Yong Nie

Substitution degree engineering the crystal packing and optoelectronic properties of benzofuranvinyl-substituted benzene-cored derivatives

In order to explore new furan-based functional materials, investigate the effect of the degree of branching on their optoelectronic properties and search for three-dimensional organic semiconductors from planar π-conjugated molecules, the compounds 1,4-bis[2-(benzofuran-2-yl)vinyl]benzene (2BFVB) with a linear shape, 1,3,5-tris[2-(benzofuran-2-yl)vinyl]benzene (3BFVB) with a star shape and 1,2,4,5-tetra[2-(benzofuran-2-yl)vinyl]benzene (4BFVB) with a cruciform shape were synthesized and compared. 2BFVB adopts a two-dimensional herringbone packing motif and there are two kinds of molecular conformation. The crystal packing of 3BFVB is more sensitive to the crystallization conditions. Two single-crystal phases and one thin-film phase were found. 3BFVB (β-phase) molecules pack into a three-dimensional cofacial herringbone structure. 4BFVB forms an inter-inserted two-dimensional hexagonal packing structure. The molecular shape and aggregate packing exert remarkable effects on the optoelectronic properties. The quantum yield of 2BFVB is very high both in the solution (74%) and in the crystalline solid (76%) states. The high solid emission efficiency of 2BFVB is possibly related to the two molecular conformations in the herringbone-arranged H-aggregates. Both 2BFVB and 3BFVB display hole-transport abilities. The performance of 3BFVB amorphous film is nearly equal to that of its crystalline film, which would be helpful in simplifying device fabrication. This study shows that the substitution degree exerts drastic effects on solubility, polymorphism, crystal packing and optoelectronic properties.

A fast-response, fluorescent 'turn-on' chemosensor for selective detection of Cr3+

A fast-response, highly selective and sensitive chemosensor, 3, for Cr3+ detection with turn-on fluorescence behavior in the physiological pH range was designed and synthesized. The chemosensor contained a combined push–pull system in which the fluorescent phenanthro[9,10-d]oxazole moiety acts as both an electron donor and a potential binding site. The electron deficient nitrile group served as an electron acceptor. A significant enhancement of fluorescence emission intensities was observed with increasing Cr3+ concentration upon excitation at 300 nm. The emission intensity reached its maximum on adding 8 equiv. of Cr3+ where the quantum yield of 3-Cr3+ was found to be 0.917, ca. 7-fold larger than chemosensor 3. The selectivity mechanism of 3 for Cr3+ was found to be based on the combined effects of the inhibition of ICT and CHEF. Remarkably the entire process was virtually complete in only 10 seconds, with a minimum detection limit for Cr3+ of 1.72 × 10−8 M−1.

Conformation twisting induced orientational disorder, polymorphism and solid-state emission properties of 1-(9-anthryl)-2-(1-naphthyl)ethylene

Polymorphism is important to study the structure–property relationship with a minimum number of variables. Compound 1-(9-anthryl)-2-(1-naphthyl)ethylene (ANE) can form three polymorphs by controlling the crystallization conditions, which belong to the P212121 space group for ANE-a, P21/c space group for ANE-b and P space group for ANE-c, respectively. Orientational disorder was found in ANE-b and ANE-c polymorphs. The emission maximum of the three polymorphs are 496, 470 and 490 nm, respectively. Each is blue-shifted from that of a concentrated solution. The formation of orientational disorder and the blue-shift behavior in emission are closely related to the degree of conformational twisting. A large dihedral angle between the anthracene and naphthalene rings is helpful to induce orientational disorder and blue-shift in the solid emission maximum. The emission efficiency of ANE solution and polymorphs is 42% (CH2Cl2 solution), 28% (ANE-a), 22% (ANE-b) and 47% (ANE-c), respectively. The ANE-c polymorph emits even more efficiently than the solution. This is attributed to the different packing environments, which produce distinct PL decay dynamics. For the three polymorphs, the decay behaviors are all double-exponential and the fluorescence efficiency is enhanced as the proportion of the short-lived component increases. This study shows that compound ANE is a kind of tunable solid-state fluorescent material and the molecular conformation plays an important role in the orientational disorder, aggregate packing and solid-state emission.

cis-Dichloridobis(triphenyl­phosphine-κP)platinum(II) chloro­form solvate

In the title compound, [PtCl2(C18H15P)2]·CHCl3, each PtII centre adopts a nearly square-planar coordination geometry formed by two P atoms [Pt—P = 2.2481 (17) and 2.2658 (19) Å] and two Cl anions [Pt—Cl = 2.3244 (19) and 2.3548 (17) Å]. The Cl atoms of the chloroform solvent molecule are disordered over two orientations in a 0.778 (11):0.222 (11) ratio. The crystal packing is stabilized by weak intermolecular C—H⋯Cl hydrogen bonds, exhibiting voids with a volume of 215 Å3.

