The synthesis, characterization, thermal and optical properties of copper, nickel, and vanadyl complexes derived from azo dyes

Two, novel, tetradentate Schiff-base ligands, namely bis-5-phenylazosalicylaldehyde diethylenetriimine and bis-5-[(4-methoxyphenyl)azo]salicylaldehyde diethylenetriimine, as well as their Cu²⁺, Ni²⁺, and VO²⁺ complexes, were synthesized and characterized using elemental analysis, infrared and also UV–Visible spectroscopy, ¹HNMR and mass spectra. The thermal stability of the free ligands and the related metal complexes, as determined using differential scanning calorimetry and thermal gravimetric analysis, were found to be thermally stable upto 240–275 °C depending on the type of ligand and the central metal atom. The λ_max of the ligands and their transition metal complexes in the region 300–800 nm are discussed. The novel metal complexes offer potential for application as recording media owing to both their absorption spectra in the blue-violet light region and high thermal stability.     

微波辐射下氯代苯胺基吡咯亚胺类化合物的合成及其晶体结构

将2-乙酰基吡咯作为前驱体与取代位置不同的芳香胺:邻氯苯胺、间氯苯胺、对氯苯胺在微波辐射下反应时发现,当氯原子(钝化基团)处于苯环的间位及对位时,芳香胺与2-乙酰基吡咯可成功发生希夫碱缩合反应得到吡咯亚胺化合物Ⅰa和Ⅰb;而当氯原子处于苯环邻位时,二者不发生反应。Ⅰa和Ⅰb的结构经X射线单晶衍射,1HNMR、IR、MS和元素分析表征证实为预期化合物。X射线单晶衍射测定结果表明,Ⅰa属单斜晶系,空间群C2/C,晶体参数a=2.372 2(15)×10-9m,b=5.720(4)×10-10m,c=1.686 8(11)×10-9m,β=98.404(10)°,V=2.264(3)×10-27m3,Z=8,D c=1.283 g/cm3,R1=0.041 9,ωR2=0.119 5。Ⅰb属单斜晶系,空间群P21/C,晶胞参数a=1.332 3(3)×10-9m,b=9.802(2)×10-10m,c=9.107(2)×10-10m,β=109.212(4)°,V=1.123 1(4)×10-27m3,Z=4,D c=1.293 g/cm3,R1=0.047 2,ωR2=0.118 9。对芳香胺上钝化基团的位置对希夫碱缩合反应的影响也进行了初步探讨。     

希夫碱镍金属催化对L-丙交酯的开环聚合

该文合成了3种希夫碱镍金属催化剂:NiL1〔乙二胺缩香草醛Ni(Ⅱ)〕、NiL2〔邻苯二胺缩3,5-二叔丁基水杨醛Ni(Ⅱ)〕、NiL3(1S,2S-二苯基乙二胺缩水杨醛Ni(Ⅱ)),并用1HNMR、X-ray单晶衍射等方法对新合成的催化剂NiL3进行了表征。以NiL1为催化剂通过单因素分析,选择合适的L-LA(左旋丙交酯)本体开环聚合条件,在该聚合条件下,对比不同配体结构特点的催化剂NiL1、NiL2、NiL3的催化聚合效果,结果表明,催化剂配体结构中引入供电子基团甲氧基有利于提高催化剂活性;配体结构中在金属活性中心周围增大位阻效应有利于得到相对分子质量(简称分子量,下同)分布较窄的聚合产物。     

Schiff碱双冠醚及其多核配合物的合成和表征

合成了Schiff碱双冠醚配体N,N′-二[(4′-苯并15冠5)次甲基]三乙烯四胺(L)及其稀土—镍硝酸盐配合物Ln3Ni(NO3)11·L(Ln=La,Ce,Pr,Eu,Gd,Y).元素分析、摩尔电导、红外光谱、紫外光谱等分析结果表明:配合物的组成为Ln3Ni(NO3)11·L·nCH3CN(n=0,1),属于1∶1型大阴大阳离子缔合物.配合物中,镍离子与桥链上的四个氮原子配位,其中两个稀土离子分别与冠醚环上的氧原子及硝酸根离子配位形成大阳离子,另一稀土离子与硝酸根离子配位形成阴离子.     

