一个新颖的由Zn配合物修饰的Keggin型钴钨酸盐：[Zn(2,2’-bipy)3]3{[Zn(2,2’-bipy)2(H2O)]2 [HCoW12O40] 2 }.H2O

通过水热合成技术,一个新颖的基于Zn配合物修饰的Keggin型钴钨酸的有机-无机杂化化合物：[Zn(2,2’-bipy)3]3{[Zn(2,2’-bipy)2(H2O)]2 [HCoW12O40] 2 }.H2O已经被合成,化合物通过红外光谱、热重分析和单晶X-射线衍射进行了表征。单晶X-射线衍射的结果显示标题化合物是由一个单支撑的{[Zn(2,2’-bipy)2(H2O)]2 [HCoW12O40] 2}6-多阴离子,三个[Zn(2,2’-bipy)3]2+阳离子和一个水分子构成。有趣的是[Zn(1)(2,2’-bipy)3]2+阳离子通过氢键连接在一起形成螺旋链。另外标题化合物在空气中是稳定的,并且在室温下显示了强的荧光。     

Electrochemical synthesis of Co,Ni, and Zn complexes with 2-Pyrrole-[N-(o-hydroxyphenyl)methylimines]: The crystal structure of 2,2′-Bipyridine bis{2-[(2-pyrrole)methylimino]5-methylphenolato}nickel(II)

The electrochemical oxidation of anodic cobalt, nickel, and zinc in acetonitrile containing both 2-pyrrole-[N-(o-hydroxyphenyl)methylimines] (H₂L) and a bidentate ligand (1, 10-phenanthroline(phen) or 2,2′-bipyridine(bipy)) yielded compounds of general formula M(HL)₂ · phen and M(HL)₂ · bipy (M = Co, Ni, Zn). The crystal structure of 2,2′-bipyridine bis{2-[(2-pyrrole)methylimino]5-methylphenolato}nickel(II) was determined by X-ray diffraction. This compound crystallizes in the orthorhombic space group Pccn with a = 19.430(2), b = 28.488(2), c = 17.567(1) Å. The nickel atom has a distorted octahedral geometry, and the pyrrole nitrogen is not coordinated. The IR, ¹H-NMR and UV-visible spectra of the complexes are discussed and related to the structure.     

Gemischtligandkomplexe des Technetiums. XV. Zur Reaktion von [TcNCl2(Me2PhP)3] mit Dialkyldithiocarbamaten und N,N-Dialkylthiocarbamoylbenzamidinen

Mixed-ligand Complexes of Technetium. XV. The Reaction of [TcNCl₂(Me₂PhP)₃] with Dialkyldithiocarbamates and N,N-Dialkylthio-carbamoylbenzamidines [TcN(Cl)(Me₂PhP)₂(Et₂dtc)], [TcN(Me₂PhP)(Et₂dtc)₂], and [TcN(Et₂dtc)₂] can be prepared by stepwise ligand exchange reactions starting from dichlorotris(dimethylphenylphosphine)nitridotechnetium(V), [TcNCl₂(Me₂PhP)₃], and diethyldithiocarbamate. In contrast to this, only one intermediate, [TcN(Cl)(Me₂PhP)₂(HEt₂tcb)], could be isolated during the reaction with N,N-Diethlthiocarbamoylbenzamidine, which yields the bis chelate [TcN(HEt₂tcb)₂]. [TcN(Me₂PhP)(Et₂dtc)₂] crystallizes in the monoclinic space group P2₁/c; a = 17.369(5) Å, b = 15.024(1) Å, c = 9.906(3) Å, β = 76.47(1)º, Z = 4. The phosphine is coordinated equatorially. The multiply bonded nitrogen ligand (Tc? N(1) 1.624(3) Å) strongly labilizes the trans positioned donor atom (distance Tc? S(4) 2.826(1) Å). [TcN(HEt₂tcb)₂] crystallizes in the triclinic space group P1 with a = 9.749(4) Å, b = 11.264(4) Å, c = 12.359(4) Å, α = 75.34(2)º, β = 79.69(2)º, γ = 87.55(2)º, Z = 2. The metal is five-coordinate with the nitrido donor atom occupying the apex of a square pyramid. It's basal plane is formed by the cis-coordinated chelate ligands. The technetium is situated over the basal plane by about 0.6 Å. The Tc?N distane was found to be 1.610(5) Å.     

