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161.
The ENDOR spectrum of ~(14)N-~(63)Cu-HAP complex in DMSO/EtOH (5:1) freezing solution at 20 K has been studied using orientational selective method in this paper. The anisotropic superhyperfine coupling tensor and qusdrupole coupling tensor of ligand ~(14)N nucleus, and the superhyperfine coupling tensor of various ~1H nuclei have been measured precisely. Comparing the superhyperfine coupling tensor of ~(14)N-nucleus with previous work shows that the analytical method of spectrum is reasonable and the data are reliable in our previous work. 相似文献
162.
Four chiral polymers P-1, P-2, P-3 and P-4 were synthesized by the polymerization of (S)-2,2'-dioctoxy-1,1'- binaphthyl-6,6'-boronic acid (S-M-3) with (S)-6,6'-dibromo-1,1'-binaphthol (S-M-1), (R)-6,6'-dibromo-1,1'- binaphthol (R-M-1), (S)-3,3'-diiodo-1,1'-binaphthol (S-M-2) and (R)-3,3'-diiodo-1,1'-binaphthol (R-M-2) under Pd-catalyzed Suzuki reaction, respectively. All four polymers can show good solubility in some common solvents due to the nonplanarity of the polymers in the main chain backbone and flexible alkyl groups in the side chain. The analysis results indicate that specific rotation and circular dichroism (CD) spectral signals of the alternative S-S chiral polymers P-1 and P-3 are larger than those of S-R chiral polymers P-2 and P-4, but their UV-Vis and fluorescence spectra are almost similar. The results of asymmetric enantioselectivity of four polymers for diethylzinc addition to benzaldehyde indicate that catalytically active center is (R) or (S)-1, 1'-binaphthol moieties. 相似文献
163.
The synthesis and crystal structure of Li3AlB2O6 with different cell parameters are reported and these cells are transformed each other from the confirmation of crystallographic structural analyses. The absorption spectrum, luminescence and lifetimes of the Li3AlB2O6 and LiSrBO3 solid compounds are measured and the comparisons are made between them. It is shown that the absorption edges are at about 400 nm (or band gap 3.1 eV) and there is one of absorption peaks at about 350 nm for the Li3AlB2O6 and LiSrBO3. The emission band (530 nm) makes a red shift and fluorescence decay time (24.39 ns) of the Li3AlB2O6 becomes smaller compared with the emission band (480 nm) and lifetime (93.16 ns) of the LiSrBO3 at the visible region. The transition energies and oscillator strengths of the clusters (Li3AlB2O6)2 and (LiSrBO3)2 lying at low excited states are calculated by the time-dependent Hartree-Fock method. The obtained results are used to model the photophysical properties and discuss the origin of spectral bands of the Li3AlB2O6 and LiSrBO3. 相似文献
164.
催化增强化学蒸气沉积法在聚酰亚胺上沉积钯-铂合金薄层 总被引:4,自引:0,他引:4
以N2,O2作载气,通过催化增强化学蒸气沉积(CECVD)分别制得在聚酰亚胺上的金属铂、钯及其合金薄层。铂、钯配合物的共同沉积可生成Pt-Pd合金薄膜。在Pd-Pt合金的沉积过程中,Pd/Pt的原子数比率随共同沉积的条件改变而变化。O2为载气、300 ℃条件下,用Pd(η3-allyl)(hfac)和Pt(COD)Me2作前驱体共沉积制备Pd-Pt合金,得到含Pd 37.2%,Pt 62.8%且不 相似文献
165.
利用水和乙醇混合溶剂合成了稀土三氯醋酸盐与2份1,10-邻菲绕啉(phen)配合物RE(CCl_3COO)_3(phen)_2·nH_2O(RE=Nd,Sm,n=0;RE=Eu,n=2)的单晶.结构测定表明,Nd(CCl_3COO)_3(phen)_2为三斜晶系,每个三氯醋酸盐均以双齿配位,2个phen亦为双齿配位,故配位单元中钕为10配位;Eu(CCl_3COO)_3(phen)_2·2H_2O为单斜晶系,1个三氯醋酸根在外界,2个三氯醋酸根为单齿配位,2个phen为双齿配位,另有2分配位水,故配位单元中Eu为8配位. 相似文献
166.
