
%0 Journal Article
%A Engelhardt, LM 
%A Furphy, BM 
%A Harrowfield, JM 
%A Kepert, DL 
%A White, AH 
%A Wilner, FR 
%T Coordination Chemistry of the Calixarenes. II. Europium(III) and p-t-Butyl Calix[6]arene
%J Australian Journal of Chemistry
%D 1988/09/01
%V 41
%N 9
%P 1465-1476
%K 
%R https://doi.org/10.1071/CH9881465
%U https://www.publish.csiro.au/paper/CH9881465 
%X The possible nature of p-t-butyl-calix [6] arene complexes of lanthanide elements has been explored by determination of the single-crystal X-ray structure of a complex with a 1:2 europium/ ligand ratio, obtained from dimethylformamide (dmf &#8801; Me2NCHO) solution. This complex is formulated as [ Eu (LH4)(Me2NCHO)6(OH)].LH6.~4Me2NCHO (LH6 = p-t-butyl-calix [6] arene) on the basis of the structure determination. Crystals are monoclinic, P21/n, a 36.11(3), b 23.35(2), c 21.85(2)&#506;, &#946; 97.46(6)&#176;, Z = 4 formula units; R was 0.11 for 8488 'observed' reflections. The complex is remarkable in that the only interaction of either of the two calixarene  ligands (one presumably doubly or triply deprotonated ) with the eight-coordinate europium atom is by way of one behaving as monodentate, the other having no interaction. Eu -O( calix ) is 2.35(1) &#506;; Eu -O( dmf )6 range from 2.38(2) to 2.49(2)&#506;, and Eu -O(H &#189;?) is 2.49(2)&#506;. 