Electrochemical synthesis of Nickel(II) Complexes of schiff bases: The crystal structure of 2,2′-bipyridine bis{2-[(phenyl)iminomethyl]pyrrolato}nickel(II)

The electrochemical oxidation of anodic nickel in acetonitrile solution containing both (a) a Schiff base HL derived from H-pyrrole-2-carbaldehyde and a substituted aniline, and (b) a nitrogen ligand (1, 10-phenanthroline (phen), 2,2′-bipyridine (bipy) or pyridine (py)) yielded the mixed complexes NiL₂ · phen, NiL₂ · bipy and NiL₂ · (py)₂. The crystal structure of 2,2′-bipyridine bis{2-[(phenyl)iminomethyl]pyrrolato}nickel(II) was determined by X ray diffraction. Crystals are triclinic space group P1 , with four molecules in the unit cell of dimensions a = 12.316(1), b = 13.169(4), c = 17.251(3) Å, α = 82.67(3)°, β = 83.66(1)° and γ = 87.34(2)°, and consist of monomeric molecules in which the central NiN₆ unit has a distorted octahedral geometry.     

Hydrothermal Synthesis and X‐ray Crystal Structure of Four Inorganic‐Organic Hybrid Compounds in Vanadium /Copper Iodate Family

Four inorganic‐organic hybrid compounds with the formulae (1,10‐phen)(VO₂)(IO₃) ( 1 ), (2,2′‐bipy)(VO₂)(IO₃) ( 2 ), [Cu₃(2,2′‐bipy)₃Cl₃(IO₃)₂]·I_1.5 ( 3 ), and [Cu(2,2′‐bipy)(H₂O)(IO₃)₂]· (H₂O)₂ ( 4 ) are hydrothermally synthesized at 120 °C for 6 d and characterized by single‐crystal X‐ray diffraction. The use of two different bidentate organodiamine ligands 1,10‐phen and 2,2′‐bipy in the V/I/O system gives rise to compounds 1 and 2 , which crystallize in a monoclinic system with the space group C2/c, a = 17.8131(6) Å, b = 15.0470(7) Å, c = 12.9902(4) Å, β = 133.095(2)°, V = 2542.49(17) ų for 1 and space group P2₁/c, a = 13.3095(5) Å, b = 15.0993(8) Å, c = 13.0454(4) Å, β = 116.971(2)°, V = 2335.88(17) ų for 2 . The use of the bidentate organodiamine ligand 2,2′‐bipy in the Cu/I/O system gives rise to the variety in the structure of products 3 and 4 , which crystallize in a triclinic system with the same space group . a = 8.5143(2) Å, b = 10.4908(3) Å, c = 22.8420(6) Å, α = 93.769(10)°, β = 91.723(10)°, γ = 112.111(10)°, V = 1882.83(9) ų for 3 and a = 6.731(6) Å, b = 10.110(4) Å, c = 12.899(6) Å, α = 106.00(5)°, β = 95.45(4)°, γ = 107.69(6)°, V = 788.4(9) ų for 4 . The solid‐state structures of the compounds 1 and 2 have chains with repeat units of alternative corner sharing of [VO₄N₂] octahedra and [IO₃] pyramids. Compound 3 is a chain containing [IO₃] pyramids and [VO₄N] square pyramids and compound 4 consists of Cu(2,2′‐bipy)²⁺ linked by one water molecule and two [IO₃] pyramids. The thermal stabilities of the compounds are investigated.     

