Synthesis, characterization, and x-ray structure determination of chromium(I) nitrosyl complexes with macrocyclic ligands

1977 ◽  
Vol 16 (5) ◽  
pp. 1055-1060 ◽  
Author(s):  
Dennis. Wester ◽  
Robert C. Edwards ◽  
Daryle H. Busch

2000 ◽  
Vol 53 (9) ◽  
pp. 799 ◽  
Author(s):  
Ian M. Atkinson ◽  
David C. R. Hockless ◽  
Leonard F. Lindoy ◽  
Owen A. Matthews ◽  
George V. Meehan ◽  
...  

The synthesis and single-crystal X-ray structure determination of a new cage molecule containing four oxygen, two sulfur, and two nitrogen heteroatoms are described. The structure determination shows that a twist occurs about each (tribenzyl) nitrogen bridgehead so that an overall helical configuration within putative quasi-2 symmetry is generated; both nitrogens have their lone pairs orientatedexo. Single crystals of this compound are homochiral. Semiempirical MO calculations have been used to probe the topological rigidity of this system relative to the more symmetrical analogue incorporating six oxygen and two nitrogen heteroatoms reported previously. The introduction of the sulfur atoms appears to restrict the facile interconversion between enantiomers that was predicted for the N2O6-analogue mentioned above. The implications of the structure for the design of larger cages are discussed.



2001 ◽  
Vol 56 (9) ◽  
pp. 901-907 ◽  
Author(s):  
Marco H. Klingele ◽  
Gunther Steinfeld ◽  
Berthold Kersting

Abstract The ability of the aromatic tetraaldehyde l,2-bis(4-tert-butyl-2,6-diformylphenylsulfanyl)-ethane (1) to function as a precursor in the preparation of binucleating hexaamine-dithiolate ligands has been investigated. Reductive amination of compound 1 with bis(aminoethyl)amine under medium-dilution conditions affords the macrobicyclic hexaamine-dithioether compound L1. Deprotection of the [1+2] condensation product gives the corresponding 24-membered hexa-amine-dithiophenol ligand H2L2. The formulation of L1 as a macrobicyclic amine-thioether was confirmed by an X-ray crystal structure determination of the tetranuclear nickel(II) complex of L1, [{(L1)Ni2Cl2}2(μ-Cl)3](BPh4) (2b). The formulation of the doubly deprotonated form (L2)2- of H2L2 as a 24-membered amine-thiophenolate ligand was confirmed by an X-ray crystal structure determination of the dinuclear cobalt(III) complex, [(L2)CoIII(μ-OH)](ClO4)2 · Cl (3). The preparation and the crystal structures of the new compounds are described.



Sign in / Sign up

Export Citation Format

Share Document