Publications by authors named "Yu-Xin Peng"

In this study, the Beta regression models of sapwood, heartwood, and bark density of Larix olgensis were constructed. A total of 35 trees were destructively sampled from plantations in three different sites, Linkou Forestry Bureau of Heilongjiang Province, Dongjingcheng Forestry Bureau, and Maoershan Experimental Forest Farm of Northeast Forestry University. AIC, R, BIAS, RMSE and LRT were used as the goodness-of-fit statistics to compare and select the most optimal models for sapwood, heartwood, and bark density.

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A novel mesoporous nanosphere functionalized with 3-(aminopropyl)triethoxysilane (APTES) and 2-(5-bromothiophen)imidazo[4,5-f][1,10]phenanthroline (5-Br-Tip) was synthesized (denoted as Tip-MSS). With the coordinating function of the 5-Br-Tip to lanthanide (Ln) ions, for the first time, LnL3(5-Br-Tip) complexes were linked to the mesoporous nanospheres. The derived materials, named Ln-Tip-MSS (Ln = Eu, Tb, Sm, Nd, Yb), were characterized by Fourier-transform infrared (FT-IR) spectroscopy, TEM, XRD (wide-angle and small-angle), N2 adsorption/desorption analysis, and fluorescence spectroscopy.

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A pair of isomeric ruthenium sensitizers BM1 and BM2, having TIP based ancillary ligands with a 9-phenylcarbazole tail at the α or β position of the thiophene unit, shows a distinguishable photovoltaic performance on DSCs (PCEs: 7.33% and 5.33% for BM1 and BM2 as compared with 6.

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A family of planar oligothiophene/imidazole/1,10-phenanthroline (OTIP)-based heterocyclic, aromatic, semiconducting, and fluorescent compounds with N-substituted alkyl chains (allyl, n-butyl, n-octyl, n-dodecyl, and n-cetyl) have been designed and synthesized. They all have specific N-coordination sites, various donor-acceptor spacers, good molecular planarity, suitable solubility, and high thermal stability. In comparison with conventional double β-alkylation of the thiophene ring, our results reveal that the single imidazole N-alkylation strategy for OTIPs has the advantage of maintaining the planarity of the whole molecule, in addition to improving the solubility, which can be clearly verified by the small dihedral angles between adjacent thiophene/imidazole/1,10-phenanthroline (TIP) rings in eight X-ray single-crystal structures.

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A dinuclear Cu(ii) complex [Cu2(L3)2]·2H2O, having an unprecedented in situ formed diphenolate 2,6-piperidin-4-one derived ligand produced from the flexible Schiff-base ligand HL1, can be yielded as a side product in the presence of Cu(OAc)2·H2O-NH3·H2O dissolved in methanol and acetone in addition to the expected dinuclear Cu(ii) complex [Cu2(L1)4].

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A series of T- and H-shaped donor-acceptor (D-A) types of dipyrido[3,2-a:2',3'-c]phenazine (DPPZ)-based molecules, extended by thienyl and triphenylamino chromophores at the 2,7-(bottom) and/or 10,13-positions (top), have been designed and prepared successfully. Synthetic, structural, thermal, spectral, and computational comparisons have been carried out for related compounds because of their adjustable intramolecular charge-transfer properties. It is noted that a pair of structural isomers (5 and 6) has been obtained, respectively, where distinguishable UV/Vis and fluorescence spectra, electrochemical activity, thermal stability, and bandgaps are observed.

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A family of linear asymmetrical D-π-A and symmetrical D-π-D types of thiazole-based aromatic heterocyclic fluorescent compounds bearing various electron-donating and electron-withdrawing tails (bromo, triphenylamino, pyridyl, thienyl and benzoic acid) have been designed and prepared successfully. Synthetic, structural, thermal, spectral and computational comparisons have been carried out for related compounds because of their adjustable electronic properties. It is interesting to mention that compound 2 can be prepared from 5-bromothiazole by one-pot Suzuki-Miyaura coupling and subsequent C-H activation reactions via a 5-TPA-substituted thiazole intermediate 1.

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A family of stable and soluble bithiazole-centered heterocyclic aromatic fluorescent compounds is described herein. All these multiple N-donor containing compounds have effective π-conjugated systems and different imidazole, pyridine, thiophene, triphenylamino, benzoic acid, and ethyl benzoate tails showing distinguishable D-A-A-D and A-A-A-A structures. X-ray single-crystal structures of seven compounds indicate that all of the bithiazole cores have the same trans coplanar configuration but exhibit different dihedral angles with their adjacent aromatic heterocycles (4.

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Article Synopsis
  • * pH-titration experiments show that while there is a balance between the tautomers in solution, the hydrazone form prevails under standard conditions; this is backed by (1)H NMR results showing the presence of the hydrazone proton.
  • * A novel dinuclear dye-metal complex was formed, where all ligands exist in the azo form, with distinct coordination roles observed among the ligands linking
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