Gemischtligandkomplexe des Technetiums. XVI. Darstellung und Struktur von (1,2-Dicyanoethen-1,2-dithiolato)bis(dimethylphenylphosphan)nitridotechnetium (V), [TcN(Me2PhP)2(mnt)]

Mixed-Ligand Complexes of Technetiums. XVI Synthesis and Structure of (1,2-Dicyanoethene-1,2-dithiolato)bis(dimethylphenylphosphine)nitridotechnetium(V), [TcN(Me₂PhP)₂(mnt)] [TcN(Me₂PhP)₂(mnt)] is formed from [TcNCl₂(Me₂PhP)₃] and one equivalent of the sodium salt of 1,2-dicyanoethene-1,2-dithiolate (Na₂mnt). The same reaction yields [TcN(mnt)₂]^2?, when a large excess of the ligand and long reaction periods are applied. The complex anion can be isolated as tetraalkylammonium or tetraphenylarsonium salts. [TcN(Me₂PhP)₂(mnt)] crystallizes in the triclinic space group P1 (a = 10.000(5), b = 14.182(6), c = 17.77(1) Å, α = 98.77(3), β = 103.77(3), γ = 104.55(3)°; Z = 4). The coordination sphere is a square pyramid with the sulfur and phosphorus atoms as basal plane. Tc is situated out of this plane by 0.56 Å towards the nitrido ligand.     

[Au(Et2dtc)2][TcNCl4] – Darstellung und Struktur

[Au(Et₂dtc)₂][TcNCl₄] – Synthesis and Structure [Au(Et₂dtc)₂][TcNCl₄] (Et₂dtc^– = N,N‐diethyldithiocarbamate) is formed by the reaction of [Au(CO)Cl] with [TcN(Et₂dtc)₂] in dichloromethane. The solid state structure of the compound is characterized by a large triclinic unit cell (space group, P1, a = 9.422(2), b = 22.594(5), c = 32.153(7) Å, α = 72.64(1), β = 85.19(1), γ = 86.15(1)°, Z = 12) and shows an unusual arrangement due to long‐range contacts between the technetium atoms and sulfur atoms of the [Au(Et₂dtc)₂]⁺ units (3.45–3.56 Å) which assemble two anions and one cation to {[TcNCl₄][Au(Et₂dtc)₂] · [TcNCl₄]}^– moieties.     

trans‐[TcNCl2(Ph3PNH)2] — Synthesis and Structure

The neutral technetium(V) phosphoraneimine complex [TcNCl₂(Ph₂PNH)₂] is formed when (Bu₄N)[TcOCl₄] reacts with Me₃SiNPPh₃ in dichloromethane. Distances of 2.078(4) and 2.102(4) Å have been found between Tc and the neutral triphenylphosphoraneimine ligands. The Tc‐N‐P angles are 133.7(3) and 134.8(3)°. The terminal nitrido ligand is formed by decomposition of an additional molecule of Me₃SiNPPh₃. The protons which are used for the protonation of the organic ligands are released during the decomposition of CH₂Cl₂. The same reaction yields the [TcNCl₄]^— anion when it is performed in acetonitrile.     

ELECTRONIC STRUCTURES AND BONDING PROPERTIES OF MIXED LIGAND COPPER(II) COMPLEXES OF 2-(2-PYRIDYLETHYL)PICOLYLAMINE AND DIPICOLYLAMINE. MOLECULAR STRUCTURES OF (2,2′-BIPYRIDINE)[2-(2-PYRIDYLETHYL)PICOLYLAMINE]COPPER(II) PERCHLORATE AND (DIPICOLYLAMINE)(1,10-PHENANTHROLINE)COPPER(II) PERCHLORATE

