Search results for "Oct"
showing 10 items of 3052 documents
Synthesis and crystal structure of the low-spin iron(II) complex [Fe(bpz)3](ClO4)2·H2O (bpz=2,2′-bipyrazine)
2004
Abstract The crystal structure of the title compound [Fe(bpz) 3 ](ClO 4 ) 2 · H 2 O (bpz=2,2 ′ -bipyrazine) has been determined by a single crystal X-ray diffraction study at 293(2) K. The complex is monoclinic, P 2 1 / c , a =17.263(3), b =9.983(2), c =17.921(4) A, β =107.94(3)°, V =2938.3(10) A 3 , Z =4, R =0.073 and R w =0.118. The structure is made up of tris-chelated [Fe(bpz) 3 ] 2+ cations, uncoordinated perchlorate anions and crystallization water molecules. The iron atom exhibits a FeN 6 distorted octahedral geometry with average Fe–N bond length and N–Fe–N bidentate angle of 1.962(5) A and 81.6(2)°. The value of the Fe–N bond distance and that of the room temperature magnetic mome…
Synthesis crystal structure and magnetic properties of [Fe2(bpym)(C5O5)2(H2O)4]·2H2O and two polymorphs of [Fe2(bpym)(C4O4)2(H2O)6]·2H2O (bpym = 2,2′…
1998
Abstract Two dinuclear iron(II) complexes of formulae [Fe2(bpym)(C5O5)2(H2O)4]·2H2O (1) and [Fe2(bpym)(C4O4)2(H2O)6]·2H2O (2) (bpym = 2,2-bipyrimidine, C5O52 = dianion of croconic acid (4,5-dihydroxycylopent-4-ene-1,2,3-trione) and C4O42 = dianion of squaric acid (3,4-dihydroxycyclobut-3-ene-1,2-dione)) were prepared and their crystal structures (at 103 K) determined by X-ray diffraction methods. The structure of 1 consists of neutral centrosymmetric [Fe2(bpym)(C5O5)2(H2O)4] units and water molecules of crystallization which are linked by an extensive network of hydrogen bonds. The coordination geometry around each iron atom is that of a compressed octahedron with bpym nitrogen atoms and cr…
Coordinating behaviour of 3-methyl[1,2,3]triazolo[1,5-a]pyridine (tzpy): crystal and molecular structure and electronic properties of [Cu(tzpy)2(ONO2…
1999
Abstract The crystal and molecular structure of [Cu(tzpy) 2 (ONO 2 ) 2 (OH 2 )] (tzpy=3-methyl[1,2,3]triazolo[1,5- a ]pyridine) has been determined by X-ray diffraction methods. The crystal structure is built up of discrete [Cu(tzpy) 2 (ONO 2 ) 2 (OH 2 )] entities linked through hydrogen bonds. The coordination geometry around the copper atom can be described as an elongated and strongly distorted octahedron displaying a 4+1+1* coordination mode (CuN 2 O 2 O′O″ chromophore), with one of the nitrato groups acting as bidentate and involved in a weak off-the- z -axis coordination. Spectroscopic properties are interpreted on the basis of the above stereochemistry.
New cyanide-bridged Mn(III)-M(III) heterometallic dinuclear complexes constructed from [M(III)(AA)(CN)4]- building blocks (M = Cr and Fe): synthesis,…
2011
Three Mn(III)-M(III) (M = Cr and Fe) dinuclear complexes have been obtained by assembling [Mn(III)(SB)(H(2)O)](+) and [M(III)(AA)(CN)(4)](-) ions, where SB is the dianion of the Schiff-base resulting from the condensation of 3-methoxysalicylaldehyde with ethylenediamine (3-MeOsalen(2-)) or 1,2-cyclohexanediamine (3-MeOsalcyen(2-)): [Mn(3-MeOsalen)(H(2)O)(µ-NC)Cr(bipy)(CN)(3)]·2H(2)O (1), [Mn(3-MeOsalen)(H(2)O)(µ-NC)Cr(ampy)(CN)(3)][Mn(3-MeOsalen)(H(2)O)(2)]ClO(4)·2H(2)O (2) and [Mn(3-MeOsalcyen)(H(2)O)(µ-NC)Fe(bpym)(CN)(3)]·3H(2)O (3) (bipy = 2,2'-bipyridine, ampy = 2-aminomethylpyridine and bpym = 2,2'-bipyrimidine). The [M(AA)(CN)(4)](-) unit in 1-3 acts as a monodentate ligand towards th…
Synthesis, crystal structure and magnetic properties of novel heterobimetallic malonate-bridged MIIReIV complexes (M = Mn, Fe, Co and Ni).
2008
Five novel ReIV-MII bimetallic complexes of formula [ReCl4(mu-mal)M(dmphen)2].MeCN [M = Co (1), Fe (2) and Ni (3)], [ReCl4(mu-mal)Ni(dmphen)(MeCN)2(H2O)].(MeCN)0.5(H2O)0.5 (4), and [ReCl4(mu-mal)Mn(dmphen)(H2O)2].dmphen.MeCN.H2O (5) (mal = malonate dianion, dmphen = 2,9-dimethyl-1,10-phenanthroline) have been synthesized, and the structures of 1, 2, 4, and 5 determined by single-crystal X-ray diffraction. The structures of 1 and 2 consist of neutral [ReCl4(mu-mal)M(dmphen)2] dinuclear units where the metal ions are linked through a malonate ligand which adopts simultaneously the bidentate (at ReIV) and monodentate (at MII) coordination modes. The bridging carboxylate-malonate group in them …
(2-Chlorobenzyl)tris(2-pyridinethiolato)tin(IV).
