The reaction between Ce (IV ) and NTA was investigated titrimetrically and spectrophotometrically. Two equivalents of Ce( IV ) are reduced per mole of NTA almost instantaneously at room temperature. With increasing re...The reaction between Ce (IV ) and NTA was investigated titrimetrically and spectrophotometrically. Two equivalents of Ce( IV ) are reduced per mole of NTA almost instantaneously at room temperature. With increasing reaction time an ultimate of about 7 equivalents of Ce( IV) is consumed per mole of NTA at room temperature. Carbon dioxide, formaldehyde and dimethylamine are the major and readily detectable products of oxidation of NTA by Ce( IV ). The rates of the reaction in HClO4 were measured spectrophotometricaUy using the stopped flow technique. The effects of both acidity of the medium and added salts support and extend preliminary results.展开更多
Yb 3+ complexes with two nitrilotriacetic acid molecules were prepared and their compositions were determined as K 3[Yb(nta) 2(H 2O)]·5H 2O and Na 3[Yb(nta) 2]·6H 2O by elemental analyses. Their structures w...Yb 3+ complexes with two nitrilotriacetic acid molecules were prepared and their compositions were determined as K 3[Yb(nta) 2(H 2O)]·5H 2O and Na 3[Yb(nta) 2]·6H 2O by elemental analyses. Their structures were characterized by single crystal X ray diffraction analyses. In complex K 3[Yb(nta) 2(H 2O)]·5H 2O, the YbN 2O 7 part forms a nine coordinate monocapped square antiprismatic structure. In complex Na 3[Yb(nta) 2]·6H 2O, the YbN 2O 6 part forms an eight coordinate square antiprismatic structure. It can be seen that the outer cations (K + and Na +) greatly affect the coordination number and coordinate structure from these results.展开更多
By using spectrophotometric and potentiometric techniques the formation constants of the species formed in the systems H^＋＋ Mo（Ⅵ）＋nitrilotriacetic acid and H^＋ ＋ nitrilotriacetic acid have been determined in ...By using spectrophotometric and potentiometric techniques the formation constants of the species formed in the systems H^＋＋ Mo（Ⅵ）＋nitrilotriacetic acid and H^＋ ＋ nitrilotriacetic acid have been determined in aqueous solutions of propanol at 25 ℃ and constant ionic strength 0.1 molodm^-3 sodium perchlorate. The composition of the complex was determined by the continuous variation method. It was shown that molybdenum（Ⅵ） forms a mononuclear 1 ： 1 complex with nitrilotriacetic acid of the type MoO3L^-3 at -lg[H^＋] =5.8. The formation constants in various media were analyzed in terms of Kamlet and Taft＇s parameters. Linear relationships were observed when lg Ks was plotted versusp. Finally, the results were discussed in terms of the effect of solvent on complexation.展开更多
The heteronuclear gadolinium copper complex was synthesized. Its crystal structure was determined by single crystal diffraction. The crystal crystallizes in triclinic, space group P 1, a=0 8483(1) nm, b =0 ...The heteronuclear gadolinium copper complex was synthesized. Its crystal structure was determined by single crystal diffraction. The crystal crystallizes in triclinic, space group P 1, a=0 8483(1) nm, b =0 9642(2) nm, c =1 2838(2) nm, α =111 17(1)°, β = 93 52(1)°, γ =100 89(1)°, Z =2, D c=2 335 g·cm -3 . The complex appears as a zigzag 1D chain. Each gadolinium ion is coordinated by three carboxylic oxygen atoms and six oxygen atoms from H 2O. Each copper ion is chelated by NTA with its nitrogen atom and three oxygen atoms of three carboxyl groups, and coordinated by a chlorine ion. The ClO 4 - is located between the chains as a counter ion.展开更多
