Crystal structures and spectroscopic properties of a new zinc phosphite cluster and an unexpected chainlike zinc phosphate obtained by hydrothermal reactions

A new zinc phosphite cluster, Zn₂(4,4′-dmbpy)₂(H₂PO₃)₄1, and a new chainlike zinc phosphate, Zn₂(5,5′-dmbpy)₂(HPO₄)(H₂PO₄)₂2, have been synthesized under hydrothermal conditions (4,4′-dmbpy=4,4′-dimethyl-2,2′-dipyridy, 5,5′-dmbpy=5,5′-dimethyl-2,2′-dipyridy). Compound 1 is a molecular zinc phosphite constructed from ZnO₃N₂ trigonal bipyramids, H₂PO₃ pseudo-pyramids and 4,4′-dmbpy ligands. Compound 2 possesses a 1D chainlike framework constructed from ZnO₃N₂ trigonal bipyramids, HPO₄ tetrahedra, H₂PO₄ tetrahedra and 5,5′-dmbpy ligands. Both compounds 1 and 2 exhibit intensive photoluminescence originated from the intraligand π-π* transitions. Crystal data: 1, monoclinic, P2₁/n, , , , β=110.857(3)°, , Z=2, R1=0.0297, wR₁=0.0801; 2, triclinic, P-1, , , , α=64.995(9)°, β=65.952(9)°, γ=65.296(8)°, , Z=2, R₁=0.0418, wR₁=0.1010.     

Disorder in condensed matter systems: proton spin lattice relaxation study of the mixed systems of betaine phosphate and glycine phosphite, BPxGPI(1-x)

Proton NMR relaxation measurements have been carried out in the mixed system of antiferroelectric (AFE) betaine phosphate (BP) and ferroelectric (FE) glycine phosphite (GPI), BPxGPI(1-x), at 11.4 and 23.3 MHz from 300 to 100 K for x=0.3, 0.4, 0.5, 0.6, 0.7 and 0.8. The temperature dependence of spin lattice relaxation (SLR) time follows the BPP model in the parent compounds, while the Larmor frequency dependence of T1 in the mixed system is rather unusual. The T1 curve exhibits different slopes for the low-temperature wings at the two frequencies, which is a clear experimental evidence of the presence of different methyl groups with different activation energies (Ea), indicating disorder. For x=0.3 and 0.4, biexponential recovery of magnetization has been observed below 190 K, showing that the degree of disorder varies with the concentration. The temperature dependence of relaxation time data has been interpreted in terms of NH3, trimethyl ammonium and methyl group reorientations.     

An efficient multi-component synthesis of (2-amino-3-cyano-4H-chromen-4-yl) phosphonic acid diethyl ester

(2-Amino-3-cyano-4H-chromen-4-yl) phosphonic acid diethyl esters are prepared via a single-step multi-component reaction of structurally diverse salicylaldehydes with malononitrile and triethyl phosphite using a catalytic amount of potassium phosphate in ethanol at ambient temperature. Use of potassium phosphate as an inexpensive catalyst makes the protocol more economical. Mild reaction conditions, simple work-up procedure are the added advantages of the present method.     

新型氮磷阻燃剂的合成及表征

以甲醛溶液、尿素、亚磷酸三甲酯为原料合成了N,N'-二甲基磷酰基脲,确定了最适加料方式、投料比例、反应温度及反应时间等条件.并通过红外光谱,1H NMR等对该化合物进行结构鉴定.在热重分析中该化合物显示出优异的热稳定性和较好的成炭性,可作为阻燃剂使用.     

碘化亚铜/亚磷酸三乙酯催化碘代芳烃和末端炔烃的偶联反应

以廉价的亚磷酸三乙酯为配体,首次用于Cu催化的碘代芳烃和末端炔烃的偶联反应,考察了不同Cu盐、金属纯度、碱和催化剂用量等条件对反应性能的影响.结果表明,当以高纯度的CuI (99.999％)为铜源,催化剂用量为5mol％时,在KOH作用下,该催化体系成功催化了一系列碘代芳烃和末端炔烃的反应,表现出良好的催化活性,此外,...     

Convenient one-pot procedure for synthesizing 4,4′-dimethoxy-boradiaza-s-indacene dyes and their application to cell labeling

We succeeded in developing a convenient one-pot pathway for synthesizing 4,4′-dimethoxy-boradiaza-s-indacene dyes 4a-d. The structures feature two methoxy groups in place of the fluorine atoms in 4,4′-difluoro-4-boradiaza-s-indacene. These novel dyes emitted green fluorescence and possessed moderate to high fluorescence quantum yields (Φ=0.32-0.93). We demonstrated that these dyes have applicability to cell labeling.     

Nickel-catalyzed Arbuzov reactions of aryl triflates with triethyl phosphite

An efficient method was developed for the nickel-catalyzed phosphonylation of aryl triflates with triethyl phosphite, in which KBr as an additive promoted the S_N2 catalytic step. To the best of our knowledge, this is the first example of nickel-catalyzed Arbuzov reactions of aryl triflates. Most of the substrates showed good reactivity under this catalytic system.     

溴化钯或乙酰丙酮羰基铑/手性配体催化醛与乙酰胺的不对称酰胺羰化反应研究

采用溴化钯为催化剂前体,与非螯合型双齿膦配体L1(DPPFF)、联吡啶型双齿膦配体L2(P-PHOS)和二茂铁基手性双膦配体L3((S,Rp)-BPPF)制备络合物催化剂,以乙酰丙酮羰基铑为催化剂前体,与手性亚磷酸酯配体L4-L6制备络合物催化剂,将其分别应用于底物环己基甲醛或苯乙醛的不对称酰胺羰化反应中,研究结果表明...     

NMR relaxation study of disorder in condensed matter – low temperature studies in the mixed system − BPI(1−x)BP x – transition from classical to quantum rotation

¹H NMR spin-lattice relaxation time (T₁ ) studies have been carried out in the mixed system, betaine phosphite–betaine phosphate (BPI_(1?x)BP _x ), to study the effects of disorder. The T₁ data in the temperature range 100 K to 4 K, at two Larmor frequencies 11.4 and 23.3 MHz, has been analysed following Lourens’ model, which shows a gradual transition from classical reorientations to quantum tunnelling motions. At lower temperatures, (when thermal motions become too slow) differences (due to disorder) in the local environments of the reorienting groups result in a distribution in the activation energy (E_a ) and the energy gap of the ground to the first excited torsional level (E₀₁ ). Below 50 K, the system moves into the quantum tunneling regime and the magnetisation recovery shows biexponential behaviour which is another signature of disorder. These results are compared with those of the parent compounds BP and BPI.     

FTIR跟踪研究不饱和氯代阻燃聚醚多元醇与亚磷酸酯阻燃剂的反应

采用FTIR技术跟踪研究了由乙二醇和环氧氯丙烷以及烯丙基缩水甘油醚共聚而成的不饱和氯代聚醚多元醇,与亚磷酸三甲酯发生酯交换反应和酯交换聚合反应以及Arbuzov重排反应过程,合成反应型聚醚多元醇亚磷酸酯阻燃剂的方法。实验考察了物质量配比、反应温度、投料方式等对上述反应进程的影响。分析结果表明反应温度是决定上述反应进程的关键因素,同时适当条件下合成的反应产物,可以用作一种光固化的兼有抗老化和增塑功能新型有机磷酸酯阻燃剂。