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'Macrocyclic N4 Donor Ligands' in keywords Facet   Publication Year 1996  [X]
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1996[X]
1Author    R.Alf Feldhaus, JensK. Öppe, R. Ain, ErM. AttesRequires cookie*
 Title    Komplexe eines vierzehngliedrigen Tetraazadibenzo  
 Abstract    Makrocyclus. Strukturen des freien und zweifach protonierten Liganden und seiner Nickel(II)-, Kupfer(II)-, Zink(II)-und Palladium(II)-Komplexe C om plexes of a 14-M em bered N 4 D ibenzo M acrocycle. Crystal S tructures of the Free and D ip ro to n ated Ligand and of its N ickel(II), C o p p er(II), Z in k (II) and P alladium (II) C om plexes The synthesis and structural characterisation of complexes of the 14-membered macrocy­ clic trans-N4 dibenzo ligand 5,6,7,8,9,14.15,16,17,18-decahydrodibenzo[e,l][l,4, 8,1 l]-tetraaza-cyclotetradecine (L2) is described. The crystal structures of six compounds were determined by single crystal X-ray diffraction. The free ligand L2 has a saddle-shaped structure with short intramolecular hydrogen bonds. The N —N distances are 289 pm. The diprotonated species [H2L2]2+ has a different conformation due to intra-and intermolecular hydrogen bonds. TTie ligand is folded along an N —N axis in c/s-[Ni(L2)(H 20) 2]2+, but displays a saddle­ shaped structure in the Cu(II), Z n(II) and Pd(II) complexes with a more or less planar arrangem ent of the four N donor atoms. The metal atoms are incorporated within the macro-cyclic cavity in [Cu(L2)(CF3S03)]+ and [Pd(L2)]2+. The metal-to-nitrogen bond lengths herein are rather small. Zn(II) is five-coordinate in [Zn(L2)(Cl)]+. The coordination polyhedron is intermediate between a trigonal bipyramid and a square pyramid. In all complexes the metal-to-ligand distances originating at the nitrogen atoms in /^-position (with respect to the arom a­ tic ring) are significantly shorter then the donor bonds of the 1 anilinic' N atoms. 
  Reference    Z. Naturforsch. 51b, 869—878 (1996); eingegangen am 6. November 1995 
  Published    1996 
  Keywords    Macrocyclic N4-Donor Ligands, Transition Metal Complexes, Crystal Structures 
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 TEI-XML for    default:Reihe_B/51/ZNB-1996-51b-0869.pdf 
 Identifier    ZNB-1996-51b-0869 
 Volume    51 
2Author    Tetraazadibenzo Macrocycle, Ralf Feldhaus, Jens Köppe, Rainer Mattes, Ulrich VoetRequires cookie*
 Title    Synthesis and Structures of the Vanadyl, Cobalt(III), Nickel(II), Copper(II), Zinc(II) and Palladium(II) Complexes of a 14-Membered Unsaturated  
 Abstract    The synthesis and structural characterisation of complexes of the 14-membered macrocyclic trans-N4 dibenzo ligand 7,8,9,16,17.18-hexahydrodibenzo[e,l][ 1,4, 8.11 ]-tetraazacyclotetra-decine (L 1) is described. The crystal structures of six compounds were determined by single crystal X-ray diffraction. In [CuL1 ]2+ the metal atom is tightly bound within the macrocyclic cavity. The Cu-N bonds [201.2(3) and 191.8(3) pm] are rather short. Zn(II) is penta-coordinated in [Zn(L')C l]+ with the metal center outside the cavity. L 1 is deprotonated at one or both secondary amine functions in the complexes [N i(L '-H)]+, [Co(L -2H)]+, [VO(L'-2H)] and [Pd(L'-2H)]. With the exception of [VO (L'-2H)] the metal ions assume nearly square planar N4-coordination, which is very rare for Co(III). Salts of [Co(L'-2H)]+ display a temperature independent magnetic moment of 0,64 B. M. The nickel, cobalt and palladium complexes show remarkably short metal-nitrogen bond distances: Ni-N [183.8(8)], Co-N [181.8(2)] and Pd-N [194.5(6) pm], respectively. The UV/Vis and EPR spectra, and the electrochemical behaviour of some of these complexes are also discussed. 
  Reference    Z. Naturforsch. 51b, 1449—1458 (1996); eingegangen am 1. April 1996 
  Published    1996 
  Keywords    Macrocyclic N4-Donor Ligands, Transition Metal Complexes, Crystal Structure 
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 TEI-XML for    default:Reihe_B/51/ZNB-1996-51b-1449.pdf 
 Identifier    ZNB-1996-51b-1449 
 Volume    51