Abstract

Mixed ligand copper(II) complexes of 2-(2-pyridylethyl)picolylamine (pepica) of [Cu(pepica)(pi-colinato)](ClO₄)(H₂O) and the [Cu(pepica)(L)](ClO₄)₂ type, where L stands for 2,2′-bipyridine (bipy), 1,10-phenanthroline, neocuproine, and ethylenediamine, and dipicolylamine(dipica) of the [Cu(dipica)(L)](ClO₄)₂(H₂O) _n type, where L for 2,2′-bipyridine (n = 0), 1,10-phenanthroline (phen, n = 0), and neocuproine (n = 1), have been synthesized and characterized by elemental analyses, and IR, electronic and EPR spectroscopic measurements. The molecular structures of [Cu(pepica)(bipy)](ClO₄)₂ (1) and [Cu(dipica)(phen)](ClO₄)₂ (2) have been determined using three dimensional X-ray diffraction data. Complex 1 consists of discrete distorted square pyramidal [Cu(pepica)(bipy)] cations, with a meridional pepica ligand and one of the pyridine rings of the bipy ligand forming a basal plane. The other pyridine nucleus of the bipy is bound at the apex having an elongated bond distance of 2.255 Å and tilted off the normal z axis by ～15°. Complex 2 comprises discrete distorted trigonal bipyramidal [Cu(dipica)(phen)] cations, with the two pyridine nuclei of the dipica ligand and one of the pyridine rings of the phen forming an equatorial trigonal plane and the remaining pyridine ring of the phen and the amine nitrogen of the dipica on the axial sites. The trigonal bipyramidal cation, distorted toward a square pyramidal structure, has an enlarged equatorial N(py)–Cu–N(py) angle of 132.4° and an elongated equatorial Cu–N(phen) bond of 2.156 Å. All of the complexes exhibit axial type EPR spectra. Gaussian resolved d-d spectra for these complexes, except the dipica-bipy and dipicaphen ones, yield an orbital sequence of d_x ²- _y ² ≥ d_z ² > d_xy > d_yz ～d_xz . The bonding properties of the tridentate and the bidentate ligands are elucidated.     

cis‐Bis(2,2′‐bipyridyl‐N,N′)dichlorosilicon diiodide

The crystal and molecular structure of the title compound, C₂₀H₁₆Cl₂N₄Si²⁺·2I^?, has been determined at 173 K. To our knowledge, this is the first crystal structure of a silicon tetrahalide complex with a bidentate base as a ligand. The two chloro ligands are cis relative to each other. The Si—N bonds trans to a chloro ligand are longer than the Si—N bonds trans to an Si—N bond. This feature is observed for the majority of M(bipy)₂Cl₂ (M = metal and bipy = 2,2′‐bipyridyl) complexes, but it does not hold for all structures retrieved from the Cambridge Structural Database. The two pyridyl rings of each bipyridyl unit are nearly coplanar, whereas the bipyridyl units are almost perpendicular to each other. The two I^? ions are more than 5 Å from the silicon centre. As a result, the compound can definitely be described as ionic. The crystal packing is stabilized by short C—H?I contacts.     

Weak Antiferromagnetism in Carboxylato Copper(II) Complexes of Bipyridines

Three new members of the copper/carboxylato/heterocyclic diimine family, namely [Cu(GLYO)(2, 2′‐bipy)]₂ · nH₂O (n = 4 ( 1 ) or 6 ( 2 ), H₂GLYO = glycolic acid, 2, 2′‐bipy = 2, 2′‐bipyridine) and {[Cu(AcO)₂(4, 4′‐bipy)] · 3H₂O}_n ( 3 ) (AcO = acetato, 4, 4′‐bipy = 4, 4‐bipyridine), have been synthesized and characterized by IR and electronic absorption spectroscopy, and the crystal structures have been determined by single crystal X‐ray analysis. 1 and 2 are composed of discrete dinuclear units in which each Cu^II atom is coordinated in a square pyramidal arrangement to the two nitrogen atoms of a bipyridine ligand, to bridging non‐carboxy oxygen atoms belonging to two glycolato ligands, and to one of the carboxy oxygen atoms of one of these glycolato ligands. The Cu··Cu distance is 3.0666(5)Å. Compound 3 consists of linear chains of dinuclear units in which each Cu^II is coordinated to one non‐bridging monodentate acetato ligand, to two acetato ligands that each bridge via a single oxygen atom, and to one nitrogen atom of each of two mutually trans bis‐monodentate 4, 4′‐bipyridine ligands that link the repeat units of the polymer. The coordination polyhedra are square pyramids, and the Cu··Cu distance within each dimeric repeat unit is 3.502(2)Å. The temperature dependence of their magnetic susceptibilities shows there to be weak antiferromagnetic interaction between the metal atoms of each dimer in all three complexes, with fitting parameter values of —2J = 1.3 cm^—1 and g = 2.09 for 1 and 2 , and —2J = 1.4 cm^—1 and g = 2.15 for 3 . The X‐band EPR spectra show signals corresponding to the dinuclear units.     

