsive to acid stimulus may induce significant changes in photophysical properties by disrupting the D-A nature. 27,28 Finally, the cyano and bulky CF 3 groups are expected to dramatically affect the molecular packing modes by hydrogen bonding interactions. 29 In the course of exploring the effects of environmental stimulus on the luminescent properties of this fluorophore, we found that the synthesized orange-red emissive solids exhibited interesting piezochromic fluorescence by the stimuli of grinding and heating, and the ground sample showed vapochromic emission upon exposure to organic vapor at ambient conditions. The solution of this compound and its protonated sample at room temperature (298 K) or under frozen conditions (77 K) gave totally different absorption and emission properties.Compound 1 was synthesized by a Knoevenagel reaction under gentle conditions in good yield (Scheme S1, Supporting Information). A column chromatography followed by vacuum sublimation gave rise to the pure product, which was fully characterized by 1 H NMR, mass spectra, element analyses, and finally X-ray crystal analysis. Upon being excited with UV light, the obtained orange powder and crystals exhibited bright orangered fluorescence with peaks centered at 587 (Φ f = 0.15) and 599 nm (Φ f = 0.14), respectively, and it was surpris...

For structural identification of glycans, the classic collision-induced dissociation (CID) spectra are dominated by product ions that derived from glycosidic cleavages, which provide only sequence information. The peaks from cross-ring fragmentation are often absent or have very low abundances in such spectra. Electron transfer dissociation (ETD) is being applied to structural identification of carbohydrates for the first time, and results in some new and detailed information for glycan structural studies. A series of linear milk sugars was analyzed by a variety of fragmentation techniques such as MS/MS by CID and ETD, and MS3 by sequential CID/CID, CID/ETD, and ETD/CID. In CID spectra, the detected peaks were mainly generated via glycosidic cleavages. By comparison, ETD generated various types of abundant cross-ring cleavage ions. These complementary cross-ring cleavages clarified the different linkage types and branching patterns of the representative milk sugar samples. The utilization of different MS3 techniques made it possible to verify initial assignments and to detect the presence of multiple components in isobaric peaks. Fragment ion structures and pathways could be proposed to facilitate the interpretation of carbohydrate ETD spectra and the main mechanisms were investigated. ETD should contribute substantially to confident structural analysis of a wide variety of oligosaccharides.