Hexavalent Chromium Removal and Reduction to Cr (III) by Polystyrene Tris(2-aminoethyl)amine

A commercially available chelating polymer, polystyrene tris(2-aminoethyl)amine, was used for the removal of chromium from aqueous solution. The influence of pH, contact time, adsorbent dosage and initial Cr (VI) concentration on adsorption was studied. The optimum pH for the removal of Cr (VI) was at pH 5, while optimum contact time and adsorbent dosage were 120 minutes and 10 g/L, respectively. Total chromium and Cr (VI) concentrations were analyzed by ICP-MS and UV-Visible. Adsorption isotherms using Langmuir and Freundlich isotherm models revealed that the data fitted Langmuir isotherm model better than Freundlich with a maximum adsorption capacity of 312.27 mg/g. FTIR spectroscopy, Scanning electron microscopy (SEM) and Energy Dispersive Spectrometry (EDS) analyses were performed on the adsorbent before and after binding Cr (VI). All analyses confirmed the complexation of Cr (VI) to the adsorbent. Desorption experiments using KCl solution indicated 89.3% release of chromium, rendering this method of high potential for adsorbent regeneration.

Removal of Lead Ions from Wastewater Using Functionalized Multiwalled Carbon Nanotubes with Tris(2-Aminoethyl)Amine

Recently, many attempts have been made to use carbon nanotubes in analytical chemistry, especially in adsorption of heavy metal ions from water. In this study, multiwalled carbon nanotubes (MWCNTs) were functionalized with tris(2-aminoethyl) amine. The functionalized nanoparticles were characterized using Fourier transform infrared (FTIR), thermal gravimetric analyzer (TGA), elemental analysis, and Raman spectroscopy. The results revealed that the functionalization reaction was successfully accomplished. Lead adsorption from water was carried out using functionalized MWCNTs and measured by flame atomic absorption spectrometry (FAAS). The effects of pH, shaking time, initial metal ion concentration, and adsorbent dosage on the adsorption process were studied via batch method. The results obtained showed that removal of lead ions strongly depended on the pH. Desorption study revealed that lead ions adsorbed on the functionalized MWCNTs could be desorbed at pH 3 due to breakage of complexes formed on the sorbent surface. Maximum adsorption capacity of the sorbent under the optimal conditions was 43 mg/g. This favorable adsorption capacity suggests that functionalized carbon nanotubes can be applied for removal of lead from water solutions. The data obtained were fitted with the Langmuir and Freundlich isotherm adsorption models and Langmuir model showed better agreement with the experimental data.

Synthesis and Crystal Structure of a [Cu(HTren)Cl_2]ClO_4·H_2O Complex (Tren = Tris(2-aminoethyl)amine)

The title complex [Cu（HTren）Cl2]ClO4·H2O （Tren = tris（2-aminoethyl）amine） was synthesized by the reaction of Cu（ClO4）2·6H2O with Tren.3HCl in water and methyl alcohol. The crystal （CuC6H21Cl3N4O5） is of triclinic, space group P1, with a = 8.2689（2）, b = 8.4503（3）, c = 11.6801（4） A, α= 96.9350（10）, β= 108.2440（10）, y = 90.7550（10）°, V= 768.32（4）A^3, Z = 2, Mr= 399.16, D,.= 1.725 g/cm^3,μ= 1.962 mm^-1, F（000） = 410, T= 293（2） K, the final R = 0.0479 and wR = 0.1339 for 2659 observed reflections with I 〉 2σ（I）. X-ray single-crystal structure analysis reveals that the copper（Ⅱ） atom adopts a slightly distorted square-pyramidal geometry. The distances between Cu and N atoms （N（1）, N（2）, N（3）） range from 1.975（4） to 2.116（3）A,. The bond lengths of Cu-Cl（1） and Cu-Cl（2） are 2.309（10） and 2.591（10） A, respectively. The whole crystal presents a three-dimensional network structure by hydrogen bonds.

Crystal Structures of Fluoride and Chloride Complexes of Tris[(2-benzimidazolyl)methyl]amine

The crystal structures of fluoride and chloride complexes of tris[（2-benzimidazolyl）methyl]amine 1 were characterized by X-ray crystallography. 1 adopts （73 symmetrical geometry and cone-like conformation so as to allow its three NHs to associate with the anions through hydrogen bonds. Despite the different sizes of the anions, the two crystals are unexpectedly isostructural. The binding ability of the anions of 1 in solution was also studied by using of UV-vis spectroscopy.