Hydrothermal Syntheses,Crystal Structures,and Luminescent Properties of Three Organic‐Lanthanide Complexes with 3‐Hydroxycinnamic Acid

Three new homodinuclear lanthanide(III) complexes [Ln₂(L)₆(2,2′‐bipy)₂] [Ln = Tb^III ( 1 ), Sm^III ( 2 ), Eu^III ( 3 ); HL = 3‐hydroxycinnamic acid (3‐HCA); 2,2′‐bipy = 2,2′‐bipyridine] were synthesized and characterized by IR spectroscopy, elemental analyses, and X‐ray diffraction techniques. Complexes 1 – 3 crystallize in triclinic system, space group P$\bar{1}$ . In all complexes the lanthanide ions are nine‐coordinate by two nitrogen atoms from the 2,2′‐bipy ligand and seven oxygen atoms from one chelating L ligands and four bridging L ligands, forming distorted tricapped trigonal prismatic arrangements. The lanthanide(III) ions are intramolecularly bridged by eight carboxylate oxygen atoms forming dimeric complexes with Ln ··· Ln distances of 3.92747(15), 3.9664(6), and 3.9415(4) Å for complexes 1 – 3 , respectively. The luminescent properties in the solid state of HL ligand and Eu^III complex are also discussed.     

Einfluss von H‐Brückenbindungen auf die Jahn–Teller‐Verzerrung in den Kettenstrukturen von 2,2′‐bipyMn(H2PO4)F2·H2O und 2,2′‐bipyMn(H2PO4)2F

In the system 2,2′‐bipyridine/Mn^III/HF/H₃PO₄/H₂O two compounds with chain structures could be prepared and characterised by X‐ray structure analyses. 2,2′‐bipyMn(H₂PO₄)F₂·H₂O ( 1 ): monoclinic, twinned, space group P2₁/c, Z = 4, a = 6.7883(4), b = 10.9147(5), c = 17.8102(8) Å, β = 100.142(4)°, R = 0.0328. 2,2′‐bipyMn(H₂PO₄)₂F ( 2 ): triclinic, space group P , Z = 2, a = 6.675(1), b = 10.715(1), c = 11.013(1) Å, α = 107.595(9)°, β = 90.994(9)°, γ = 95.784(8)°, R = 0.0252. Both compounds show chain structures with trans‐bridging dihydrogenphosphate ligands and bipy and two fluorine ligands for ( 1 ), or bipy, fluorine and an additional dihydrogenphosphate, respectively, for ( 2 ) in equatorial positions. Due to the pseudo‐Jahn–Teller effect, Mn^III shows elongated octahedral coordination with ferrodistortive ordering along the chain direction. The distortion is remarkably higher in ( 1 ) than in ( 2 ). This is discussed in context with additional hydrogen bonds along the chain in ( 2 ).     

Synthesis and Crystal Structure of Manganese(II) Bipyridine Carboxylato Complexes: [(bipy)2MnII(μ‐C2H5CO2)2MnII(bipy)2](ClO4)2 and [MnII(ClCH2CO2)(H2O)(bipy)2]ClO4 · H2O (bipy = 2,2′‐bipyridine)

Two manganese(II) bipyridine carboxylate complexes, [(bipy)₂Mn^II(μ‐C₂H₅CO₂)₂Mn^II(bipy)₂}₂](ClO₄)₂ ( 1 ), and [Mn^II(ClCH₂CO₂)(H₂O)(bipy)₂]ClO₄ · H₂O ( 2 ) were prepared. 1 crystallizes in the triclinic space group P 1 with a = 8.604(3), b = 12.062(3), c = 13.471(3) Å, α = 112.47(2), β = 93.86(2), γ = 92.87(3)°, V = 1211.1(6) ų and Z = 1. In the dimeric, cationic complex with a crystallographic center of symmetry two 2,2′‐bipyridine molecules chelate each manganese atom. These two metal fragments are then bridged by two propionato groups in a syn‐anti conformation. The Mn…Mn distance is 4.653 Å. 2 crystallizes in the monoclinic space group P2₁/c with a = 9.042(1), b = 13.891(1), c = 21.022(3) Å, β = 102.00(1)°, V = 2569.3(5) ų and Z = 4. 2  is a monomeric cationic complex in which two bipyridine ligands chelate the manganese atom in a cis fashion. A chloroacetato and an aqua ligand complete the six‐coordination. Only in 2 is the intermolecular packing controlled by weak π‐stacking besides C–H…π contacts between the bipyridine ligands.     