一种新型链状手性Schiff碱配体的合成

以苯酚和邻甲酚为起始原料，合成了一个新型链状手性Schiff碱配体(5，5-亚甲基一双-[(R，R)-{N-(3-甲基水杨醛)-N-(3’，5’-双-叔丁基-2’-羟基苯乙酮)／-1，2-二苯乙二胺])，并对其进行表征。在邻甲酚的羟基邻位甲酰化过程中，用三乙胺代替六甲基磷酰三胺(HMPA)定位，取得了较好的效果。通过对传统的Fries重排进行研究和改进，以较高的产率合成了新的中间体(3，5-二叔丁基-2-羟基苯乙酮)。     

Supramolecular π–π assembly of a neutral [Cu(salen)] complex via the templating effect of an ionic inorganic complex Na2[Cu(mnt)2] forming a framework type material having well-defined channels

A classical ionic inorganic complex Na₂[Cu(mnt)₂] (mnt²⁻ = maleonitriledithiolate = 1,2-dicyanoethylenedithiolate), that acts as a template in assembling neutral [Cu(salen)] (salen = bis(salicylidene)ethylenediamine) complexes forming a framework type arrangement, is accommodated in the channel formed in the crystal structure of a new type of host–guest compound [Cu(salen)]₄ · Na₂[Cu(mnt)₂] (1). The non-covalent supramolecular interactions among [Cu(salen)] complexes and between [Cu(salen)] and [Cu(mnt)₂]²⁻ complexes in the crystal lattice of 1 result in weak antiferromagnetic coupling.     

Luminescent Organic–Inorganic Hybrids of Functionalized Mesoporous Silica SBA-15 by Thio-Salicylidene Schiff Base

Novel organic–inorganic mesoporous luminescent hybrid material N,N′-bis(salicylidene)-thiocarbohydrazide (BSTC-SBA-15) has been obtained by co-condensation of tetraethyl orthosilicate and the organosilane in the presence of Pluronic P123 surfactant as a template. N,N′-bis(salicylidene)-thiocarbohydrazide (BSTC) grafted to the coupling agent 3-(triethoxysilyl)-propyl isocyanate (TESPIC) was used as the precursor for the preparation of mesoporous materials. In addition, for comparison, SBA-15 doped with organic ligand BSTC was also synthesized, denoted as BSTC/SBA-15. This organic–inorganic hybrid material was well-characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy (HRTEM), and photoluminescence spectra, which reveals that they all have high surface area, uniformity in the mesostructure. The resulting materials (BSTC-SBA-15 and BSTC/SBA-15) exhibit regular uniform microstructures, and no phase separation happened for the organic and the inorganic compounds was covalently linked through Si–O bonds via a self-assemble process. Furthermore, the two materials have different luminescence range: BSTC/SBA-15 presents the strong dominant green luminescence, while BSTC-functionalized material BSTC-SBA-15 shows the dominant blue emission.     

Synthesis of 4-acylpyrazolone Schiff base ligand grafted silica and selectivity in adsorption of lanthanides from aqueous solutions

The Schiff base form of the 4-acylpyrazoione ligand was immobilized on the silica surface by reaction of 3-aminopropyl silica with 4-acetyl-5-methyl-2-phenyl-2,4-dihydro-pyrazol-3-one in 97% yield, producing grafted silica with 0.77 mmol/g ligand loading. This surface modified silica was shown to be selective in the adsorption of Yb3+ ions from dilute aqueous solutions, for which 98% adsorption was observed from a 1.0×10-5 mol/L aq. solution at pH 6.7, after 24 h at room temperature. Six other lanthanides studied Eu3+, Gd3+, Nd3+, Tb3+,Sm3+ and La3+ showed moderate to weaker adsorptions of 39%, 28%, 16%, 12%, 11% and 5% respectively under similar conditions.     

镍金属催化剂对L-丙交酯的开环聚合效果分析

本文合成了三种希夫碱镍金属催化剂：NiL1 (乙二胺缩香草醛Ni(Ⅱ))、NiL2 (邻苯二胺缩3,5-二叔丁基水杨醛Ni(Ⅱ))、NiL3 (1S,2S-二苯基乙二胺缩水杨醛镍),并用IH NMR、X-ray单晶衍射等方法对新合成的催化剂NiL3进行了表征。以NiL1为催化剂通过单因素分析,选择合适的L-LA(左旋丙交酯)本体开环聚合条件,在此聚合条件下,对比不同配体结构特点的催化剂NiL1、NiL2、NiL3的催化聚合效果,结果表明：催化剂配体结构中引入供电子基团甲氧基有利于提高催化剂活性;配体结构中在金属活性中心周围增大位阻效应有利于得到分子量分布较窄的聚合产物。     

Exploiting anionic and cationic interactions with a new emissive imine-based β-naphthol molecular probe

A new emissive molecular probe derived from 1,7-bis(2′-formylphenyl)-1,4,7-trioxaheptane and 2-hydroxy-1-naphthaldehyde has been synthesized by a Schiff-base condensation method. Its sensor capability towards cations such as Cu²⁺, Zn²⁺, Cd²⁺ and Hg²⁺, and anions such as halides (F⁻, Cl⁻, Br⁻ and I⁻) and CN⁻ was explored in DMSO solution. The geometry was optimized using density functional theory (DFT). The probe showed remarkable selectivity for Cu²⁺ and interaction with the more basic anions CN⁻ and F⁻.