The crystal and molecular structures of K3[TbIII(nta)2(H2O)]5.5H2O (nta = nitrilotriacetic acid) and K3[YbIII(nta)2]5H2O complexes have been determined by single-crystal X- ray structural analyses. Because TbIII and Y...The crystal and molecular structures of K3[TbIII(nta)2(H2O)]5.5H2O (nta = nitrilotriacetic acid) and K3[YbIII(nta)2]5H2O complexes have been determined by single-crystal X- ray structural analyses. Because TbIII and YbIII have different ionic radii and electronic configura- tions, they take nine- and eight-coordinate structures with two nta ligands, respectively. The crystal of K3[TbIII(nta)2(H2O)]5.5H2O belongs to orthorhombic, space group Pccn with a = 1.6374(7), b = 1.9913(8), c = 1.5068(6) nm, V = 4.913(3) nm3, Z = 8, Mr = 769.54, Dc = 2.081 g/cm3, m = 3.476 mm-1 and F(000) = 3048. The final R and wR are 0.0432 and 0.0916 for 4961 observed reflections (I > 2.0s(I)), and 0.0814 and 0.1042 for all 21921 reflections, respectively. The [TbIII(nta)2(H2O)]3- complex anion has a nine-coordinate pseudo-monocapped square anti-prismatic structure, in which two N and six O coordinated atoms are from two nta ligands and the left ninth O atom from one water molecule. The crystal of K3[YbIII(nta)2]5H2O is of monoclinic, space group P21/c with a = 1.5579(5), b = 0.9981(3), c = 1.5956(5) nm, b = 109.776(5), V = 2.3348(13) nm3, Z = 4, Mr = 756.62, Dc = 2.153 g/cm3, m = 4.624 mm-1 and F(000) = 1484. The final R and wR are 0.0253 and 0.0657 for 4123 observed reflections (I > 2.0s(I)), and 0.0320 and 0.0731 for all 9414 reflections, respectively. The [YbIII(nta)2]3- complex anion has an eight-coordination structure with a distorted square antiprismatic prism, in which each nta acts as a tetradentate ligand with one N atom from the amino group and three O atoms from the carboxylic groups.展开更多
A novel La(Ⅲ)-Cu(Ⅱ)heterometallic coordination polymer {[LaCu2(NTA)2(4,4'-bpy)(H2O)3]NO3 5H2O}n,where H3NTA denotes nitrilotriacetic acid and 4,4'-bpy denotes 4,4'-bipyridine,was synthesized and characte...A novel La(Ⅲ)-Cu(Ⅱ)heterometallic coordination polymer {[LaCu2(NTA)2(4,4'-bpy)(H2O)3]NO3 5H2O}n,where H3NTA denotes nitrilotriacetic acid and 4,4'-bpy denotes 4,4'-bipyridine,was synthesized and characterized by IR spectrum,elemental analysis and X-ray diffraction.The complex crystallizes in the triclnic space group PT with cell parameters a=1.33710(10)nm,b=1.44530(10)nm,c=1.0949(2)nm,α=71.905(7),β=74.327(7),γ=64.427(9),V=1.7912(4)nm3 and Z=2.It consists of heterometallic units,in which each La(Ⅲ)ion is coordinated in a distorted mono-capped square antiprism by three oxygen atoms from water molecules and six carboxyl oxygen atoms from five NTA3-ions,and each Cu(Ⅱ)ion is coordinated by one nitrogen atom from 4,4'-bpy and one nitrogen atom,three oxygen atoms from NTA3-.In the title complex,La(Ⅲ)ions and Cu(Ⅱ)ions are connected by the heterometallic bridging of NTA3-,constructing a two-dimensional network structure along the [110].And it is extended into an infinite three-dimensional network structure by the formation of homometallic bridging of Cu-4,4'-bpy-Cu,exhibiting a certain inclusion ability.展开更多
文摘The reaction between Ce (IV ) and NTA was investigated titrimetrically and spectrophotometrically. Two equivalents of Ce( IV ) are reduced per mole of NTA almost instantaneously at room temperature. With increasing reaction time an ultimate of about 7 equivalents of Ce( IV) is consumed per mole of NTA at room temperature. Carbon dioxide, formaldehyde and dimethylamine are the major and readily detectable products of oxidation of NTA by Ce( IV ). The rates of the reaction in HClO4 were measured spectrophotometricaUy using the stopped flow technique. The effects of both acidity of the medium and added salts support and extend preliminary results.
基金Supported by the Natural Science Fund of L iaoning Province and Shenyang City Science and Technology Comm ittee
文摘Yb 3+ complexes with two nitrilotriacetic acid molecules were prepared and their compositions were determined as K 3[Yb(nta) 2(H 2O)]·5H 2O and Na 3[Yb(nta) 2]·6H 2O by elemental analyses. Their structures were characterized by single crystal X ray diffraction analyses. In complex K 3[Yb(nta) 2(H 2O)]·5H 2O, the YbN 2O 7 part forms a nine coordinate monocapped square antiprismatic structure. In complex Na 3[Yb(nta) 2]·6H 2O, the YbN 2O 6 part forms an eight coordinate square antiprismatic structure. It can be seen that the outer cations (K + and Na +) greatly affect the coordination number and coordinate structure from these results.
