Chung Yuan Christian University

About: Chung Yuan Christian University is a education organization based out in Taoyuan City, Taiwan. It is known for research contribution in the topics: Membrane & Fuzzy logic. The organization has 9819 authors who have published 11623 publications receiving 213139 citations. The organization is also known as: Tiong-gôan-tāi-ha̍k & CYCU.

Ligand isomerism-controlled structural diversity of cadmium(II) perchlorate coordination polymers containing dipyridyladipoamide ligands

Abstract: The syntheses, structures and ligand conformations of three Cd(II) coordination polymers [Cd(L1)(ClO4)2]∞ [L1 = N,N′-di(2-pyridyl)adipoamide], 1, {[Cd(L2)2(CH3OH)2](ClO4)2·2CH3OH}∞ [L2 = N,N′-di(3-pyridyl)adipoamide], 2 and [Cd(L3)2(ClO4)2(CH3CH2OH)2]∞ [L3 = N,N′-di(4-pyridyl)adipoamide], 3, are reported. Their structures have been characterized by X-ray crystallography. Complex 1 forms 1D zigzag chains, while complex 2 forms 2D pleated sheets which are positioned in an ABAB manner. Complex 3 shows a rare 3D entanglement from parallel polycatenation of 3-fold interpenetrated square layers. While the L1 ligands in 1 adopt AAAtrans conformations and the L2 ligands in 2 adopt GAGtrans conformations, the L3 ligands in 3 adopt AAAtrans and AGAtrans conformations. The structural types of the Cd(II) coordination polymers can be directed by ligand isomerism.

Tridentate anilido-aldimine magnesium and zinc complexes as efficient catalysts for ring-opening polymerization of ε-caprolactone and L-lactide

Abstract: A novel tridentate anilido-aldimine ligand, [o-C6H4(NHAr)HCNCH2CH2NMe2] (Ar = 2,6-iPr2C6H3, L-H, 1), has been prepared by the condensation of N, N-dimethylethylenediamine with one molar equivalent of 2-fluoro-benzaldehyde in hexane, followed by the addition of the lithium salt of diisopropylaniline in THF. Magnesium (Mg) and zinc (Zn) complexes supported by the tridentate anilido-aldimine ligand have been synthesized and structurally characterized. Reaction of L-H (1) with an equivalent amount of MgnBu2 or ZnEt2 produces the monomeric complex [LMgnBu] (2) or [LZnEt] (3), respectively. Experimental results show that complexes 2 and 3 are efficient catalysts for ring-opening polymerization of e-caprolactone (CL) and L-lactide (LA) in the presence of benzyl alcohol and catalyze the polymerization of e-CL and L-LA in a controlled fashion yielding polymers with a narrow polydispersity index. In both polymerizations, the activity of Mg complex 2 is higher than that of Zn complex 3, which is probably due to the higher Lewis acidity and better oxophilic nature of Mg2+ metal. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4927–4936, 2009

Modification of a neural network utilizing hybrid filters for the compensation of thermal deformation in machine tools

Abstract: This study proposes a modified method that combines feed-forward neural network (FNN) and hybrid filters to improve the accuracy and reduce computation times for the prediction of thermal deformation in a machine tool. The hybrid filter consists of the linear regression (LR), moving average (MA) and autoregression (AR). Their outputs serve as input of FNN, which are estimated by the static and dynamic relationships between the temperature distributions and thermal deformations. This modified method enables the propagation accuracy between input and output layers of a static FNN to be improved and the learning time to be reduced. Furthermore, the modified method is compared with other three ones, which are traditional ARMA, FNN, and FNN combined with LR by numerical analysis and practical experiments. In analysis, the error margins of various approaches are compared using a finite element model that is determined for the relationships between thermal deformation and temperature distribution. Also, practical experiments of these approaches for a grinding machine are realized to compare the deformation predications according to temperature measurements.

Zinc and magnesium complexes incorporated by bis(amine) benzotriazole phenoxide ligand: Synthesis, characterization, photoluminescent properties and catalysis for ring-opening polymerization of lactide

Abstract: A new bis(amine) benzotriazole phenoxide ligand, C8NNBTP-H (1) was prepared from the Mannich condensation of 2-(2H-benzotriazol-2-yl)-4-(2,4,4-trimethylpentan-2-yl)phenol with the mixtures of excess paraformaldehyde and N,N,N-trimethylethylenediamine under reflux conditions. Zinc and magnesium complexes bearing the N,N,O-tridentate C8NNBTP ligand were synthesized and fully characterized. The reaction of C8NNBTP-H with ZnEt2 (1.2 molar equiv.) in toluene gives the monomeric tetra-coordinated zinc complex [(C8NNBTP)ZnEt] (2). The homoleptic and monomeric complexes [(C8NNBTP)2M] (M = Zn (3) and M = Mg (4)) result from treatment of ZnEt2 or MgnBu2 with C8NNBTP-H (two equiv.), in which the metal center is hexa-coordinated by two tridentate C8NNBTP ligands. Luminescent properties and catalysis for lactide (LA) polymerizations of complexes 2–4 are studied. Complexes 2–4 produce bright green fluorescence with emission maxima ranging from 510 to 520 nm in the solid state. Experimental results indicate that complex 2 catalyzes the ring-opening polymerization of LA in the presence of 9-anthracenemethanol (9-AnOH) with efficient catalytic activities in a controlled fashion, yielding poly(rac-lactide) with a slight isotactic predominance (Pm = 0.59).