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1980 (2)
1Author    Il-Hwan Suh, Gabriela Weber, Menachem Kaftory, Wolfram Saenger, Heinz Sieger, Fritz VögtleRequires cookie*
 Title    Structural Change of a Linear Polyether upon Complex Formation. l.ll-Bis(2-acetylaminophenoxy)-3.6.9-trioxaundecane and its KSCN Complex"  
 Abstract    The title compound (1) was crystallized as free ligand and as its (1 • KSCN)2 • H20 complex. Crystallographic data are, for the former: space group C 2/c, a — 31.110(9), b = 4.608(4), c = 17.188(6) A, ß = 105.27(8)°, Z = 2, Dm = 1.25 gem-3 ; for the latter: space group P2i, a = 11.044(3), b = 18.310(4), c = 14.485(4) Ä, ß = 97.49(2)°, Z = 4, Dm = 1.27 gem -3 . Crystal structures were solved by direct methods using X-ray diffrakto-meter data and least squares refinements converged at 10.8% for 1 and at 7.6% for (1 • KSCN)2 • H20. The free ligand (1) is S-shaped and, upon K+-complexation, changes signs of some gauche O-C-C-O torsion angles while C-C-O-C angles remain trans. In (1 • KSCN)2 • H20, there are two complex molecules 1 A • KSCN • H20 (I) and 1 B • KSCN (II). The ligands are wrapped circularly around K + and coordinated with only four of the five polyether oxygens. K+ interacts further with H20 in (I) and with N of SCN~ in II and, in both complexes, with acetylamino oxygen of adjacent 1. The latter interaction leads to polymeric structures not observed previously for similar complexes. 
  Reference    Z. Naturforsch. 35b, 352—359 (1980); received November 28 1979 
  Published    1980 
  Keywords    Polyether, KSCN Complex, Polymer Formation, X-ray 
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 TEI-XML for    default:Reihe_B/35/ZNB-1980-35b-0352.pdf 
 Identifier    ZNB-1980-35b-0352 
 Volume    35 
2Author    K. K. Chacko, W. SaengerRequires cookie*
 Title    Crystal and Molecular Structure of l,ll-bis(Tropolone)-3,6,9-trioxaundecane * Rbl a  
 Abstract    The complex between the polyether ligand l,ll-bis(tropolone)-3,6,9-trioxaundecane and Rbl crystallizes in space group P2i/c with cell dimensions a — 11.383(4), b = 14.493(5), c = 16.122(6) A and ß = 111.02(5)° with Z = 4. The structure was solved on the basis of 3734 X-ray reflections measured on a diffractometer with CuKa-radiation and refined to an R of 0.101. The polyether wraps around the Rb + in a circular structure. One of the tropolone rings is elevated in order to avoid collision. Rb + is located 1.224(6) A above the plane formed by five oxygen atoms of the ligand, it is coordinated to I -(3.666(2)Ä) and to all oxygens. The Rb+ • • • O distances of the least electronegative "ester oxygens", 3.14(1) A and 3.18(1) A are significantly longer compared to the other Rb+---0 distances in the range 2.81(1) A to 3.08(1) A. The conformation about the C-C and C-0 bonds of the ligand are gauche and trans as generally found in such molecules. The two tropolone seven-membered rings are slightly non-planar and display an envelope-type structure. 
  Reference    Z. Naturforsch. 35b, 1533—1537 (1980); received August 7 1980 
  Published    1980 
  Keywords    Polyether, Tropolone, Rbl Complex, X-ray 
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 TEI-XML for    default:Reihe_B/35/ZNB-1980-35b-1533.pdf 
 Identifier    ZNB-1980-35b-1533 
 Volume    35