Synthesis and Crystal Structure of N, N'',N''-Tris-(2-oxynaphthalidene)-tris-(2-iminoethyl) Amine

N, N??, N??-Tris-(2-oxynaphthalidene)-tris-(2-iminoethyl) amine (TOTIA) has been synthesized and characterized by X-ray crystallography, and its crystal is of monoclinic, space group P21/c with a = 6.0158(5), b = 16.3851(2), c = 31.6650(3) ?, β = 90.867(2)o, V = 3120.8(5) ?3, C39H36N4O3, Mr = 608.72, Dc = 1.296 g/cm3, Z = 4, F(000) = 1288, μ(MoKα) = 0.083 cm-1, R = 0.0641 and wR = 0.1615. The total reflections were 12598 and 5410 were independent, of which 3342 were observed with I > 2σ(I). There exist strong intramolecular hydrogen bonds between hy- droxy hydrogen atoms and azomethine nitrogen atoms, and obvious π-π stacking interaction between the phenyl rings of TOTIA.

Polyvinylbenzyl Tris-Aminodicarboxylate Microspheres for the Optical Sensing of Cu²⁺Ions

In this work, a tris(2-aminoethyl)aminodicaboxylate functionality was substituted for the chloride of polyvinyl-benzyl chloride (PVBC) which was lightly cross-linked (2%) with divinyl benzene. The resulting derivatized polymer microspheres were embedded in a hydrogel matrix of poly vinyl alcohol cross-linked with glutaraldehyde to produce a sensing membrane. The latter responded selectively to Cu2+ solutions of different concentration ranges (1 × 10-4 M to 1 × 10-6 M). The response is based on the interaction between the metal cations and the negatively charged deprotonated dicarboxylate functional group, which led to neutralization of the charges. As a result, an increase in the turbidity of the sensing membrane occurred which is attributed to a change in the refractive index of the derivatized polymer microspheres relative to that of the hydrogel. The change in the turbidity of the sensing membrane was measured as absorbance using a conventional spectrophotometer. It was found that Cu2+ ions bind to the aminodicarboxylated-polymer with a formation constant, Kf, of 1 × 105 M-1. SEM, Eds and IR analyses were performed on the aminodicarboxylated microspheres and their Cu2+ complex.

Synthesis and Crystal Structure of Cd（tla）（NO3）2[TLA=tris（6—methyl—2—p

The title complex has been synthesized and its crystal structure was determined by X-ray diffraction. Prisms of Cd (C_(21)H_(24)N_4)(NO_3)_2(1) crystallize in the triclinic space group P with cell dimensions a= 8.112(1),b=8. 837(2), c=17.236(4),α=78. 80(2),β=89. 99(2),γ=74. 35(2)°,V=1167.4(6),Mr=568. 86, Z=2, F(000)=576,μ= 9.78 cm-1 and Dc= 1. 618 g/cm￣3. 2756 unique reflections with I≥3σ(I) on refinement afforded values of R=0. 047 and R_w=0. 055.The Cd(Ⅱ) atom is surrounded by three oxygen atoms from two nitrate groups and three nitrogen atoms from TLA ligand in a distorted octahedron.

Comparative Efficacy of Polyamine-Based Scavenger Resins

Polyamine-based scavenger resins containing 2, 3 and 4 nitrogen atoms have been prepared and their comparative efficacy to scavenge appropriate electrophilic chemicals (acids, acid chlorides, isocyanates and aldehydes) from solutions has been studied. As expected, the scavenging efficiency is directly proportional to the number of nucleophic nitrogens present on the resin. The results have been compared with the performance of the popular scavenger resin, namely, tris(2-aminoethyl)amine resin, to conclude that the low-cost polyamine resins now prepared can be conveniently used as effectively as the expensive commercial product.

Synthesis,Structure and Biological Activity of Zn(II) Complex with Tris(benzimidazol-2-yl-methyl)amine Ligand

A new Zn(II) mononuclear complex with tris(benzimidazol-2-yl-methyl)amine (NTB) was synthesized with stoichiometry of [Zn(NTB)NO3]NO3·DIPY·DMF (DIPY∶4,4'-dipyridyl). The complex was characterized by elemental analysis, UV and IR spectra. The crystal structure was determined by using X-ray diffraction analysis. The crystal structure indicates that four N atoms and one O atom coordinate to zinc ion to construct a distorted trigonal-dipyramid configuration. Three nonprotonated N atoms from imidazole groups are in the equatorial plane, one alkylamino N atom and one O atom from 3NO- in the axial directions. The biological activity assay shows that this complex presents certain biological activity by means of pyrogallol autoxidation and it can be called a model compound of superoxide dismutase (SOD).