Synthesis and Crystal Structure of the Triple-decker Complex [(η5-C5Me5)- Ru(μ,η5-1,3-C3B2Me5)RhCl- (Ph2PCH2)2]

The dimer [(η5-C5Me5)Ru(C3B2Me5)RhCl]2 (2) reacts with 1,2-bis(diphenylphosphino)ethane (dppe) to give the triple-decker complex [(η5-C5Me5)Ru(C3B2Me5)Rh- (dppe)Cl] (3). Its constitution follows from NMR and MS data, and a single-crystal X-ray diffraction study. Graphical Abstract Synthesis and Crystal Structure of the Triple-decker Complex [(η5-C5Me5)- Ru(μ,η5-1,3-C3B2Me5)RhCl- (Ph2PCH2)2]

3-Carboxy­methyl-1,3-benzimidazolium-1-acetate monohydrate

The title compound, C11H10N2O4·H2O, has a zwitterionic structure, in which the benzimidazole ring system is planar, with a maximum deviation of 0.007 (3) Å. The carboxyl/carboxylate groups adopt a trans configuration. In the crystal structure, intermolecular O—H⋯O hydrogen bonds involving the hydroxy/oxide O atoms link the molecules into a one-dimensional chain. These chains are further linked by O—H⋯O hydrogen bonds involving the water molecules into a two-dimensional network. π–π contacts between the benzimidazole rings [centroid–centroid distance = 3.5716 (4) Å] lead to the formation of a three-dimensional supramolecular structure.

1,3-Bis(carboxy-meth-yl)imidazolium triiodide 1-carboxyl-atomethyl-3-carboxy-methyl-imidazolium.

In the title compound, C7H9N2O4 +·I3 −·C7H8N2O4, the two imidazolium units are hydrogen bonded through the carboxyl groups. The units are further linked via intermolecular O—H⋯O hydrogen bonding, resulting in a one-dimensional ladder-type structure. As a result, the two carboxy groups of each imidazolium unit adopt a cis configuration with respect to the imidazolium ring.

An ortho­rhom­bic polymorph of 1-[(ferrocen­yl)(hydr­oxy)meth­yl]-1,2-dicarba-closo-dodecaborane

An orthorhombic polymorph of the title compound, [Fe(C5H5)(C8H17B10O)] or C13H22B10FeO, is described here in addition to the known monoclinic polymorph [Crundwell et al. (1999 ▶). Acta Cryst. C55, IUC9900087]. The asymmetric unit contains four independent molecules with Ccage–Ccage distances of 1.636 (16)–1.700 (16) Å, and with the methylhydroxy groups disordered over two positions in each molecule [occupancy ratios 0.80 (2):0.20 (2), 0.59 (3):0.41 (3), 0.60 (2):0.40 (2) and 0.793 (17):0.207 (17)].

Bis{2-[(2-pyrid­yl)imino­meth­yl]phenolato}copper(II)

In the title compound, [Cu(C12H9N2O)2], the CuII atom lies on a crystallographic inversion center and has a nearly square-planar geometry. The CuII center coordinates to the phenolic O and azomethine N atoms of the two symmetry-related 2-[(2-pyridyl)iminomethyl]phenolate ligands. The pyridyl N atoms do not coordinate to the CuII atom but participate in intramolecular C—H⋯N hydrogen bonding. π–π stacking between the benzene rings and between the pyridyl rings [centroid–centroid distances 3.8142 (5) and 3.8142 (5) Å, respectively] links the molecules into a chain propagating parallel to [100].

Synthesis and Characterization of o-Carboranylthioether Derivatives

The reactions of the dithiolato-o-carborane salt (Et3NH)2(S2C2B10H10) (2) with alkyl halides BrCH2CH=CH2, BrCH2CH2CH2Cl and C6H5CH2Cl, afford the o-carboranyl-bisthioether derivatives 3a - c, which have been characterized by IR and NMR (1H, 13C, 11B) spectroscopy, mass spectrometry, and single-crystal X-ray diffraction (3c). The photoluminescent properties of the known compound 3c has been investigated. It exhibits a violet (chloroform solution) or blue (solid state) emission when excited with UV light. Graphical Abstract Synthesis and Characterization of o-Carboranylthioether Derivatives