气相渗透法中的溶质吸附效应 总被引:1,自引:0,他引:1
在气相渗透仪上,用四个低分子量有机化合物和五个已知平均分子量的窄分布聚苯乙烯低聚体,对VPO方法中的溶质吸附效应作了研究,提出了一种对吸附效应作改正的方法.所得结果表明,在扣除溶质吸附效应后,仪器常数K无分子量依赖性,提高了测定低分子量聚合物数均分子量的准确性. 相似文献
167.
Four dithiooxalato (Dto) bridged one-dimensional Ni(ll) and Ni(ll)Cu(ll) complexes (Me6[14]dieneN4)Ni2(Dto)2) (1), (Me6[14]dieneN4)CuNi(Dto)2 (2), (Me6[14]aneN4)Ni2(Dto)2 (3), and (Me6[14]aneN4)CuNi(Dto)2(4), were synthesized. These complexes have been characterized by elemental analysis, IR, UV and ESR spectra. The crystal structure of complex 3 was determined. It crystallizes in the monoclinic system, space group C2/c with a = 2.2425(4) nm, b = 1.0088(2) nm, c=1.4665(3) nm, β= 125.32(3)° ;Z=4; R = 0.076, Rw = 0.079. In the complex, Ni(1) coordinates four sulphur atoms of two Dto ligands in plane square environment. Ni(2) lies in the center of mac-rocyclic ligand. For Dto ligand, two sulphur atoms coordinate Ni(1), and O(1) coordinates Ni(2) and forms weak coordination bond. O(2) is linked to N(2) of macrocyclic ligand through hydrogen bond. 相似文献
168.
Precursor molecule (R)-6,6′-bis(triethoxysilylethen-2-yl)-2,2′-di(methoxyethoxymethyloxy)-1,1′-binaphthyl (R-2) was synthesized by Pd-catalyzed Heck reaction of (R)-6,6′-dibromo-2,2′-di(methoxyethoxymethyloxy)-1,1′-binaphthyl (R-1) intermediate with vinyltriethoxysilane. The hydrolysis and polycondensation of the precursor R-2 produced the corresponding xerogel. Both precursor and xerogel were analysed by NMR, FTIR, UV, CD spectra, fluorescent spectroscopy, polarimetry and elemental analysis. The precursor and xerogel can emit strong blue fluorescence and are expected to have a potential application in the separation of chiral molecules as fluorescent sensor. The precursor exhibits strong Cotton effect in its circular dichroism (CD) spectrum indicating a highly rigid structure. 相似文献
169.
CHENG Peng YAN Shi-Ping LIAO Dai-Zheng BAI Ling-Jun JIANG Zong-Hui WANG Geng-LinDepartment of Chemistry Nankai Uviversity Tianjin China 《中国化学》1994,12(4):314-320
The syntheses and magnetic properties are reported for a series of copper(Ⅱ) complexes prepared from a pentadentate binucleating ligand 2,6-diformyl-4-methylphenol di(benzoyl-hydrazone) (H3L). These complexes incorporate different exogenous ions (X-) into a bridging position to form copper(Ⅱ) binuclear complexes of the formula [Cu2(H2L)X]2+, where X-= Br-(1), Cl-(2), HO-(3), C2H5O-(4) and C3H3N2- (5). The complexes have been characterized with variable temperature magnetic susceptibility (4.2-300 K) and the observed data were fit to those from a modified Bleaney-Bowers equation by least-squares method, giving the exchange integral 2J = -6.2 cm-1 for 1, -76.4 cm-1 for 2, -241.9 cm-1 for 3, -231.1 cm-1 for 4 and -343.8 cm-1 for 5. This suggested that there is an antiferromagnetic interaction between the Cu(Ⅱ) ions and the sequence of the effect of some exogenous bridging ligands on magnetic coupling is corresponding to that in spectrochemical series. 相似文献
170.
The states of water in poly (N-vinylpyrrolidone-methylmethacrylate) and poly (N-vinylpyrroli-done-2-hydroxyethyl methacrylate) hydrogels have been studied by means of DSC. The effect ofpolmer structure on equilibrium swelling extent of water has been examined. It was found that thestate of water and the water content in different hydrogels were dependent on the kind of monomer used,the component of copolymer, the sequence distribution of the monomer unit and the degree of cross-linking (including chemical and physical) to a great extent. The equilibrium water content of thehydrogel may be regarded as the sum of the different state of swollen water contents of the hydrogel.Based on these, a semiempirical formula used to estimate the equilibrium water content of the copolymerhydrogels was presented. 相似文献