2000
In the title compound, (2-chlorobenzyl)tris(pyridine-2-thiolato)-kappa(2)N,S;kappa2N,S;kappaS-tin(IV), [Sn(C7H6Cl)(C5H4NS)3], two of the three pyridine-2-thiolato ligands (SPy) are bidentate and one is monodentate. The bonding C atom of the 2-chlorobenzyl group, the S atom of the monodentate SPy and the S and N atoms of the two bidentate SPy ligands form a distorted octahedron around the Sn atom. The three S atoms and the N atom of one of the bidentate SPy ligands occupy the equatorial positions, while the N atom of the second bidentate SPy ligand and the C(CH2) atom are axial. The axial N-Sn-C angle of 157.9 (1) degree demonstrates the heavy distortion of the octahedron.
Coordination behaviour of sulfanilamide derivatives.
2000
Abstract Hg(II), Cd(II) and Zn(II) complexes with the ligands sulfadimethoxine, sulfamethoxypyridazine, sulfadiazine, sulfamerazine, sulfadimidine and sulfamethoxazole have been prepared and characterised by spectral data. 1H and 13C NMR have been used to interpret the structural characteristics of the complexes in solution. The X-ray crystal structures of [Hg(sulfamethoxypyridazinato)2] (2a), [Cd(sulfadimidinato)2(H2O)]·2H2O (4b) and [Zn(sulfamethoxazolato)2(py)2(H2O)2] (6d) have been determined. In complex 2a the Hg(II) ion lies on an inversion centre and exhibits linear coordination by two sulfonamidic nitrogen atoms [Hg–N(1)=2.071(4) A] of the two deprotonated sulfamethoxypyridazinato l…
Ferromagnetic Coupling between Low- and High-Spin Iron(III) Ions in the Tetranuclear Complex fac-{[FeIII{HB(pz)3}(CN)2(μ-CN)]3FeIII(H2O)3}· 6H2O ([HB…
2002
The novel mononuclear PPh4-fac-[FeIII{HB(pz)3}(CN)3]·H2O (1) [PPh4+= tetraphenylphosphonium cation; (HB(pz)3)- = hydrotris(1-pyrazolyl)borate] and tetranuclear fac-{[FeIII{HB(pz)3}(CN)2(μ-CN)]3FeIII(H2O)3}·6H2O (2) have been prepared and characterized by X-ray diffraction analysis. Crystal data for compound 1: monoclinic, space group P21/c, a = 9.575(3) A, b = 21.984(4) A, c = 16.863(3) A, β = 100.34(2)°, U = 3486(1) A3, Z = 4. Crystal data for compound 2: orthorhombic, space group Pnam, a = 14.084(3) A, b = 14.799(4) A, c = 25.725(5) A, U = 5362(2) A3, Z = 4. Compound 1 is a low-spin iron(III) compound with three cyanide ligands in fac arrangement and a tridentate pyrazolylborate ligand …
Organometallic complexes with biological molecules. XI. Solid state and in vivo investigations of some diorganotin(IV)-chloramphenicol and cycloserin…
1998
Abstract Diorganotin(IV) derivatives of chloramphenicol, {=D-(-)threo-2,2-dichloro-N-[ β -hydroxy- α -(hydroxymethyl)- β -(4-nitrophenyl)ethyl]acetamide (=Hchloramph)}, and D-cycloserine, {=(R)-4-amino-3-isoxazolidone [=Hcyclos]} have been prepared. The stoichiometries of the obtained compounds were R 2 SnClantib and R 2 Snantib 2 (antib −1 =chloramph −1 , R=methyl and phenyl; antib −1 =cyclos −1 , R=methyl). The solid state configuration of the complexes was investigated by I.R. and Mossbauer spectroscopy, from which structural hypotheses were inferred. In particular, the experimental data suggested monomer structures both for R 2 Sn(IV)Clchloramph and R 2 Sn(IV)chloramph 2 , in which chlo…
Synthesis, crystal structure and magnetic properties of the three-dimensional compound [Na2Ni(mal)2(H2O)6]n (H2mal=malonic acid)
2000
Abstract A new three-dimensional nickel–sodium compound of formula [Na 2 Ni(mal) 2 (H 2 O) 6 ] n (H 2 mal=malonic acid) was prepared and its structure was determined by X-ray diffraction methods. Four malonate–oxygen atoms and two trans -(Ni) or cis -(Na) coordinated water molecules build distorted octahedral surroundings around the metal atoms. The malonate group exhibits bidentate (Ni) and tetrakis-monodentate (Na) coordination modes. The structure can be described as corrugated sheets of malonato-containing Ni(II) and Na(I) cations which grow in the (101) plane, each sheet being linked to the adjacent one in the [101] direction through bis(μ-aqua)disodium(I) units. Within each corrugated…