A Singular Noninterpenetrating Coordination Polymer with the Pt3O4 Structure Containing Naked [Na+]4 Units

2006

The homoleptic low-spin complex [Fe(L)3]2+ where L is the bisbidentate ligand 1,10-phenanthroline-5,6-dione, coordinates Na+ ions via exo-oriented dione groups defining a three-dimensional cationic network {[Fe(L)3]4Na3}11+}n with Pt3O4 topology. The large volume generated by the network is filled with 11 perchlorate ions, 7 "NaClO4" ionic pairs, and 9 H2O molecules. Singular [Na+]4 units, in which the Na+ ions are practically uncoordinated, are formed.

Dimer complexes of 2,4-toluenediamine-N,N,N′,N′-tetraacetic acid (2,4-TDTA) with copper(II), nickel(II), cobalt(II), zinc(II) and manganese(II). Stud…

1997

Abstract Potentiometric investigations in aqueous solution at 25°C and ionic strength 0.1 mol dm−3 KCl show that 2 2,4-toluenediamine-N,N,N′N′-tetraacetic acid (2,4-TDTA) forms with Cu(II), Ni(II), Co(II), Zn(II) and Mn(II) the following complexes (ligand, H4L): monomers [MH2L], [MHL]− and [ML]2−; dimers [M2HL2]3− and [M2L2]4−; with excess of ligand [MH2L2]4−, [MHL2]5− and [ML2]6− (Cu(II), Ni(II) and Zn(II)) and with excess of metal [M2HL]+ (Ni(II), Co(II)and Mn(II) and [M2L] (Cu(II)). The formation constants of the complexes have been determined. The species distribution diagrams indicate that a concentrated solution with a ligand:metal ratio 1:1 at pH 6 is suitable for the synthesis of cr…

A study of the exchange interaction through phenolato, oximato and oxamidato bridges in MnIICuII dimers. Crystal structure of [Cu(salen)Mn(hfa)2]

1993

Abstract Three new heterodinuclear CuIIMnII complexes of formula [Cu(salen)Mn(hfa)2] (1), [Cu(pdmg)Mn(phen)2](ClO4)2·2.5H2O (2) and [Cu(apox)Mn(bpy)2](ClO4]2·0.5H2O (3) (salen=N,N′-ethylenebis(salicylideneiminate), hfa=hexafluoroacetylacetonate, pdmg=3,9-dimethyl-4,8-diazaundeca-3,8-diene-2,10-dione dioximate, phen=1,10- phenanthroline, apox=N,N′-bis(3-aminopropyl)oxamidate and bipy=2,2′-bipyridyl) have been synthesized. The crystal and molecular structure of 1 has been determined by X-ray diffraction methods. It crystallizes in the triclinic system, space group P 1 with cell constants a=15.584(4), b=12.039(3), c=9.470(2) A, α=113.83(2), β=107.17(3), γ=84.28(3)°; V=1552(1) A3, D (calc., Z=2…

Structure and magnetic properties of a linear oximato-bridged tetranuclear copper(II) complex

1998

Abstract The tetranuclear copper(II) complex of formula [Cu2(dmg)(Hdmg)(terpy)]2(ClO4)2 (1) (H2dmg = dimethylglyoxime and terpy = 2,2′:6′,2″-terpyridine) has been synthesized and its crystal structure determined by X-ray diffraction methods. It crystallizes in the triclinic system, space group P(−1), with a = 14.382(3), b = 13.728(3), c = 8.979(2) A, α = 96.99(2), β = 111.85(2), γ = 111.22(3)°, V = 1465.0(9) A3, Z = 1, Dc = 1.607 g cm−3, Mr = 1418.0, F(000) = 719, λ(Mo Kα) = 0.71073 A, μ(Mo Kα) = 16.61 cm−1 and T = 298 K. A total of 4891 reflections were measured over the range 2 ≤ θ ≤ 25° and 4393 of them were unique (I > 2.5σ(I) and used in the structural analysis. The structure of 1 may …

Spin-crossover in the [Fe(abpt)2(NCX)2] (X=S, Se) system: Structural, Magnetic, calorimetric and photomagnetic studies

1999

[EN] The compounds [Fe(abpt)(2)(NCS)(2)] (1) and [Fe(abpt)(2)(NCSe)(2)] (2) with abpt = 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole have been synthesized. The X-ray structures have been determined at 293 K. 1 and 2 are isostructural and crystallize in the monoclinic space group P2(1)/n with Z = 2, a = 8.538(8), b = 10.246(8), c = 16.45(2) Angstrom, beta = 93.98(9)degrees for 1 and a = 8.623(2), b = 10.243(3), c = 16.585(3) Angstrom, beta = 93.19(2)degrees for 2. In both complexes, the coordination core has a similar pseudo-octahedral geometry with the NCS- (1) and NCSe- (2) groups in the trans-position. Variable-temperature magnetic susceptibility data give evidence for a low-spin (LS)high…

Synthese, Struktur und magnetische Eigenschaften eines achtkernigen Nickel(II)-Komplexes mit einer zentralenhexahedro-Ni8-Einheit

1996

Study of the interaction between [Cu(bipy)]2+ and oxalate in dimethyl sulfoxide. Crystal structure of [Cu2(bipy)2(H2O)2ox]SO4·[Cu(bipy)ox]

1991

Abstract A study of complex formation between [Cu(bipy)]2+ and ox2− (bipy and ox2− being 2,2′-bipyridyl and the dianion of oxalic acid), has been carried out by potentiometry in dimethyl sulfoxide solution. The constants of the equilibria and are log β110 = 11.165(1) and log β210 = 13.185(5) at 25 °C and 0.1 mol dm−3 tetra-n- butylammonium perchlorate. The high values of these constants are consistent with the symmetrical bidentate and bis-bidentate modes of oxalate in [Cu(bipy)ox] and [Cu2(bipy)2ox]2+ units, respectively, as shown by X-ray diffraction studies. Well-formed single crystals of [Cu2(bipy)2(H2O)2ox]SO4· [Cu(bipy)ox] were grown from aqueous solutions and characterized by X-ray d…

Synthesis, Crystal Structure, and Magnetic Properties of an Octanuclear Nickel(II) Complex with ahexahedro-Ni8 Core

1996

Spiroterpenoids from Hypericum reflexum

1993

Abstract Two new spiroterpenoids, hyperireflexolide A and B, were isolated from Hypericum reflexum . Their structures and stereochemistry were established by spectroscopic methods, including 13 C NMR, DEPT and HMQC, and X-ray data.