Polymorphism of [Zn(2,2′‐bipy)(H2PO4)2]2

Two polymorphs of a zero‐dimensional (molecular) zinc phosphate with the formula [Zn(2,2′‐bipy)(H₂PO₄)₂]₂ have been synthesized by a mild hydrothermal route and their crystal structures were determined by single crystal X‐ray diffraction (triclinic, space group (No. 2), Z = 2, α‐form: a = 8.664(1), b = 8.849(2), c = 10.113(2) Å, α = 97.37(2)°, β = 100.54(2)°, γ = 100.98(2)°, V = 737.5(3) ų; β‐form: a = 7.5446(15), b = 10.450(2), c = 10.750(2) Å, α = 67.32(3)°, β = 81.67(3)°, γ = 69.29(3)°, V = 731.4(3) ų). Both structures consist of distorted trigonal‐bipyramidal ZnO₃N₂ units condensed with PO₂(OH)₂ tetrahedra through common vertices giving rise to dimers [Zn(2,2′‐bipy)(H₂PO₄)₂]₂. The structures are stabilized by extensive inter‐ and intramolecular hydrogen bond interactions. Both modifications display subtle differences in their packing originating from the hydrogen bond interactions as well as π…π interactions between the organic ligands.     

Two mononuclear Tc complexes: [2,2′‐(3‐phenylpropylimino)‐ and [2,2′‐(propylimino)bis(ethanethiolato)](4‐methoxybenzenethiolato)oxidotechnate(V)

The molecular structures of the two mononuclear title complexes, namely (4‐methoxybenzenethiolato‐κS)oxido[2,2′‐(3‐phenylpropylimino)bis(ethanethiolato)‐κ³S,N,S′]technetium(V), [Tc(C₁₄H₂₁NS₂)(C₇H₇OS)O], (I), and (4‐methoxybenzenethiolato‐κS)oxido[2,2′‐(propylimino)bis(ethanethiolato)‐κ³S,N,S′]technetium(V), [Tc(C₇H₁₅NS₂)(C₇H₇OS)O], (II), exhibit the same coordination environment for the central Tc atoms. The atoms are five‐coordinated (TcNOS₃) with a square‐pyramidal geometry comprising a tridentate 2,2′‐(3‐phenylpropylimino)bis(ethanethiolate) or 2,2′‐(propylimino)bis(ethanethiolate) ligand, a 4‐methoxybenzenethiolate ligand and an additional oxide O atom. Intermolecular C—H...O and C—H...S hydrogen bonds between the monomeric units result in two‐dimensional layers with a parallel arrangement.     

Synthesis of a Ruthenium(II) Compound based on 5‐(2‐Pyrimidyl)‐1H‐tetrazole for Photodynamic Therapy

Ru^II compounds have been universally investigated due to their unique physical and chemical properties. In this paper, a new Ru^II compound based on 2,2′‐bipy and Hpmtz [2,2′‐bipy = 2,2′‐bipyridine, Hpmtz = 5‐(2‐pyrimidyl)‐1H‐tetrazole], namely [Ru(2,2′‐bipy)₂(pmtz)][PF₆] · 0.5H₂O was prepared and characterized by elemental analysis, IR and single‐crystal X‐ray diffraction. [Ru(2,2′‐bipy)₂(pmtz)][PF₆] · 0.5H₂O shows a mononuclear structure and forms a three‐dimensional network by non‐classic hydrogen bonds. The ability of generation of ROS (reactive oxygen species) makes it has a low phototoxicity IC₅₀ (half‐maximal inhibitory concentration) after Xenon lamp irradiation on Hela cells in vitro. The results demonstrate that [Ru(2,2′‐bipy)₂(pmtz)][PF₆] · 0.5H₂O with high light toxicity and low dark toxicity may be a potential candidate for photodynamic therapy.     

