Search results for "OCT"
showing 10 items of 3052 documents
Soil remediation: humic acids as natural surfactants in the washings of highly contaminated soils
2005
The remediation of the highly contaminated site around the former chemical plant of ACNA (near Savona) in Northern Italy is a top priority in Italy. The aim of the present work was to contribute in finding innovative and environmental-friendly technology to remediate soils from the ACNA contaminated site. Two soils sampled from the ACNA site (A and B), differing in texture and amount and type of organic contaminants, were subjected to soil washings by comparing the removal efficiency of water, two synthetic surfactants, sodium dodecylsulphate (SDS) and Triton X-100 (TX100), and a solution of a natural surfactant, a humic acid (HA) at its critical micelle concentration (CMC). The extraction …
The Continuity of the Constitutions: The Examples of the Baltic States and Georgia
2016
In the paper I will analyze the renewal of the constitution in the Baltic States and Georgia after the collapse of the socialist system. The renewal of the old constitutions are infrequent events in the world. In the Baltic States and Georgia, the restoration of the old constitutions had symbolic and political importance, reinforcing the doctrine of state continuity and legitimizing the new constitutional order after the transformation. I also will analyze the legal force of the constitutions after the occupation of the Baltic States by the USSR. The constitutions were of particular importance for the national resistance movements, since the validity of the constitutions was grounds for exi…
Histoincompatibility reactions in the hydrocoral Millepora dichotoma
1983
The xenogeneic- and allogeneic immunological specificity of the hydrocoral Millepora dichotoma has been investigated. Xenogeneic histoicompatibility reactions have been observed between this hydrocoral and a series of species belonging to the Demospongiae and to the Anthozoa (both Hexacorallia and Octocorallia). The xenogeneic histoincompatibility reactions proceed in the following sequence: (a) Species-unspecific sensitization; (b) necrosis formation, which is very likely due to an autolytic process; (c) callus formation, due to an hyperplastic growth of stolons; and (d) formation of a contact barrier in form of a barrier layer or a restored stolonial layer. Allogeneic histoincompatibility…
A new ferromagnetically coupled μ-alkoxo–μ-acetato copper(II) trinuclear complex: [Cu3(H2tea)(Htea)(CH3COO)2](ClO4) (H3tea=triethanolamine)
2005
Abstract A μ-alkoxo–μ-acetato trinuclear copper(II) complex, [Cu3(H2tea)(Htea)(CH3COO)2](ClO4) 1, has been synthesized by reacting copper(II) perchlorate, triethanolamine and sodium acetate. The unit cell contains two centrosymmetric, crystallographically independent trinuclear Cu(II) complexes and two ClO 4 - ions. The crystallographically independent trinuclear Cu(II) complexes differ mainly in some of their geometry parameters. The coordination environment of the central copper atom is square-planar, in one trinuclear entity, and elongated octahedral in the other one (in this last case, the coordination number of the central copper atom increases through the semicoordination of an oxygen…
Macrocycle-Based Spin-Crossover Materials
2009
International audience; New iron(II) complexes of formula [Fe(L1)](BF(4))(2) (1) and [Fe(L2)](BF(4))(2) x H(2)O (2) (L1 = 1,7-bis(2'-pyridylmethyl)-1,4,7,10-tetraazacyclododecane; L2 = 1,8-bis(2'-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane) have been synthesized and characterized by infrared spectroscopy, variable-temperature single-crystal X-ray diffraction, and variable-temperature magnetic susceptibility measurements. The crystal structure determinations of 1 and 2 reveal in both cases discrete iron(II) monomeric structures in which the two functionalized tetraazamacrocycles (L1 and L2) act as hexadentate ligands; the iron(II) ions are coordinated with six nitrogen atoms: four from …
The odd association of a C3h trisamidinium cation and tosylate anion with a series of linear oxalate-bridged trinuclear heterometallic complexes