三(2-苯并咪唑亚甲基)胺合锰的结构和量化计算

合成了三 ( 2 苯并咪唑亚甲基 )胺合锰 (II) (C48H5 0 N1 4 O4Mn2 Cl4) ,采用X射线单晶衍射方法测定了晶体结构 ,并进行了量子化学计算 .晶体属于单斜晶系 ,空间群P2 1 /C ,晶胞参数 :a =1 4 2 38( 7)nm ,b =2 4 80 2 ( 3)nm ,c =1 6 977( 7)nm ,β =92 51( 4)° ,V =5 9893nm3 ,Z =4 用重原子法及傅里叶合成方法解出结构 ,最终R值为 0 0 7 Mn2 + 处于变形三角双锥配位环境中 .量子化学计算表明配体具有负电荷空穴 。

铅(Ⅱ)与三(2-(6-甲基吡啶基)甲基)胺配合物的合成及晶体结构的研究

本文合成了标题配合物［Ｐｂ（ＴＬＡ）·ＮＯ３］·ＮＯ３（ＴＬＡ＝三（２－（６－甲基吡啶基）甲基）胺，对其红外光谱及晶体结构进行了研究。结果表明，晶体属单斜晶系，Ｐ２１／ｎ空间群，晶胞参数如下：ａ＝１０．２３４（２），ｂ＝１５．３４７（３），ｃ＝１５．３９５（３），β＝９９．９３（２）°，Ｖ＝２３８２（２）３，Ｚ＝４，ＤＣ＝１．８５ｋｇ／ｍ３。晶体采用直接方法和Ｆｏｕｒｉｅｒ合成解出，经全矩陈最小二乘法对原子参数进行结构修正，最后的偏差因子Ｒ＝０．０４３，ＲＷ＝０．０５４。单晶结构表明：中心铅离子是处于四方单锥配位环境，由三（２－（６－甲基吡啶基）甲基）胺的四个氮原子和一个硝酸根的氧原子形成了五配位的几何构型。

三(2-腈基乙基)胺的合成及表征

利用丙烯腈与浓氨水的加成反应合成了三(2-腈基乙基)胺,运用红外光谱、1HNMR、元素分析、ES-MS质谱及热重分析对其结构和热性质进行了表征。结果证实所制备的化合物即为目标化合物,该化合物在300℃以下具有较好的热稳定性。

三(2-氨基乙基)胺合成方法的改进

对标题化合物的合成方法进行了改进。首先用三乙醇胺与二氯亚砜在氯仿中反应制备三(2-氯乙基)胺盐酸盐,然后与邻苯二甲酰亚胺钾在二甲基甲酰胺中反应得到标题化合物的盐酸盐,最后在甲醇中用氢氧化钾中和得到标题化合物。总收率65.4%。

新型磷—氮阻燃剂三(5,5-二甲基-1,3-二氧-2-磷杂环己烷-2-氧甲基)胺的合成及应用

叙述了三（５，５二甲基１，３二氧２磷杂环己烷２氧甲基）胺的合成方法。用元素分析、ＩＲ、１ＨＮＭＲ验证了化合物的结构，分析了除水剂、催化剂等反应条件对反应结果的影响。在聚氨酯软泡中的应用表明。

以三(2-氨基乙基)胺为核的PAMAM与Zn^(2+)的络合作用研究

以三(2-氨基乙基)胺为核,通过发散法合成了不同代数的树状聚酰胺胺(PAMAM),并利用FT-IR、1H NMR等技术对合成的产物进行表征,结果表明所合成产物的分子结构与理论结构相符。合成的PAM-AM具有大量的伯胺、叔胺和酰胺,可以作为Zn2+的络合剂。采用荧光分光光度法研究了PAMAM与Zn2+的络合作用,探讨了PAMAM的代数、Zn2+与PAMAM的摩尔比、溶液pH值、反应时间和温度对络合的影响。结果表明PAMAM的代数越高,所络合的Zn2+数目越多,且与理论值相符;随着Zn2+与PAMAM摩尔比的增加,络合形式发生变化;溶液pH值对络合体系有显著影响,强酸性条件下,PAMAM的伯胺和叔胺被质子化,H+取代Zn2+,Zn2+从络合体系中释放出来,这为PAMAM的循环利用提供了理论依据;另外,反应时间和温度对PAMAM与Zn2+的络合也有一定影响,延长反应时间和升高反应温度均使络合程度增加。

过渡金属苦味酸盐与三(2-苯并咪唑亚甲基)胺配合物的合成与表征

合成了六种过渡金属苦味酸盐与三(2 苯并咪唑亚甲基)胺配合物,并通过元素分析、红外光谱、紫外-可见光谱和摩尔电导进行了表征,其结果表明配合物的组成为[ML(Pic)]Pic(M=Mn2+、Co2+、Ni2+、Cu2+、Zn2+、Cd2+;L=三(2 苯并咪唑亚甲基)胺;Pic=苦味酸根阴离子),中心离子的配位数为5,两个苦味酸根离子只有一个和中心离子直接配位,所有的配合物在丙酮中均表现为1∶1型电解质。

