ISSN:
1573-1111
Keywords:
Crown ethers
;
rare-earth metals
;
crystal structure
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract An X-ray diffraction study of the complexes [Nd(N03)3(Bl2C4)] (I), [La(NO3)3(Bl2C4)(H2O)]·MeCN (II), and [Er(NO3)3(H2O)3]·2(Bl2C4)·MeCN (III), (B12C4 = benzo-12-crown-4) has been carried out. Crystals ofI are monoclinic,a = 8.050(2),b = 29.92(1),c = 7.741(2) Å,β = 102.71(2)°, space groupP21/c,Z = 4,R = 0.047 for 4718 reflections. Crystals of II are triclinic,a = 8.211(2),b = 10.613(3),c = 12.837(4)Å,a = 94.46(3),β = 108.19(2), γ = 89.98(3)°, space groupPT,Z = 2,R = 0.037 for 5611 reflections. Crystals ofIII are monoclinic,a = 9.847(3),b = 17.201(4),c = 21.664(5)Å,β = 100.85(2)°, space groupP21/n,Z = 4,R = 0.040 for 8328 reflections. The chemical structures of the complexes have been elucidated. The correlation between the radius of a particular lanthanide-ion and its coordination number (10 inI, 11 inII and 9 inIII) and consequently its influence on the composition of the complex is discussed. The possibilities of conformational changes in the B12C4 molecule depending on the type and size of the coordinated moiety (ions Nd(III) and La(III) inI andII and the H2O molecule inIII) are considered.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01066203