2013
A series of six isostructural heterometallic trinuclear oxalate-bridged complexes of the formula (TDbenz)(2)(TsO)(2)[M(II)(H(2)O)(2){(μ-ox)M(III)(ox)(2)}(2)]·6H(2)O·2CH(3)OH (TDbenz = 1,3,5-tris[2-(1,3-diazolinium)]benzene; TsO = 4-methylbenzenesulfonate; ox = oxalate; M(III) = Fe, M(II) = Mn (1), Fe (2), Co (3); M(III) = Cr, M(II) = Mn (4), Fe (5), Co (6)) have been synthesized from (NH(4))(3)[M(III)(ox)(3)]·3H(2)O, the chloride salts of the divalent metal ions and the tosylate salt of 1,3,5-tris[2-(1,3-diazolinium)]benzene (trisamidinium). Whereas the crystal structures of compounds 2, 3, 4 and 5 have been investigated by single-crystal X-ray diffraction, the structures of 1 and 6 have be…
Synthesis and characterization of vanadyl(IV) complexes of Schiff bases derived from anthranilic acid and salicylaldehyde (or its derivatives) or ace…
1997
Anhydrous, dimeric vanadyl(IV) complexes of Schiff bases derived from [1+1] condensation of salicylaldehyde (or its derivatives) and anthranilic acid, have been synthesized from CH3CN and were characterized by elemental analysis, FTIR, EPR, absorption, TGA, cyclic voltammetry and room temperature magnetic susceptibility measurements. These complexes were found to be oxidized by air in polar solvents like MeOH and DMF to V-V products. The E(1/2) values were found to be around 660 mV indicating that the carboxylate group favours vanadyl(IV) binding when compared to the alkoxo-bound vanadium complexes. Oxidative instability of these complexes are dependent on the substituent on the salicylalde…
Copper(II) complexes of 1,4,5,8,9,12-hexaazatriphenylene with oxalate, squarate, perchlorate as auxiliary ligands or counter ion
2002
Abstract The crystal structures of [Cu(hat)(H2O)(ox)]·H2O (I), [Cu(hat)(H2O)3(sq)]·3H2O (II) and [Cu(hat)(H2O)2](ClO4)2·4H2O (III) have been determined from X-ray single crystal diffraction data (hat=1,4,5,8,9,12-hexaazatriphenylene, ox=oxalate, sq=squarate=dianion of 3,4-dihydroxy-cyclobut-3-ene-1,2-dione). Compound I crystallises in the triclinic system, space group P 1 with a=6.6626(10), b=9.2001(14), c=12.9954(19) A , α=103.301(15), β=91.414(21), γ=105.523(13)°, Z=2; compound II in the orthorhombic system, space group P212121 with a=6.9274(2), b=8.4327(3), c=34.0577(14) A , Z=4; and compound III in the monoclinic system, space group C2/c with a=22.6652(10), b=9.2220(10), c=16.1400(10) A…
Dimensionally controlled hydrogen-bonded nanostructures: synthesis, structure, thermal and magnetic behaviour of the tris-(chelated)nickel(II) comple…
2002
Abstract Single crystals of the compound of formula [Ni(bipy)3]Cl2·5.5H2O (bipy=2,2′-bipyridine) have been prepared and structurally characterised by X-ray diffraction. The structure analysis reveals that the complex has an approximate D3 symmetry. The coordination sphere consists of six nitrogen atoms of the three-bipyridine ligands in an octahedral arrangement about the nickel. One of the chlorine ions is surrounded by twelve CH⋯Cl hydrogen bonds. Three kinds of layers are found in the crystal structure: (i) the Λ-[Ni(bipy)3]2+ cation; (ii) the water/chloride positions (O(1w)/Cl(21) to O(7w)/Cl(27)); (iii) the Δ-[Ni(bipy)3]2+ cation and a chloride ion (Cl(1)). The layers are stacked in t…
A novel series of rhenium-bipyrimidine complexes: synthesis, crystal structure and electrochemical properties
2007
Four novel rhenium complexes of formula [ReCl(4)(bpym)] (1), [ReBr(4)(bpym)] (2) PPh(4)[ReCl(4)(bpym)] (3) and NBu(4)[ReBr(4)(bpym)] (4) (bpym = 2,2'-bipyrimidine, PPh(4) = tetraphenylphosphonium cation and NBu(4) = tetrabutylammonium cation), have been synthesized and their crystal structures determined by single-crystal X-ray diffraction. The structures of 1 and 2 consist of [ReX(4)(bpym)] molecules held together by van der Waals forces. In both complexes the Re(iv) central atom is surrounded by four halide anions and two nitrogen atoms of a bpym bidentate ligand in a distorted octahedral environment. The structures of 3 and 4 consist of [ReX(4)(bpym)](-) anions and PPh(4)(+) () or NBu(4)…