2-Aminoisobutyric acid in Co(II) and Co(II)/Ln(III) chemistry: homometallic and heterometallic clusters.
The synthesis and magnetic properties of 13 new homo- and heterometallic Co(II) complexes containing the artificial amino acid 2-amino-isobutyric acid, aibH, are reported: [Co(II)(4)(aib)(3)(aibH)(3)(NO(3))](NO(3))(4)·2.8CH(3)OH·0.2H(2)O (1·2.8CH(3)OH·0.2H(2)O), {Na(2)[Co(II)(2)(aib)(2)(N(3))(4)(CH(3)OH)(4)]}(n) (2), [Co(II)(6)La(III)(aib)(6)(OH)(3)(NO(3))(2)(H(2)O)(4)(CH(3)CN)(2)]·0.5[La(NO(3))(6)]·0.75(ClO(4))·1.75(NO(3))·3.2CH(3)CN·5.9H(2)O (3·3.2CH(3)CN·5.9H(2)O), [Co(II)(6)Pr(III)(aib)(6)(OH)(3)(NO(3))(3)(CH(3)CN)(6)]·[Pr(NO(3))(5)]·0.41[Pr(NO(3))(3)(ClO(4))(0.5)(H(2)O)(1.5)]·0.59[Co(NO(3))(3)(H(2)O)]·0.2(ClO(4))·0.25H(2)O (4·0.25H(2)O), [Co(II)(6)Nd(III)(aib)(6)(OH)(3)(NO(3))(2.8)(CH(3)OH)(4.7)(H(2)O)(1.5)]·2.7(ClO(4))·0.5(NO(3))·2.26CH(3)OH·0.24H(2)O (5·2.26CH(3)OH·0.24H(2)O), [Co(II)(6)Sm(III)(aib)(6)(OH)(3)(NO(3))(3)(CH(3)CN)(6)]·[Sm(NO(3))(5)]·0.44[Sm(NO(3))(3)(ClO(4))(0.5)(H(2)O)(1.5)]·0.56[Co(NO(3))(3)(H(2)O)]·0.22(ClO(4))·0.3H(2)O (6·0.3H(2)O), [Co(II)(6)Eu(III)(aib)(6)(OH)(3)(NO(3))(3)(CH(3)OH)(4.87)(H(2)O)(1.13)](ClO(4))(2.5)(NO(3))(0.5)·2.43CH(3)OH·0.92H(2)O (7·2.43CH(3)OH·0.92H(2)O), [Co(II)(6)Gd(III)(aib)(6)(OH)(3)(NO(3))(2.9)(CH(3)OH)(4.9)(H(2)O)(1.2)]·2.6(ClO(4))·0.5(NO(3))·2.58CH(3)OH·0.47H(2)O (8·2.58CH(3)OH·0.47H(2)O), [Co(II)(6)Tb(III)(aib)(6)(OH)(3)(NO(3))(3)(CH(3)CN)(6)]·[Tb(NO(3))(5)]·0.034[Tb(NO(3))(3)(ClO(4))(0.5)(H(2)O)(0.5)]·0.656[Co(NO(3))(3)(H(2)O)]·0.343(ClO(4))·0.3H(2)O (9·0.3H(2)O), [Co(II)(6)Dy(III)(aib)(6)(OH)(3)(NO(3))(2.9)(CH(3)OH)(4.92)(H(2)O)(1.18)](ClO(4))(2.6)(NO(3))(0.5)·2.5CH(3)OH·0.5H(2)O (10·2.5CH(3)OH·0.5H(2)O), [Co(II)(6)Ho(III)(aib)(6)(OH)(3)(NO(3))(3)(CH(3)CN)(6)]·0.27[Ho(NO(3))(3)(ClO(4))(0.35)(H(2)O)(0.15)]·0.656[Co(NO(3))(3)(H(2)O)]·0.171(ClO(4)) (11), [Co(II)(6)Er(III)(aib)(6)(OH)(4)(NO(3))(2)(CH(3)CN)(2.5)(H(2)O)(3.5)](ClO(4))(3)·CH(3)CN·0.75H(2)O (12·CH(3)CN·0.75H(2)O), and [Co(II)(6)Tm(III)(aib)(6)(OH)(3)(NO(3))(3)(H(2)O)(6)]·1.48(ClO(4))·1.52(NO(3))·3H(2)O (13·3H(2)O). Complex 1 describes a distorted tetrahedral metallic cluster, while complex 2 can be considered to be a 2-D coordination polymer. Complexes 3-13 can all be regarded as metallo-cryptand encapsulated lanthanides in which the central lanthanide ion is captivated within a [Co(II)(6)] trigonal prism. dc and ac magnetic susceptibility studies have been carried out in the 2-300 K range for complexes 1, 3, 5, 7, 8, 10, 12, and 13, revealing the possibility of single molecule magnetism behavior for complex 10.
Department of Chemistry, The University of Crete, Voutes 71003, Herakleion, Greece.
George J
GJ
Sopasis
Maria
M
Orfanoudaki
Pavlos
P
Zarmpas
Aggelos
A
Philippidis
Milosz
M
Siczek
Tadeusz
T
Lis
James R
JR
O'Brien
Constantinos J
CJ
Milios