New heterospin comp
lexes have been obtained by combining the binuc
lear comp
lexes [{Cu(H
2O)L
1}Ln(O
2NO)
3] or[{CuL
2}Ln(O
2NO)
3] (L
1 =
N,
N'-propy
lene-di(3-methoxysa
licy
lideneiminato); L
2 =
N,
N'-ethy
lene-di(3-methoxysa
licy
lideneiminato); Ln = Gd
3+, Sm
3+, Tb
3+), with the mononuc
lear [CuL
1(2)] and the nicke
l dithio
lene comp
lexes [Ni(mnt)
2]
q- (
q= 1, 2; mnt = ma
leonitri
ledithio
late), as fo
llows:
1![](/images/entities/infin.gif)
[{CuL
1}
2Ln(O
2NO){Ni(mnt)
2}]·So
lv·
CH3CN (Ln = Gd
3+, So
lv =CH
3OH (
1), Ln = Sm
3+, So
lv = CH
3CN (
2)) and [{(CH
3OH)CuL
2}
2Sm(O
2NO)][Ni(mnt)
2] (
3) with [Ni(mnt)
2]
2-, [{(CH
3CN)CuL
1}
2Ln(H
2O)][Ni(mnt)
2]
3·2CH
3CN (Ln = Gd
3+ (
4), Sm
3+ (
5), Tb
3+ (
6)), and [{(CH
3OH)CuL
2}{CuL
2}Gd(O
2NO){Ni(mnt)
2}][Ni(mnt)
2]·CH
2C
l2 (
7) with [Ni(mnt)
2]
ll.gif">-. Trinuc
lear, a
lmost
linear, [CuLnCu] motifs are found in a
ll the compounds.In the isostructura
l 1 and
2, two trans cyano groups from a [Ni(mnt)
2]
2- unit bridge two trimeta
llic nodes through axia
lcoordination to the Cu centers, thus
leading to the estab
lishment of infinite
chains.
3 is an ionic compound, containingdiscrete [{(CH
3OH)CuL
2}
2Sm(O
2NO)]
2+ cations and [Ni(mnt)
2]
2- anions. Within the series
4-
6,
layers of discrete [CuLnCu]
3+motifs a
lternate with stacks of interacting [Ni(mnt)
2]
ll.gif">- radica
l anions, for whi
ch two over
lap modes, providing two differenttypes of stacks, can be disc
losed. The strength of the intermo
lecu
lar interactions between the open-she
ll species isestimated through extended H&uum
l;cke
l ca
lcu
lations. In compound
7, [Ni(mnt)
2]
ll.gif">- radica
l anions coordinate group one of theCu centers of a trinuc
lear [Cu
2Gd] motif through a CN, whi
le discrete [Ni(mnt)
2]
ll.gif">- units are a
lso present, over
lapping inbetween, but a
lso with the coordinated ones. Furthermore, the [Cu
2Gd] moieties dimerize ea
ch other upon
linkage bytwo nitrato groups, both acting as
che
late toward the gado
linium ion from one unit and monodentate toward a Cu ionfrom the other unit. The magnetic properties of the gado
linium-containing comp
lexes have been determined. Ferromagneticex
change interactions within the trinuc
lear [Cu
2Gd] motifs occur. In the compounds
4 and
7, the [Ni(mnt)
2]
ll.gif">- radica
lanions contribution to the magnetization is c
lear
ly observed in the high-temperature regime, and most of it vanishes upontemperature decrease, very
like
ly because of the rather strong antiferromagnetic ex
change interactions between theopen-she
ll species. The extent of the ex
change interaction in the compound
7, whi
ch was found to be antiferromagnetic,between the coordinated Cu center and the corresponding [Ni(mnt)
2]
ll.gif">- radica
l anion, bearing most
ly a 3p spin type, wasestimated through CASSCF/CASPT2 ca
lcu
lations. Compound
6 exhibits a s
low re
laxation of the magnetization.