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Two diynes bearing functional groups with different binding modes, 3,6-diethynylpyrazine (HL1) and 3,8-diethynyl-1,10-phenanthroline (HL2), were utilized as ligands to synthesize two new organometallic units, AgL1·3AgNO (1) and AgL2·6AgNO (2), in order to investigate the effect of the bridging and chelating modes of the ligands on the structures of networks constructed from silver-ethynide compounds. Structural studies show that in 1, silver-ethynide cluster units aggregate to form chair-like organometallic slides through Ag-N coordination bonds. These slides are linked through argentophilic interaction to generate novel 2D ladder-like layers, and are further bridged by nitrate anions to afford a 3D network in the solid state. It is observed that all the Ag ions in one layer interact to afford a 2D silver network. However, in 2, the silver-ethynide cluster units only interact to generate unique sine wave-like organometallic chains through argentophilic interaction, which are further connected by nitrate anions to form a 3D network. In the solid state, both 1 and 2 are luminescent at room temperature.

A reaction of 6,6'-bis((benzylthio)methyl)-2,2'-bipyridine (L) with CuI at room temperature led to one Cu4I4-based cluster, which could be thermally transferred to Cu2I2-based one under mild condition due to the formation...

By adopting the absolute nodal coordinate formulation, a novel and general nonlinear theoretical model, which can be applied to solve the dynamics of combined straight-curved fluid-conveying pipes with arbitrary initially configurations and any boundary conditions, is developed in the current study. Based on this established model, the nonlinear behaviors of the cantilevered L-shaped pipe conveying fluid with and without base excitations are systematically investigated. Before starting the research, the developed theoretical model is verified by performing three validation examples. Then, with the aid of this model, the static deformations, linear stability, and nonlinear self-excited vibrations of the L-shaped pipe without the base excitation are determined. It is found that the cantilevered L-shaped pipe suffers from the static deformations when the flow velocity is subcritical, and will undergo the limit-cycle motions as the flow velocity exceeds the critical value. Subsequently, the nonlinear forced vibrations of the pipe with a base excitation are explored. It is indicated that the period-n, quasi-periodic and chaotic responses can be detected for the L-shaped pipe, which has a strong relationship with the flow velocity, excitation amplitude and frequency.

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