The influence of the ligands on the catalytic activity of a series of RhI complexes in reactions with phenylacetylene: Synthesis of stereoregular poly(phenyl) acetylene

The catalytic activity of a series of [Rh L-L chel]X complexes, in which we have varied the unsaturated ligand [L-L = cis, cis-cycloocta 1,5-diene(cod) or 2,5-norbornadiene(nbd) the nitrogen chelating ligand [chel = 2,2′-bipyridine(bipy), 2,2′-dipyridylamine(dipyam), 2,2′-bipyrazine (bipz), 4,4′-dimethyl-2,2′-bipyridine (4,4′-Me₂bipy)] and the counter ion [X = PF₆, ClO₄, BPh₄], has been examined in reactions with phyenylacetylene (PA). The catalytic behaviour of the [Rh(cod)Cl₂],tmeda (tmeda = N,N,N′,N′tetramethylethylendiamine), [Rh(cod)Cl₂],teda] (teda = triethylendiamine), of the dimer [Rh(cod)Cl]₂, and the use of NaOH as cocatalyst in different reaction conditions was also examined. The influence of the ligands on the catalytic activity of these Rh^I complexes is discussed. ¹H and ¹³C NMR spectra have shown that highly stereoregular polyphenylacetilene can be obtained. Conditions for homogeneous doping of PPA, to obtain materials whose conductivity varies over 10–11 magnitude orders, are proposed. The stability of the doped polymers is also discussed.     

SOCl2 and POCl3 as reducing agents for TcO 4 − formation and EPR detection of Tc(VI)-compounds

Pertechnetate, TcO ₄ ^– , is reduced by thionyl chloride and phosphoryl chloride, respectively, to yield semistable Tc(VI) intermediates which can easily be detected by EPR spectroscopy. Spectra are recorded in liquid and frozen solutions. EPR data as well as chemical behaviour suggest the compounds obtained to be oxochloro complexes of technetium(VI).     

Structural Relationships Afforded by the Coordination of 2,2′-Bipyridine to the (Iminodiacetato)Copper(II) Chelate: Synthesis,Structure and Properties of (2,2′-Bipyridine) (N-(2-Hydroxyethyl)Iminodiacetato) Copper(II)Tetrahydrate

Abstract

The stoichiometric reaction of copper(II) hydroxycarbonate, N-(2-hydroxyethyl)iminodiacetic acid [H₂heida?HOCH₂CH₂N(CH₂CO₂H)₂)] and 2,2′-bipyridine (bipy) in water yields crystalline (2,2′-bipyridine)(N-(2-hydroxyethyl)iminodiacetato)copper(II) tetrahydrate, [Cu(heida)-(bipy)] · 4H₂O (compound I). This was studied by TG analysis (with FT-IR study of evolved gases), IR, electronic and ESR spectra, magnetic susceptibility data and single crystal X-ray diffraction methods. The compound crystallises in the triclinic system, space group P1, a = 7.011(2), b = 12.586(3), c = 13.052(3) Å, α = 62.14(1), β = 80.51(2), γ = 77.09(2)°, Z = 2, final R ₁ = 0.051 for 3900 independent reflections. The Cu(II) atom exhibits an asymmetric, elongated, octahedral coordination (type 4+1 + 1), and bipy acts as an N,N-bidentate ligand supplying two among the four closest donor atoms of the metal (Cu-N bond lengths of 1.994(2) and 2.053(2) Å); heida plays an N,O,O′,O″-tetradentate chelating role (bond lengths Cu?N = 2.075(2), Cu-O(carboxyl) = 1.958(2), Cu-O′(carboxyl) = 2.337(2) and Cu-O″(hydroxyl) = 2.459(2) Å). The effective bidentate chelation of bipy imposes fac-chelation to the iminodiace-tate moiety of heida in I, as previously reported in mixed-ligand complexes having a 1:1:2 Cu(II)/IDA/N(heterocyclic) or a 1/1/(1 + 1) Cu/IDA/(N-heterocyclic + N-aliphatic) donor ratio. The tetradentate role of heida in I reveals its noticeable conformational flexibility. The crystal features a hydrogen bond network forming supra-molecular chains extending along the a axis. These are linked by two symmetry-related hydrogen bonds of the type O(hydroxyl)-H…O′(carboxyl) between two adjacent complex units (symmetry code i=-x, -y+1, -z+1), related to each other by an inversion centre.