三[2-(2'-肟亚甲基苯氧基)乙基]胺的合成、表征及量化研究

合成了三[2-(2'-肟亚甲基苯氧基)乙基]胺, 测定了其 IR, NMR 和单晶结构, 晶体 C27H30N4O6属三斜晶系, 空间群R-3r, 晶胞参数为: a=1.9100(2) nm, b=1.9100(2) nm, c=1.9100(2) nm, α=109.500(2)°, β=109.500(2)°. γ=109.500(2)°,Z=6. 结构解析最终一致性因子 R1=0.0568, wR2=0.1766. 分子间通过氢键和范德华力形成 3D 网状超分子结构. 使用HyperChem6.0 程序中半经验 ZINDO/1 方法和 G98 量子化学程序包, 在 B3LYP/6-311G**基组水平上对化合物电荷分布进行了量子化学计算.

三(苯并咪唑-2-亚甲基胺)锌配合物的晶体结构和量化计算

以三(苯并咪唑-2-亚甲基胺)(NTB)为配体合成了ZnNTB·(NO3)2·DIPY·DMF(DIPY:4,4'-联吡啶)的单核锌配合物,用X-射线衍射法对其晶体结构进行了测定.晶体学参数:C37H36N12O7Zn,Mr=826.16,triclinic,a=0.9856(3)nm,b=1.2655(4)nm,c=1.5965(5)nm,α=81.714(5)o,β=76.601(5)o,γ=81.504(5)o,V=1.9032(10)nm3,Dc=1.442g/cm3,Z=2,F(000)=856,μ=0.712mm-1,空间群为P-1.采用经典的邻苯三酚自氧化法,对配合物进行了活性测试,其pI50值为4.21,说明该配合物具有拟SOD活性.利用G98量子化学程序包,在B3LYP/LanLDZ基组水平上对配合物C37H36N12O7Zn进行量子化学计算,对其分子轨道能量、电荷分布和前线轨道的贡献分析可知,所合成的配合物能与超氧阴离子自由基反应,与活性测试结果相符.

三(2-苯并咪唑亚甲基 )胺合钴(Ⅱ)配合物的合成和分子结构

三 (2-苯并咪唑亚甲基 )胺 (NTB)与氯化钴(Ⅱ)在乙醇中反应生成配合物 C_(24)H_(21)N_7CoCl。在二甲亚砜溶剂中，经缓慢挥发获得其单晶 Co(NTB)Cl· 3[(CH_3)_2SO]。晶体属三斜晶系，空间群 P-1，a=0.9678(3)， b=1.1780(5),c=1.6102(9)nm,α=71.07(8),β=89.27(8),γ=84.81(3)° ,V=1.729(2)nm^3,Z=2,Dc=1.408g· cm^(－3),Mr=733.24,F(000)=762,μ =0.7864mm^(－ 1)。用 1825个 I≥ 3σ (I)的独立衍射点进行结构解析与修正，最终偏离因子 R=0.068， Rw=0.072。晶体中 Co(Ⅱ)与 NTB上的四个 N原子及一个氯离子配位，形成一个五配位的轻微扭曲的三角双锥构型。

三(2-苯并咪唑亚甲基)胺的合成及其晶体结构的测定

目的:为人工模拟合成超氧化物歧化酶(SOD)寻找与人体细胞有相似配位环境的配体。因为SOD能清除人体内的超氧阴离子自由基,而超氧阴离子自由基能加速人体衰老,引发各种炎症及自身免疫性疾病等。为此,SOD自然而然地成为科研人员的重点研究对象。方法:以市售氮三乙酸和邻苯二胺(分析纯)为原料。以有机合成的方法—加热回流制取目标化合物,在经过多次摸索后,最终以二甲亚砜为溶剂得到目标化合物的单晶体,并对其分别进行元素分析和X—射线晶体结构测定。选一大小约0.3x0.3x0.4mm^3的单晶体,以Enraf—NoniusCAD4衍射仪收集衍射数据,共收集有效衍射点1592个,以直接法解析晶体结构。结果:此晶体属单斜晶系,空间群为P21/n.晶胞参数分别为a=9.961A,b=12.308A,c=18.191A,β=91.37°),最终的偏离因子为R=0.063。结论:X—射线晶体结构分析表明,从人体红细胞中提取的Cu—Zn SOD的结构中,Cu^(2O+)分别与组氨酸的三个咪唑氮原子配位,形成四方平面构型。而本文合成的配体中,每个咪唑基团均有一个氮原子可与金属离子配位,恰好能提供与人体细胞相似的配位环境,从而为今后人工模拟合成SOD的研究奠定了理论和实验基础。