Heterospin Systems Constructed from [Cu2Ln]3+ and [Ni(mnt)2]1-,2- Tectons: First 3p-3d-4f Complexes (mnt = Maleonitriledith
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- 作者：Augustin M. Madalan ; Narcis Avarvari ; Marc Fourmigué ; Rodolphe Clé ; rac ; Liviu F. Chibotaru ; Sergiu Clima ; Marius Andruh
- 刊名：Inorganic Chemistry
- 出版年：2008
- 出版时间：February 4, 2008
- 年：2008
- 卷：47
- 期：3
- 页码：940 - 950
- 全文大小：541K
- 年卷期：v.47,no.3(February 4, 2008)
- ISSN：1520-510X
文摘
New heterospin complexes have been obtained by combining the binuclear complexes [{Cu(H2O)L1}Ln(O2NO)3] or[{CuL2}Ln(O2NO)3] (L1 = N,N'-propylene-di(3-methoxysalicylideneiminato); L2 = N,N'-ethylene-di(3-methoxysalicylideneiminato); Ln = Gd3+, Sm3+, Tb3+), with the mononuclear [CuL1(2)] and the nickel dithiolene complexes [Ni(mnt)2]q- (q= 1, 2; mnt = maleonitriledithiolate), as follows: 1
tities/infin.gif">[{CuL1}2Ln(O2NO){Ni(mnt)2}]·Solv·CH3CN (Ln = Gd3+, Solv =CH3OH (1), Ln = Sm3+, Solv = CH3CN (2)) and [{(CH3OH)CuL2}2Sm(O2NO)][Ni(mnt)2] (3) with [Ni(mnt)2]2-, [{(CH3CN)CuL1}2Ln(H2O)][Ni(mnt)2]3·2CH3CN (Ln = Gd3+ (4), Sm3+ (5), Tb3+ (6)), and [{(CH3OH)CuL2}{CuL2}Gd(O2NO){Ni(mnt)2}][Ni(mnt)2]·CH2Cl2 (7) with [Ni(mnt)2]tities/bull.gif">-. Trinuclear, almost linear, [CuLnCu] motifs are found in all the compounds.In the isostructural 1 and 2, two trans cyano groups from a [Ni(mnt)2]2- unit bridge two trimetallic nodes through axialcoordination to the Cu centers, thus leading to the establishment of infinite chains. 3 is an ionic compound, containingdiscrete [{(CH3OH)CuL2}2Sm(O2NO)]2+ cations and [Ni(mnt)2]2- anions. Within the series 4-6, layers of discrete [CuLnCu]3+motifs alternate with stacks of interacting [Ni(mnt)2]tities/bull.gif">- radical anions, for which two overlap modes, providing two differenttypes of stacks, can be disclosed. The strength of the intermolecular interactions between the open-shell species isestimated through extended Hückel calculations. In compound 7, [Ni(mnt)2]tities/bull.gif">- radical anions coordinate group one of theCu centers of a trinuclear [Cu2Gd] motif through a CN, while discrete [Ni(mnt)2]tities/bull.gif">- units are also present, overlapping inbetween, but also with the coordinated ones. Furthermore, the [Cu2Gd] moieties dimerize each other upon linkage bytwo nitrato groups, both acting as chelate toward the gadolinium ion from one unit and monodentate toward a Cu ionfrom the other unit. The magnetic properties of the gadolinium-containing complexes have been determined. Ferromagneticexchange interactions within the trinuclear [Cu2Gd] motifs occur. In the compounds 4 and 7, the [Ni(mnt)2]tities/bull.gif">- radicalanions contribution to the magnetization is clearly observed in the high-temperature regime, and most of it vanishes upontemperature decrease, very likely because of the rather strong antiferromagnetic exchange interactions between theopen-shell species. The extent of the exchange interaction in the compound 7, which was found to be antiferromagnetic,between the coordinated Cu center and the corresponding [Ni(mnt)2]tities/bull.gif">- radical anion, bearing mostly a 3p spin type, wasestimated through CASSCF/CASPT2 calculations. Compound 6 exhibits a slow relaxation of the magnetization.
tities/infin.gif">[{CuL1}2Ln(O2NO){Ni(mnt)2}]·Solv·CH3CN (Ln = Gd3+, Solv =CH3OH (1), Ln = Sm3+, Solv = CH3CN (2)) and [{(CH3OH)CuL2}2Sm(O2NO)][Ni(mnt)2] (3) with [Ni(mnt)2]2-, [{(CH3CN)CuL1}2Ln(H2O)][Ni(mnt)2]3·2CH3CN (Ln = Gd3+ (4), Sm3+ (5), Tb3+ (6)), and [{(CH3OH)CuL2}{CuL2}Gd(O2NO){Ni(mnt)2}][Ni(mnt)2]·CH2Cl2 (7) with [Ni(mnt)2]tities/bull.gif">-. Trinuclear, almost linear, [CuLnCu] motifs are found in all the compounds.In the isostructural 1 and 2, two trans cyano groups from a [Ni(mnt)2]2- unit bridge two trimetallic nodes through axialcoordination to the Cu centers, thus leading to the establishment of infinite chains. 3 is an ionic compound, containingdiscrete [{(CH3OH)CuL2}2Sm(O2NO)]2+ cations and [Ni(mnt)2]2- anions. Within the series 4-6, layers of discrete [CuLnCu]3+motifs alternate with stacks of interacting [Ni(mnt)2]tities/bull.gif">- radical anions, for which two overlap modes, providing two differenttypes of stacks, can be disclosed. The strength of the intermolecular interactions between the open-shell species isestimated through extended Hückel calculations. In compound 7, [Ni(mnt)2]tities/bull.gif">- radical anions coordinate group one of theCu centers of a trinuclear [Cu2Gd] motif through a CN, while discrete [Ni(mnt)2]tities/bull.gif">- units are also present, overlapping inbetween, but also with the coordinated ones. Furthermore, the [Cu2Gd] moieties dimerize each other upon linkage bytwo nitrato groups, both acting as chelate toward the gadolinium ion from one unit and monodentate toward a Cu ionfrom the other unit. The magnetic properties of the gadolinium-containing complexes have been determined. Ferromagneticexchange interactions within the trinuclear [Cu2Gd] motifs occur. In the compounds 4 and 7, the [Ni(mnt)2]tities/bull.gif">- radicalanions contribution to the magnetization is clearly observed in the high-temperature regime, and most of it vanishes upontemperature decrease, very likely because of the rather strong antiferromagnetic exchange interactions between theopen-shell species. The extent of the exchange interaction in the compound 7, which was found to be antiferromagnetic,between the coordinated Cu center and the corresponding [Ni(mnt)2]tities/bull.gif">- radical anion, bearing mostly a 3p spin type, wasestimated through CASSCF/CASPT2 calculations. Compound 6 exhibits a slow relaxation of the magnetization.