文摘By using spectrophotometric and potentiometric techniques the formation constants of the species formed in the systems H^＋＋ Mo（Ⅵ）＋nitrilotriacetic acid and H^＋ ＋ nitrilotriacetic acid have been determined in aqueous solutions of propanol at 25 ℃ and constant ionic strength 0.1 molodm^-3 sodium perchlorate. The composition of the complex was determined by the continuous variation method. It was shown that molybdenum（Ⅵ） forms a mononuclear 1 ： 1 complex with nitrilotriacetic acid of the type MoO3L^-3 at -lg[H^＋] =5.8. The formation constants in various media were analyzed in terms of Kamlet and Taft＇s parameters. Linear relationships were observed when lg Ks was plotted versusp. Finally, the results were discussed in terms of the effect of solvent on complexation.
文摘The heteronuclear gadolinium copper complex was synthesized. Its crystal structure was determined by single crystal diffraction. The crystal crystallizes in triclinic, space group P 1, a=0 8483(1) nm, b =0 9642(2) nm, c =1 2838(2) nm, α =111 17(1)°, β = 93 52(1)°, γ =100 89(1)°, Z =2, D c=2 335 g·cm -3 . The complex appears as a zigzag 1D chain. Each gadolinium ion is coordinated by three carboxylic oxygen atoms and six oxygen atoms from H 2O. Each copper ion is chelated by NTA with its nitrogen atom and three oxygen atoms of three carboxyl groups, and coordinated by a chlorine ion. The ClO 4 - is located between the chains as a counter ion.
基金This work was financially supported by the National Natural Science Foundation of China (No. 20371023)
文摘The crystal and molecular structures of K3[TbIII(nta)2(H2O)]5.5H2O (nta = nitrilotriacetic acid) and K3[YbIII(nta)2]5H2O complexes have been determined by single-crystal X- ray structural analyses. Because TbIII and YbIII have different ionic radii and electronic configura- tions, they take nine- and eight-coordinate structures with two nta ligands, respectively. The crystal of K3[TbIII(nta)2(H2O)]5.5H2O belongs to orthorhombic, space group Pccn with a = 1.6374(7), b = 1.9913(8), c = 1.5068(6) nm, V = 4.913(3) nm3, Z = 8, Mr = 769.54, Dc = 2.081 g/cm3, m = 3.476 mm-1 and F(000) = 3048. The final R and wR are 0.0432 and 0.0916 for 4961 observed reflections (I > 2.0s(I)), and 0.0814 and 0.1042 for all 21921 reflections, respectively. The [TbIII(nta)2(H2O)]3- complex anion has a nine-coordinate pseudo-monocapped square anti-prismatic structure, in which two N and six O coordinated atoms are from two nta ligands and the left ninth O atom from one water molecule. The crystal of K3[YbIII(nta)2]5H2O is of monoclinic, space group P21/c with a = 1.5579(5), b = 0.9981(3), c = 1.5956(5) nm, b = 109.776(5), V = 2.3348(13) nm3, Z = 4, Mr = 756.62, Dc = 2.153 g/cm3, m = 4.624 mm-1 and F(000) = 1484. The final R and wR are 0.0253 and 0.0657 for 4123 observed reflections (I > 2.0s(I)), and 0.0320 and 0.0731 for all 9414 reflections, respectively. The [YbIII(nta)2]3- complex anion has an eight-coordination structure with a distorted square antiprismatic prism, in which each nta acts as a tetradentate ligand with one N atom from the amino group and three O atoms from the carboxylic groups.
基金Project supported by the National Natural Science Foundation of China (No. 29761002)the Ten, Hundred or Thousand Distinguished Person Foundation of Guangxi, China
文摘A novel La(Ⅲ)-Cu(Ⅱ)heterometallic coordination polymer {[LaCu2(NTA)2(4,4'-bpy)(H2O)3]NO3 5H2O}n,where H3NTA denotes nitrilotriacetic acid and 4,4'-bpy denotes 4,4'-bipyridine,was synthesized and characterized by IR spectrum,elemental analysis and X-ray diffraction.The complex crystallizes in the triclnic space group PT with cell parameters a=1.33710(10)nm,b=1.44530(10)nm,c=1.0949(2)nm,α=71.905(7),β=74.327(7),γ=64.427(9),V=1.7912(4)nm3 and Z=2.It consists of heterometallic units,in which each La(Ⅲ)ion is coordinated in a distorted mono-capped square antiprism by three oxygen atoms from water molecules and six carboxyl oxygen atoms from five NTA3-ions,and each Cu(Ⅱ)ion is coordinated by one nitrogen atom from 4,4'-bpy and one nitrogen atom,three oxygen atoms from NTA3-.In the title complex,La(Ⅲ)ions and Cu(Ⅱ)ions are connected by the heterometallic bridging of NTA3-,constructing a two-dimensional network structure along the [110].And it is extended into an infinite three-dimensional network structure by the formation of homometallic bridging of Cu-4,4'-bpy-Cu,exhibiting a certain inclusion ability.
